S292 Study Guide

Objectives:
For all units:
1) Define and use, or recognize definitions and applications of, each of the key terms noted in the study guide for this unit.
2) Locate up to date news of fossil, archaeological and genetic evidence relevant to each unit, on the S292 web site.
3) Make use of up-to date evidence and information on S292 web site, in the appropriate context.

Unit 1 Man's Place in Nature
Unit 1 is introductory and sets the historical background for theories and studies of human evolution. Thomas Henry Huxley championed the book by Charles Darwin called 'The Origin of Species'. The book was published in 1859 and in it Darwin set out his views on the origin of species by natural selection, views that he had been forming since his famous five-year voyage around the World in HMS Beagle.

T H Huxley's book, "Evidence as to man's place in nature" published in 1863, represents the first time humans were seen as part of nature, not apart from nature. Nevertheless, even Huxley, like his contemporaries, regarded humans as being "above" other animals, having special qualities.

Objectives:
1.1 Explain, from a historical point of view, the concept that Homo sapiens evolved from a type of ancestral ape.
1.2 Demonstrate how Homo sapiens has always been considered as a very special type of animal.

SAQ 1.1 (Objectives 1.1, 1.2)
Give two examples of how the concept of evolution was incorporated into earlier ideas that humans are 'above' and superior to animals (write about 100-120 words).

Unit 2 Human Evolution as Narrative
This unit shows how the inherent love of humans for stories means that narrative reports of human evolution are common. Misia Landau has analysed professional accounts of human origins to demonstrate how paleoanthropology is particularly liable to be set in a narrative form. Landau has shown that narrative accounts of human evolution have the structure of the hero folk tale.

The final paragraph of unit 2 makes an important point about use of language when explaining evolutionary scenarios.
It is worth highlighting this paragraph!

Objectives
2.1 Explain the concept of a narrative and give an example in the context of human evolution.
2.2 Recognize the four key events in human evolution: origin of terrestriality, bipedalism, encephalization, and culture/civilization, and appreciate that paleoanthroplologists disagree about the order in which they are thought to have occurred.
2.3 Explain the concept of a hero myth type of account of human evolution as defined by Landau and give an example.

SAQ 2.1 (Objectives 2.1-2.3)
Describe the sequence of events in the cartoon on p. 7 as a hero folk tale. Write no more than 150 words.

Unit 3 Historical News
This unit explores the relationship between humans and apes and the "human-like qualities of our ancestors, the early hominines.
Darwin noted the characteristics that make humans special in "Descent of Man" and felt that it was inevitable that natural selection would lead to the eventual emergence of humans once the earliest forebear became established.

At the beginning of the twentieth century there was extensive (and sometimes acrimonious) debate in anthropological circles about the changes that occurred as humans evolved from apes. Into this debate, in 1908, came the Piltdown skull, which suggested that the brain had led the way, that the first human was much older than expected and - the first human was an Englishman, a toolmaker who even had a primitive cricket bat.

View the audio visual sequence and listen to an account of the Piltdown man forgery. Remember as you listen to this that although the fraud itself is a fascinating story, it is the insight that you are given into the thinking of the time that you are most interested in.

Following exposure of the Piltdown fraud, new discoveries of hominine fossils and the view that culture was the dominant theme for human evolution, led to Loring Brace and Milford Wolpoff's single species hypothesis. More fossil discoveries in the 1970's led to the collapse of the hypothesis and it is important to understand the relevant evidence.

Objectives
3.1 Explain how the intellectual climate during the early twentieth century influenced eminent anthropologists to accept the Piltdown skull as a genuine fossil of a hominine intermediate between an ape and a human.
3.2 Outline the single species hypothesis and explain what led to its collapse.

Guided exercise 3.1 (Objective 3.2)
Bruce and Wolpoff's single species hypothesis collapsed in the 1970's in the face of overwhelming fossil evidence. Search the filing cabinet for fossils that provide evidence that refutes the single species hypothesis. There is no need to spend time studying the features of the skulls at this early stage of the course. Write a brief explanation of how you can use your chosen examples to refute the single species hypothesis. The use of specific lines of evidence to support or refute hypotheses is an important skill for S292.
4 stages are required to answer this question:
i) Explain the single species hypothesis.
Answer: The single species hypothesis states that only one species of hominine existed at any one time. Evolution proceeded by steady improvements up a single ladder. The rationale was that two species with similar adaptations cannot co-exist in the same environment, the principle of competitive exclusion.

ii) What evidence would cast doubt on the single species hypothesis?

Answer: If two or more species of hominine were shown to have co-existed this would refute the single species hypothesis.

iii) How can the filing cabinet be used to find the appropriate information?

Answer: Search through the cards in the australopithecine and Homo sections for examples of extinct species of hominines that were co-existing; you should find examples that were co-existing in the same area at the same time.

iv) Summarise you findings, explaining how they provide evidence against the single species hypothesis.
Answer: i) Fossils of Australopithecus garhi, dated at 2.5 mya were found at Afar, Ethiopia. The specimen of A.aethiopicus in the filing cabinet, dated at 2.5 mya was found at West Lake Turkana. Therefore around 2.5 mya, at least two hominine species were co-existing in the same part of Africa.
A fossil skull, Zinj, Australopithecus boisei, was found at Olduvai Gorge by Mary Leakey and is dated at 1.8.mya (Lewin, 1.75 mya, p 113). OH24, "Twiggy" is a skull of Homo habilis found at Olduvai Gorge and dated at 1.8 mya. There is a skull attributed to Homo rudolfensis in the filing cabinet, found at Koobi Fora, Kenya and dated at 1.9.mya.
The picture emerging from the evidence in the filing cabinet is that different hominine species were co-existing in Africa; 2.5 mya Australopithecus garhi and Australopithecus aethiopicus were co-existing. Around 1.8 mya, Australopithecus boisei was co-existing with at least two species of Homo.
The dates and locations of finds described in the filing cabinet indicate that different hominine species were co-existing thereby refuting the single species hypothesis.

Unit 4 Modern evolutionary theory
Unit 4 is an important foundation unit, because hominine and human evolution are described in later units in the context of modern evolutionary theory. Darwin's theory of natural selection and Mendelian genetics are explained in outline. The concepts of micro- and macroevolution are explained and the modern synthesis of evolution is derived.

The modern synthesis of Darwinism incorporates the principles of genetics and the principle of phyletic gradualism, whereby evolution proceeds gradually with accumulation of small changes over long periods. Niles Eldridge and Steven Jay Gould argued that the lack of transitional forms indicates that species remain static for long periods and then may change suddenly over a few thousand years - this is punctuated equilibrium.
If you are not familiar with Darwin's theory of evolution by natural selection, or Mendelian genetics, see the extracts from the science foundation course, S102 in the Downloads section.

Objectives
4.1 Describe the principles of natural selection as put forward by Darwin.
4.2 Discuss how modern evolutionary theory incorporates the sciences of genetics and population genetics.
4.3 Distinguish between microevolution and macroevolution.
4.4 Describe the concepts of evolutionary trends and adaptive radiation in the context of human evolution.

Guided exercise 4.1 (Objectives 4.1, 4.3, 4.4)
It is important to be able to apply modern evolutionary theory to human evolution. This guided exercise offers practice in using and understanding some of the terms.
Outline the sequence of events in the cartoon on page 7 as a scientific account based on the principles of Darwin's theory of evolution by natural selection. Begin with the hypothetical late Miocene ape, Mightopithecus, a species that lived in trees but spent some time on the ground. Write no more than 200 words and include at least five of the following terms in your answer: variation; mutation; natural selection; adaptation; traits; survival of the fittest; differential reproductive success; macroevolution; speciation.
i) Use the glossary to check the meanings of the highlighted terms.
ii) Look at the cartoon and try to ignore its jokey style! Starting at the left of the image you see Mightopithecus in the trees, but a bit further to the right, the apes are on the ground in an open environment. Unit 2 explains that climate change resulted in shrinkage of the forests. So you could write:
"Mightopithecus lived in the vast tropical forest covering Africa during the Miocene. Climate change altered the environment to open savannah with patches of forest and scrub".
iii) The cartoon shows the apes descending from the trees, running about and knuckle walking on the ground. The apes resemble chimpanzees. Modern evolutionary theory tells us that alleles (variants) of genes in individuals derive from mutations, which are spontaneous heritable changes in DNA. Mutations that confer advantages to individual Mightopithecus living in an open environment e.g. improved ability to walk on 2 legs, would enable those individuals to survive to breed. This is natural selection, in which individuals having mutations that improve their prospects of survival are more likely to survive to produce offspring, which themselves would have the mutation. Mutations improving the ability of apes to walk on 2 legs, provide adaptations for life on the ground. So you could write:
"Individuals in the forest-dwelling Mightopithecus population showed genetic variation. Those individuals having mutations relating to traits that increased efficiency of bipedalism were advantaged in the open environment, being more effective at finding food and avoiding predators, thereby increasing their reproductive success. This is natural selection operating by survival of the fittest. Individuals having adaptations that improved their survival chances in an open habitat were more likely to survive to breed".
iv) In the cartoon, the apes on the ground look different from those that are in the trees. Eventually the differences in the genes of the apes living in the remaining forest and those living in the open savannah become so great that the two populations could no longer interbreed - a new species now existed. Further to the right, Homo holding clubs and spears look different to the apes, indicating another new species. You need to interpreting this scenario in terms of the modern evolutionary theory:
"Genetic differences between the populations adapted to forest and the savannah eventually became so great that the two populations could no longer interbreed, resulting in speciation, the emergence of new species".
v) Further to the right, the enlarged skull of Homo is depicted indicating increased encephalization in Homo - brain size is determined by genes, the principles of natural selection can be applied to increased encephalization. The cartoon hints that Homo is an effective hunter and is a social creature and has technological skills.
" Natural selection promoted increased encephalization, and eventually emergence of Homo. Advantages of increased encaphalization include the ability to co-operate with others for improved hunting and avoidance of predators. For Homo living in groups, co-operation and culture, e.g. ritual, cave painting, social interaction, link to differential reproductive success. Technology played a part as ability to make and use stone tools increased hunting efficiency. Advantages of encephalization also link to increasingly complex technology. Large-scale migrations of Homo resulted in colonization of most of the planet".

Unit 5 Physical context of evolution
The physical context, geography and climate, influences the types of species that can thrive in particular regions of the world according to their adaptations.

Darwin focused on biotic interactions but appreciated that the physical environment plays a part in enhancing competition. The modern synthesis of evolution assumes that evolution continues even in the absence of changes in the physical environment; this is Leigh van Halen's (University of Chicago) red queen hypothesis. Allopatric speciation, the major mechanism of speciation, requires populations to be isolated - changes in the physical environment can isolate populations.

Plate tectonics provides an all-encompassing explanation for observations on the earth's surface that indicate continental drift e.g. South America and Africa drifted apart >60 million years ago leading to divergence of Old and New world monkeys.

Climate cycles and climate change also influence ecosystems and species. Elisabeth Vrba's (Yale University) habitat hypothesis states that species' responses to climate change are the main engine of evolutionary change.
Extract 8, in the Downloads section, discusses the divisions of geological time and the geological timescale.

Objectives
5.1 Describe the influence of plate tectonics on evolution, quoting examples.
5.2 Outline the major climate cycles that affect species: Milankovitch cycles and cooling episodes.
5.3 Describe species' responses to changes in climate.
5.4 Explain Elisabeth Vrba's habitat hypothesis.

SAQ 5.1 (Objectives 5.1, 5.2, 5.4)
Using the diagram on p. 22 and beginning with a hypothetical hominoid, Mightopithecus, living in tropical forest 20 million years ago, describe in no more than 150 words, how allopatric speciation could lead to evolution of a 'bushy' evolutionary tree for hominoids similar in structure to that drawn for horses on p. 19. Include the following terms in your answer: tectonic plate margin, or a variant of this term e.g.plate tectonics, tectonic processes; uplift; natural selection; allopatric speciation.

Unit 6 Extinction and patterns of evolution
Unit 6 explores the second link between evolution and the physical context of life, that of physical changes initiating mass extinction events.

About 30 billion species have evolved since the Cambrian explosion half a billion years ago, but only 30 million species exist today. Darwin's view of evolution by gradual progression contrasted with Cuvier's view of catastrophism, based on mass extinctions initiating new waves of emergence of new species.

Cuvier's idea of catastrophism was discredited by Lyell's interpretation of geological processes, uniformitarianism. It did not take long for paleontologists to realise that evidence of sporadic mass extinctions in the fossil sequence could not be ignored (chart, Lewin, p 26). Unit 6 speculates about possible causes of the 5 major extinction events and about why certain groups survived the mass extinctions, to become the dominant groups subsequently. Homo sapiens evolved from survivors of the 5 massive extinction events and at least 20 other biotic crises.

Objectives
6.1 Outline Cuvier's theory of catastrophism, put forward in the late 18th century, and explain how this fitted in with new evidence of major extinctions at the time.
6.2 Explain Lyell's theory of uniformitarianism and how ultimately, it was realized that both mass extinction and uniformitarianism are part of the pattern of evolution.
6.3 Suggest the causes of mass extinctions and quote one line of evidence that such mass extinctions have occurred.
6.4 Outline the response of surviving species to mass extinctions.

Guided exercise 6.1 (Objectives 6.2-6.3)
When Lyell put forward his theory of uniformitarianism in the 1830's he argued against catastrophism and mass extinctions. What arguments would you use today to demonstrate that mass extinctions did indeed occur? Does the existence of mass extinctions provide an argument against the principle of uniformitarianism? To answer this question, you need to draw on lines of evidence to support your arguments. The stages in the argument are as follows:
i) First write down what your argument is:
Mass extinctions do occur.
ii) State the evidence that supports your argument:

The fossil record provides clear evidence of mass extinctions, in that at certain points, many species suddenly disappear from the fossil record. One of the "Big Five" mass extinctions, the end-Cretaceous event, resulted in extinction of the dinosaurs, marked by their abrupt disappearance from the fossil record. The presence of iridium in the Cretaceous/Tertiary boundary suggests that the mass extinction of the dinosaurs was caused by the impact of an asteroid. Evidence of a crater has been found.
iii) Answer the question: Does the existence of mass extinctions provide an argument against the principle of uniformitarianism?
The existence of mass extinctions does not refute the principle of uniformitarianism. Mass extinctions occur within the background of normal geological processes, such as deposition of sediments, erosion, earthquakes, and volcanism.

SAQ 6.1 (Objectives 6.2-6.4)
For each of the statements below, state whether true or false, giving the reason for your answer:
(a) At the end of the Cretaceous extinction mammals evolved in order to colonize the ecological niches left vacant by the absence of the dinosaurs.
(b) Mammals survived the Cretaceous extinction because they were better adapted than the dinosaurs.
(c) A clade having few species that are widespread geographically has a better chance of surviving a mass extinction event than a clade of many species occupying a restricted area, say a lake or land-locked sea.
(d) Adaptive radiation of mammal species surviving the end-Cretaceous extinction resulted in increasing diversity as mammals occupied niches previously occupied by dinosaurs and other reptiles.

Part Two: Background to human evolution

Unit 7 Dating methods
Working out an accurate time scale is essential for obtaining information on the pattern of evolution of early hominines. Direct dating of most stone tools and ancient fossils is impossible.

C14 dating and electron spin resonance can be applied to teeth or young fossils. Relative dating techniques are based on what is known about the dating of the stratigraphic column. Most absolute dating techniques relate to radioactive decay in specific minerals associated with fossil remains e.g. radiopotassium/argon dating. Thermoluminescence and electron spin resonance dating techniques are relatively new and measure dates between a few thousand and 1 million years ago, dates particularly useful for paleoanthropology.

Many important archeological sites e.g.those in South Africa, lack material suitable for dating or have material embedded in too-complicated stratigraphy.

You do not need to understand the details of these complex techniques; understanding of the basic principles is adequate.

Objectives
7.1 Outline the following relative dating techniques: faunal correlation and paleomagnetism and appreciate the contexts in which they can be used.
7.2 Outline the following absolute dating techniques: potassium/argon dating, fission track, carbon-14 and uranium series, and appreciate the contexts in which they can be used.
7.3 Outline the following two new techniques of dating: thermoluminescence and electron spin resonance and appreciate their importance for paleoanthropology.

SAQ 7.1 (Objective 7.2)
Why can radiopotassium dating only be used to date volcanic rocks? Why is it difficult to date sedimentary rocks by means of radiopotassium dating?

Guided exercise 7.1 (Objectives 7.2, 7.3)
To answer these questions, you will need to put together information from Unit 7 with information from News online and Web Links sections. The first stage in writing the answer is to read the information available. Select the relevant information, and present it in a logical sequence, to address the questions asked.

i) The oldest human fossils discovered in Australia were found at Lake Mungo (S292 web site; Lewin, p 212) and dated at 25 000 BP. Search the S292 web site to discover what technique was first used to obtain this date and outline your findings.

Answer:
Click on Web Links and then on "Mungo man". This site describes the discovery in 1968 by Jim Bowler of the Lake Mungo 1 cremation, containing the fossil remains of Mungo man. Radiocarbon dating of bone fragments resulted in a date of 19 030 ±1410 years for bone apatite and 24 700 ±1270 years for bone collagen of Mungo man. A date of 26 250 years was obtained by radiocarbon dating of a hearth.

ii) Search the S292 web site to find which techniques were used for re-dating the Mungo man fossils. Name the techniques used, and quote the new dates for Mungo man. Explain why the techniques used for the re-dating are considered more reliable than those used for the original dating.

Answer:
*Alan Thorne re-dated the Mungo man fossils as 60 000 years old, using three new and reportedly more accurate techniques: electron spin resonance, uranium dating and optically stimulated luminescence. Use of uranium series dates to just under 500 000 years ago. The techniques are believed to be accurate because the measurements made relate to the number of electrons trapped in a mineral since it was last exposed to heat or light energy. The electrons are trapped inside the mineral until it is exposed to heat or light; the electrons do not "decay".
Radioactive carbon, C-14, has a relatively short half-life, hence it has limited applications in paleoanthropology. Contamination is a problem as just a small amount of fresh carbon can give an erroneously young age for the material.
References
http://www.archaeologytoday.net/0599toc/5randn2-australian.shtml

Unit 8 Systematics: morphological and molecular
Classification of living organisms brings order to the study of diversity of life and enables study of relationships between groups of animals. Linnaeaus based his hierarchical classification system on anatomical similarities only, but Darwin was keen that classification should reflect phylogeny.

Currently there are three schools of classification of living organisms. "Phenetics" focuses on anatomical similarities, which are linked to adaptation, but do not necessarily reflect phylogeny (see example, Lewin, page 43). "Cladistics" selects characters that reflect genetic relatedness, to produce a classification system based on the path that evolution followed. As cladistic practice is relevant to hominine classification, you will need to familiarise yourself with cladistic terminology. "Evolutionary systematics", combines adaptation and relatedness.

Genetic evidence has affected views on classification of the Hominoidea. The concept of a molecular evolutionary clock is used for determining the branching order of related species using genetic data and calculated dates of when lineages diverged. However, not all regions of DNA are equally susceptible to change so there are potential differences between the species tree and the gene tree.

Objectives
8.1 Outline the Linnaean system of classification.
8.2 Summarize the philosophies of the three major schools of classification and systematics: phenetics, cladistics and evolutionary systematics.
8.3 Explain the concepts of analogy and homology and show how homologous characters can be described as primitive and derived.
8.4 Describe the concept of molecular systematics and discuss its limitations.
8.5 Explain the advantages of molecular phyogenetics for reconstructing the evolution of humans.

SAQ 8.1 (Objectives 8.1-8.2)
Which of the three major schools of classification is closest to the Linnaean system? Write no more than 25 words.
SAQ 8.2 (Objectives 8.2, 8.3)
Give two examples of analogy. Explain why analogous characters cannot be used to reconstruct phylogenies. Write no more than 150 words.

Unit 9 Science of burial
Taphonomy, the study of processes by which bones become fossilised, suggests caution in interpretation of accumulations of fossil bones of hominoids and other animals. Such accumulations may result from sorting processes caused by water flow in rivers rather than hunting and scavenging activity of ancient hominines.

Many accumulations of bones of hominines and other animals in the breccia of caves in S Africa are likely to be remains of carnivores' meals rather than leftovers of ancient hunter-gatherer home bases.

However the cut marks on some of the bones at Olduvai Gorge, Tanzania, provide evidence that at least at this site, hominines appear to have been eating meat. Nevertheless caution is required, as Behrensmeyer and colleagues (Smithsonian Institution) showed that trampling of bones in sandy sediments causes abrasions similar to cut marks made by stone tools*. Sandra Olsen and Pat Shipman (University of Pennsylvania) argue that it is possible to distinguish cut marks from the effects of trampling.

See the News article "New species found" which shows an image of smashed antelope bone found in association with fossils of Australopithecus garhi.

Objectives
9.1 Explain why intact fossilized skeletons of fossil hominoids are rarely found.
9.2 Describe how bones can be buried and later exposed and even sorted by water action.
9.3 Outline explanations for the presence of fossil animal and hominine bones in the breccia of caves in South Africa
9.4 Explain the problems of identifying marks on fossil bones, describing two examples: marks on bones found at Olduvai; effects of weathering and abrasions from sand grains.

SAQ 9.1
Classify the following as true, uncertain or false, and provide a brief explanation for your view.:
(a) The finding of assemblies of broken bones and chipped stones dated at about 2 million years shows that early Homo was a hunter-gatherer subsisting mainly by hunting animals and cutting up carcasses by means of stone tools.
(b) Cut marks found on a few of the fossil bones at Olduvai Gorge were caused by hominines using sharp stone tools.
(c) Assemblies of broken animal bones and chipped stones dated at almost 2 million years old have been found at Olduvai Gorge; the finding of Homo habilis skeletal remains at Olduvai dated at 1.85-1.75 million years old indicates a connection between Homo and the stones and bones.
(d) The only way cut marks and abrasions can be made on long bones of large animals is by means of tools such as axes and choppers.
(e) Accumulations of fossil animal bones and chipped stones are the remains of ancient hunter-gatherer home bases.
SAQ 9.2
Access the S292 website; click on "News online" and "New species found" Examine the image of one of the smashed animal bones found with the Australopithecus garhi fossils. What evidence supports the view that the bone was deliberately smashed by a simple stone tool? What other possible interpretations are there for the damage to the bone? Write up to 100 words.

Unit 10 Primate heritage
Homo sapiens, unlike other primate species, occupies a wide range of habitats and tolerates extreme climates. There are about 200 living species of primate; 80% of them live in rainforest; the remainder live in other types of tropical habitat including savannah, semi-desert scrub, woodland and scrubland.

Robert Martin (Anthropological Institute, Zurich) wrote a detailed definition of a primate, a key point being that primate brains are larger for their body size compared with those in other mammalian orders. The marked encephalisation of Homo sapiens is an extension of this trait.

Unit 10 looks at theories explaining the origin of primates, including Grafton Smith and Wood Jones' arboreal hypothesis, and Matt Cartmill's (Duke University) visual predation hypothesis. The overall pattern of primate evolution is unclear, with 2 major groups identified, omomyids and adapids, dating back to 50 mya. There is evidence that modern tarsiers and anthropoids shared a common ancestor. A fossil omomyid, Eosimas, dated at 50 million years ago, found at Shanhuang, China, has a dental formula close to what would be expected of an ancestral anthropoid.

Objectives
10.1 Describe the diversity of the primates and their classification into four main groups: prosimians; New World monkeys; Old World monkeys; hominoids.
10.2 Interpret classification schemes for the order Primates such as that on p. 55.
10.3 List the key components of Robert Martin's definition of a primate.
10.4 Describe two theories of the origin of the primate adaptation; the arboreal hypothesis and the visual predation hypothesis.
10.5 Summarize the three views of primate evolution by interpretation of the 3 schemes provided on page 54.
10.6 Explain the significance of the finding of fossil Eosimias, which indicates the origin of anthropoids at about 50 million years ago.

SAQ 10.1 (Objectives 10.2, 10.3)
With so much information available in the field of human evolution it is important to be able to identify and summarise the salient points.
Summarize Robert Martin's definition of a primate as a list of bullet points, indicating for each whether it is one of the criteria we can use to define humans.
SAQ 10.2 (Objectives 10.4)
Outline the major differences between Grafton Elliot Smith's and Frederic Wood Jones arboreal hypothesis and Matt Cartmill's visual predation hypothesis for the origin of primates. What arguments did Cartmill use to dismiss the arboreal hypothesis? Outline the arguments for what is regarded as the most reasonable view of the origin of the primate adaptation. Write no more than 150 words.

Part Three Humans as animals

Unit 11 Bodies, size and shape
There are two 'rules' linking body form to adaptation to climate:
Bergmann's rule states that in geographically widespread species, populations in the warmest parts of the range will be smaller bodied than those in colder parts of the range.

Allen's rule states that populations of a geographically widespread species living in warm regions will have longer extremities than those living in cold regions.

The rules apply to living human populations; examples include Nilotic people, Eskimos and Mbuti pygmies. Anthropologists apply these rules to extinct hominines e.g. Lucy, Australopithecus afarensis and the Turkana boy, Homo ergaster.

Explaining the loss of robusticity in early anatomically modern humans dating from ~30 000 to 5 000 years ago is more complicated. Loring Brace, (University of Michigan) suggests loss of robusticity was related to energy-saving technological inventions. Robert Foley, (Cambridge University), proposed shortage of food at an early stage of agriculture as a selective pressure. However loss of robusticity also occurred in hunter gatherer peoples and in non-human animals and has been attributed to the global increase in temperature at the end of the Pleistocene.

Objectives
11.1 Apply Bergmann's and Allen's rules to (a) human populations living today, and (b) to Lucy and the Turkana boy.
11.2 Explain changes in robusticity of human populations to their way of life in terms of Darwin's theory of natural selection.
11.3 Explain how the decline in robusticity of human populations from about 10 000-5 000 years ago may relate to global warming from the end of the Pleistocene.

SAQ 11.1 (Objective 11.1)
Find the "Ancestral lines" site on the S292 website. Using information from the site and also information about the Turkana boy in Unit 11, compare the body proportions of Neanderthals and Homo ergaster and as far as possible, apply Bergmann's and Allen's rules.
This question asks for extrapolation of Allen's and Bergmann's rules to extinct Homo species using what you know about body proportions in living peoples.
There is detailed information about the Turkana boy in Unit 11 but you need to search the Ancestral Llines website for detailed information about Neanderthals.

Unit 12 Bodies, brains and energy
Unit 12 looks at the effects of size of bodies and brains on life history variables and behaviourial ecology.

Population biologists distinguish between two extreme life history strategies (Table 12.1). Species with a high potential reproductive output are described as r- selected; species that produce few offspring and tend to maintain a stable population size are K-selected.

Within the primates there is a wide range of life history patterns, ranging from extreme K-selection in Homo sapiens to r-selection in the tiny mouse lemur. Body and brain size link to life history factors e.g. small species tend to live "fast" lives but large species live "slow" lives.

Australopithecus afarensis, an early hominine, was a large animal, the females being ~1 metre tall, the males, 1.7 metres tall. Homo ergaster was about 1.8 metres tall. For both species, it can be suggested that they were large hominines exploiting a stable food supply and living a slow life in terms of life history variables, with the huge increase in brain size related to secondary altriciality.

Objectives
12.1 Define K-selection and r-selection and apply the principles to extinct and living primate species.

12.2 Discuss the relationship between body size and values for various life history variables: age at maturity, length of gestation, litter size, duration of lactation, interbirth period and lifespan; effectively the differences between animals living 'fast' lives and those living 'slow' lives.
12.3 Outline the relationship between basal energy demand and body mass: Kleiber's curve.
12.4 Link precociality and altriciality with life-history factors.
12.5 Explain in outline how, using what is known about body proportions and life-history factors in living species, predictions can be made for early hominine species.

SAQ 12.1 (Objectives 12.1, 12.2, 12.4 and 12.5)
Eosimias, a fossil primate discovered in China, is dated at 45-42 mya (see image on web site). Estimated body mass was 15 - 100g; fossil foot bones indicate that the animal, walked about on flat surfaces rather than clinging to branches. What predictions, if any, can be made for life history strategies in Eosimias?
http://news.bbc.co.uk/hi/english/sci/tech/newsid_678000/678458.stm
http://abcnews.go.com/sections/science/DailyNews/fossil000315.html

Unit 13 Bodies, behaviour and social structure
Most living primate species are social animals living in groups of 2-200 individuals. Richard Wrangham (University of Michigan) suggests that ecological pressures including defence against predators and food distribution relate to species differences in social behaviour (see summary diagrams in Lewin pp 70-71).

The pattern of social organisation is linked to relative body sizes of males and females. Natural selection in species in which male-to-male competition occurs is likely to result in increased body size e.g. gorillas. However, Robert Martin (Institute of Anthropology, Zurich) noted that sexual dimorphism in body size may relate to natural selection for earlier maturity in breeding females leading to smaller body size.

Large canine teeth in males are characteristic of polygynous social structures, e.g. baboon. Information gleaned from the anatomy and social structure of primate species living today is useful for making predictions about social organisation in extinct hominines.

Objectives
13.1 Describe in outline the social organization of the following apes: gibbon; orangutan; chimpanzee; gorilla.
13.2 Discuss relative benefits and disadvantages of group-living for primates, e.g. relating to access to food.
13.3 Explain how distribution of food within an environment relates to the social structure of a group of primates using gibbon, orangutan, chimpanzee gorilla and baboon as examples.
13.4 Discuss the consequences of social organization with regard to anatomical features such as sexual dimorphism in body size and tooth size.

SAQ 13.1 (Objectives 13.1-13.4)
Adult orangutans are highly territorial. Individuals learn which trees in their territory bear nutritious fruits and nuts and visit these trees periodically to feed. Gorillas eat leaves, an abundant but not nutritious food source. Outline Wrangham's model, which explains how the social structure of the orangutan and the gorilla link to distribution of their food within the environment and to sexual dimorphism in body size.

Unit 14 Nonhuman models of early hominines
Each species of living ape has a unique social organisation- this probably applied to early hominines. Nevertheless it is useful to use modern primates to model the lives of extinct species. Three approaches to models are summarised in Lewin, Table 14.1:
-Identifying living species that seem to match some basic hominine characteristics e.g. baboon, chimpanzee and bonobo.
-Richard Wrangham (University of Michigan) used phylogenetic comparisons to identify basic shared behavioural characteristics among humans and African apes.
-Reconstruction of social organisation from first principles of behavioural ecology was developed by Richard Foley and Phyllis Lee (University of Cambridge).

Foley and Lee suggest a chimpanzee-like social structure for early australopithecines based on what is known about the prevailing African climate at the time. However Australopithecus afarensis shows extreme sexual dimorphism in body size on a scale similar to that observed in orangutans. Unit 14 ends by discussing the evidence that Homo ergaster/erectus males co-operated within their groups in order to cope with inter-group competition for territory and resources.

Objectives
14.1 Outline the three approaches to non-human models of early hominine: primate models, phylogenetic models and behavioural ecology models and explain the findings.
14.2 Explain why behavioural ecology models are the most useful for reconstructing the possible social organization of early hominines.
14.3 Explain the rationale behind Foley and Lee's view that the social structure in early australopithecines consisted of mixed sex groups with males linked by kinship and show how this view conflicts with evidence from fossil remains of A. afarensis.
14.4 Outline Foley and Lee's views on the possible relationship between meat-eating and social structure in Homo ergaster/erectus.
14.5 Discuss the implications of sexual dimorphism in body size in modern Homo sapiens with regard to male-to-male competition in the recent past.

SAQ 14.1 (Objectives 14.2, 14.4, 14.4)
Classify the following statements as true or false, explaining your answer briefly:
(a) Foley and Lee suggest that the most likely social structure in ancestral hominines was gorilla-like. Therefore the ancestral hominines must have resembled gorillas.
(b) Studying social carnivores such as lions is helpful in making predictions about the behavioural ecology of early hominines because of their homologous behaviour while hunting.
(c) The dimorphism in body size in male and female Australopithecus afarensis indicates extreme competition between males for access to females.
(d) Fossil evidence indicates that the social structure of Homo ergaster/erectus centred on the nuclear family.
SAQ 14.2 (Objectives 14.4, 14.5)
Click on Ancestral Lines in the S292 website and then click on Homo ergaster and also Homo erectus to find information about average height and weight for male and female Homo ergaster and erectus. Look in the News Online item, "The Dmanisi skulls" in the S292 website for details of tooth structure in Homo ergaster. There are also images of the skulls of Homo ergaster/erectus in the filing cabinet.
What can you deduce about the possible social structure in Homo ergaster/erectus from body size differences and also differences in teeth between male and female? Is there any evidence for a social structure like that of the gorilla?

Part Four: Hominine beginnings

Unit 15 Ape and human relations: morphological and molecular views
Unit 15 explores evolutionary relationships between living hominoids in terms of morphology and molecular studies. Comparative anatomy studies indicate that the chimpanzee, is the closest relative of humans; the orang-utan is more distant.

The concept of a molecular clock developed from use of molecular evidence to work out phlyogenetic pathways. Allen Wilson and Vincent Sarich's molecular clock indicated that African apes and humans diverged 5 million years ago. Sequencing of mitochondrial and nuclear DNA, electrophoresis of proteins, also support the link between African apes and humans indicating a divergence time of 5-6 million years ago.

Molecular studies indicate gene trees which are not always the same as species trees (pp 83-84). The majority morphological view derives different cladograms from those derived by the majority molecular view (p 84).

There is argument about the appearance of the common ancestor of African apes and humans, in particular about whether it was chimp-like. Disputes about classification of the Hominoidea hinge on whether Morris Goodman's classification placing both humans and African apes within the Hominidae is valid.

Objectives
15.1 Outline how comparative anatomy of living apes, modern humans and extinct hominoids is interpreted to indicate evolutionary relationships between the groups.
15.2 Outline how molecular studies have indicated that the genetic distance between humans and African apes implies that they diverged about 5 million years ago.
15.3 Understand the significance of how molecular evidence supports a species tree with two divergence points, first separation of the gorilla, followed later by a human/chimpanzee split.
15.4 Appreciate that gene polymorphism in an ancestral species followed by differential sorting of variants can lead to incorrect conclusions about timing of divergence and relationships between species.
15.5 Describe the possible anatomical features of the common ancestor of apes and humans.
15.6 Interpret alternative classification schemes for hominoids.

SKULL STUDIO: Work through the skull studio exercise, comparing Homo sapiens skull with Zinj.

SAQ 15.1 (Objectives 15.1; 15.5)
Compare the features of the skull of the chimpanzee and that of Homo sapiens, summarising them in a table of your own design. For a view of the chimpanzee skull, available on the S292 web site, click on "Site reviews" and then on "Ancestral lines". Click on the chimpanzee option. There is a good image of a chimpanzee skull; line drawings of the chimpanzee skull and jaws can be found in Lewin, pages 100, 101.
SAQ 15.2 (Objectives 15.6)
Which of the three classification schemes drawn in Table 15.1 reflects the close evolutionary relationship between chimpanzees and humans? What arguments have been put forward against this scheme?

Unit 16 Origin of the Hominoidea
The Hominoidea are classified in the infraorder Catarrhini. Early fossil catarrhines are found in North Africa and Eurasia, whereas modern Old World monkeys and apes are found in the forests of sub-Saharan Africa and southeast Asia. The early fossil record for catarrhines indicates that apes were more abundant and diverse than monkeys, but living Old world monkeys are more abundant and diverse than apes.

Fossil remains of early apes show characters unknown in living apes so it is likely the early forms had different behaviours to species living today. You are not expected to remember all of their names. Eosimias is important, considered to resemble a "basal" anthropoid. Proconsul, which has a mix of ape and monkey features in its postcranial skeleton, is an important fossil hominoid dated at around 22 million years. Fossil remains of Dryopithecus, an important later hominoid, include a partial postcranial skeleton showing similarities to apes, found in Spain, dated at 9.5 million years. A salient point is that the fossil record indicates a successful hominoid radiation having many diverse branches, forming a bushy tree.

Index card - View Proconsul skull in filing cabinet.

Objectives
16.1 Explain how the fossil record of catarrhines indicates that extinct catarrhines were very different from those living today, in terms of geographical distribution, relative numbers of apes to Old World monkeys, and morphology.
16.2 Outline the general features of early fossil anthropoids, dating from 50 to 31 million years ago.
16.3 Outline what is known of the features of the earliest hominoids, in particular Proconsul, dating from about 26-18 million years ago.
16.4 Explain how fossil evidence for the diversity of the later hominoids, supports the widespread adaptive radiation of the group .

SAQ 16.1(Objective 16.3)
View the skull and teeth of Proconsul in the 2 images provided in the index cards. Add the features you observe to the table you prepared for SAQ 15.1. Highlight those features of Proconsul that make it ape-like.

Unit 17 Origin of bipedalism
The basic hominoid adaptation comprises: bipedalism; reduction of anterior teeth with expansion of cheek teeth; elaboration of material culture; increased brain size. Fossil evidence indicates that bipedalism was the earliest hominine adaptation. The list of anatomical adaptations (p94) linked to human bipedalism is important, providing a basis for comparison with fossil hominine bones.

Ideas on the origin of bipedalism link to its selective advantages. Two hypotheses, 'Woman the gatherer' and 'Man the provisioner', promote the greater ease in carrying food and objects for a bipedal hominine. The earliest hominines may have evolved in heavily wooded habitats, not open savannah. Karen Steudel (University of Wisconsin) highlighted evidence that bipedal locomotion would not have been energetically efficient in hominines having arboreal adaptations.

Peter Rodman and Henry McHenry (University of California at Davis) suggested a parsimonious explanation for the selective advantage of bipedalism, a change in distribution of dietary resources. Kevin Hunt (Indiana University) used field observations of gorillas and chimpanzees to support hypotheses linking the origin of bipedalism to feeding efficiency.

Objectives
17.1 Outline the striding gait of human bipedalism from a set of images e.g. p94.
17.2 List the anatomical adaptations that underlie human bipedalism.
17.3 Outline the features of bipedalism that confer selective advantage.
17.4 Suggest the ecological and behavioural contexts of the origin of bipedalism, in particular the 'Woman the gatherer' and 'Man the provisioner' models.
17.5 Discuss the advantages of bipedalism relating to energy efficiency during foraging and feeding.

SAQ 17.1 (Objective 17.5)
Watch the video clip of the chimpanzee gathering fruit (S292 CD-ROM). Does the behaviour of the chimp support Kevin Hunt's view that bipedal behaviour links to stationary feeding rather than to locomotion? Write no more than 75 words.

Unit 18 Jaws and teeth
The commonest hominoid fossils are jaws and teeth, preserved because they are denser and tougher than the rest of the skeleton. Teeth and jaws provide useful information about diet and behaviour of fossil hominoids, but their use in interpretation of evolutionary relationships requires caution because they are subject to convergent evolution.

A clear evolutionary trend in the structure of the primate jaw and face is front-to-back shortening and deepening from top to bottom. Evolutionary trends in dentition comprise an increase in cheek tooth size and decrease in anterior tooth size from ape to Australopithecus subsequently reversed in Homo (Lewin, diagram, page 99).

The pattern and timing of tooth eruption in apes and humans is distinctive. Relative thickness and wear patterns of tooth enamel on cheek teeth are characteristic for apes and humans and provide evidence for diet. The earliest hominines possessed thin enamel; later hominines, like humans, have thick tooth enamel, presumably an adaptation for processing tough plant foods. Early hominines' tooth wear patterns suggest a fruit diet. Homo erectus teeth have sharply pitted and scratched enamel indicating meat eating.

Go to the Virtual Office to view examples of skulls of australopithecines and Homo species, focusing on teeth.

Objectives
18.1 Describe the basic anatomy of ape, Australopithecus and Homo skulls and teeth, highlighting the major differences.
18.2 Compare eruption patterns of permanent teeth in modern apes and humans and appreciate that tooth eruption patterns were intermediate between human and ape in. Homo ergaster.
18.3 Discuss the importance of enamel thickness as a phylogenetic indicator.
18.4 Explain how toothwear patterns may indicate the diet of extinct hominines.

SAQ 18.1 (Objectives 18.1)
Skull and dentition of Australopithecus afarensis, an early hominine, is described as being intermediate between that of ape and human. Assess whether this is the case.

Unit 19 The earliest known hominines
Little is known about the complex early history of the hominine clade. Australopithecus afarensis was considered to be one of the earliest hominines - fossils dating 2.9-3.9 mya have been found in Ethiopia, Tanzania and Kenya. Unit 19 uses evidence from fossils of A. afarensis to make deductions about locomotion.

Owen Lovejoy interprets pelvic and lower limb structure of A. afarensis as indicating bipedal locomotion; Christine Tardieu and Brigitte Senut interpret limb structure as indicating arboreality. William Jungers, Jack Stern, and Randall Susman, (SUNY, Stony Brook) interpret the fossil evidence as indicating that A. afarensis was both bipedal and arboreal!

More recent finds of fossils older than A. afarensis include Ardipithecus ramidus, from Ethiopia, dated at 4.4 mya and Australopithecus anamensis, from Kanapoi, Kenya dated at 4.2 mya. Evidence from recent fossil finds supports the early origin of bipedalism and a bushy model for evolutionary relationships.

Studies of the paleoenvironments where hominine fossils have been found indicate a variety of habitats, both woodland and open grassland, information to be taken into account when discussing competing hypotheses for the origin of bipedalism.

View information on new finds of even earlier hominines in the filing cabinets of the Virtual Office, including Orrorin tugensis, (6 mya), Ardipithecus ramidus kadabba (6 mya), and Kenyanthropus platyops (3.5 mya)..
i) View News Online for items about "Millenium man", Orrorin tugenensis, a new fossil hominid found in Kapsomin, in the Tugen Hills, Kenya.
ii) View News Online for 2 items about a new species found in Kenya, named Kenyanthropus platyops. It is worthwhile reading the original Nature papers which are available in full on the news items. If you are short of time, the short summary paper written by Daniel Lieberman is a better option. A salient point is that Kenyanthropus platyops dated at 3.5 million years old, was co-existing with Australopithecus afarensis.

Objectives
19.1 Describe the main features of the anatomy of Australopithecus afarensis.
19.2 Draw conclusions about the locomotion and behaviour of Australopithecus afarensis based on the fossil evidence.
19.3 Explain how early hominine evolution involved adaptive radiation as indicated by discoveries of fossil hominines older than and contemporary with Australopithecus afarensis.
19.4 Link adaptive radiation of early hominines to the diversity of habitats they occupied.

SAQ 19.1 (Objectives 19.3, 19.4)
Fossil remains of Orrorin tugenensis ("Millenium man") were found in 2000. Give two reasons, with supporting evidence, why Orrorin is regarded as being an important and significant find. Search the S292 web site to find the answer. Write no more than 150 words.
http://www.humanevolution.f2s.com/tugenensis.html
This could be added to the S292 web site as this has good information on the evidence for bipedalism in the limb bones of Orrorin.

Part Five: The hominine adaptation

Unit 20 The australopithecines
View the black skull in the filing cabinets of the Virtual Office. The context for Unit 20 is that about 2-3 million years ago, a number of hominine species were co-existing in Africa. There were two groups of hominine: Homo species, large-brained with small cheek teeth; australopithecines, small brained with large cheek teeth, all of which are now extinct.

Fossils of australopithecines have been found in South and East Africa (see map on p114), with at least 8 species identified. There is evidence that australopithecines lived in bushland and woody savannah, feeding on fruits. Two 'types' of australopithecine are identified, robust and gracile. Graciles were regarded as ancestral to the robust forms- ranges of 3.5-2.5 million years were estimated for graciles and 2.0-1.0 million years for robust forms. However discovery of the robust black skull, KNM-WT 17 000 (Alan Walker,1985), upset this view as it is dated at 2.5 million years, and is as old as some gracile species.
S292 web site: i) View "news online", 1999 and find 3 items about Australopithecus garhi, an important find of a new species of australopithecine.

SKULL STUDIO: Work through the skull studio exercise, comparing Homo sapiens skull with Zinj.

Objectives
20.1 Summarize the fossil finds of australopithecines in Africa, noting that a number of different species have been identified; Australopithecus afarensis, A. robustus, A. boisei, A. africanus, A. aethiopicus and A. bahrelghazali.
20.2 Draw conclusions about the biology of australopithecines from the fossil evidence.
20.3 Outline the main features of australopithecine anatomy and, where possible, make links between anatomy and locomotion.
20.4 Discuss the possible relationships between robust and gracile australopithecines.
20.5 Access fossil and archaeological evidence discovered since the publication of Lewin's book, including Australopithecus garhi and evidence for tool use in Australopithecus robustus, and understand their significance.

SAQ 20.1 (Objectives 20.1, 20.3)
Describe what is known about the anatomy of Australopithecus robustus as a list of bullet points. You should focus on aspects of skull structure, tooth structure and chewing muscles. You will need to draw on information for the S292 web site as well as from Lewin.

Unit 21 Early Homo
A defining feature of early Homo is larger brain size,~640 cm3 ,compared to ~400 cm3 in australopithecines. The first finds of early Homo fossils, at Olduvai Gorge, Tanzania, were dated at 1.75 million years, and named as Homo habilis by Louis Leakey, John Napier and Phillip Tobias.

The naming of Homo habilis provoked many arguments between the 'lumper' and 'splitter' schools of classification because of the anatomical variation between fossils. Evidence from fossil finds during the 70's and 80's indicated the existence of two species of early Homo, one dating back earlier than 2 million years. Frederich Shrenk and Timothy Bromage (Hunter College, New York) described a specimen found in Malawi dated 2.3-2.5 million years old, which they named H. rudolfensis. There is a useful summary of the features of H. habilis and H. rudolfensis on p123.

Following Bernard Wood's proposal in 1992 that there were two co-existing species of early Homo, the existence of H. habilis and H. rudolfensis was widely accepted. Which of the two species gave rise to later Homo is the subject of argument.
View skull of Homo habilis in filing cabinets of the Virtual Office.
View skull of Kenyanthropus platyops and compare with images of Homo habilis and Homo rudolfensis skulls in Lewin, p 123.

Objectives
21.1 Explain the two different philosophies of classification, the 'lumpers' and the 'splitters' in the context of the discovery and naming of Homo habilis.
21.2 Describe how finds of fossil early Homo created puzzles, e.g. relating to the evolutionary relationship between Homo habilis and Homo ergaster.
21.3 Draw conclusions about the anatomy and biology of early Homo using fossil evidence.
21.4 Summarize the rationale for splitting fossils of early Homo into two species, H. habilis and H. rudolfensis*.

SAQ 21.1 (Objectives 21.3, 21.4)
Draw up a table summarizing comparisons in skull anatomy and biology between Australopithecus afarensis , Kenyanthropus platyops, Homo habilis and *Homo rudolfensis. Images of the skulls are available in Lewin and the S292 website.
* It has been suggested that this species should be named Kenyanthropus rudolfensis.

Unit 22 Hominine relations
There are two extremes of classification. 'Splitters' ruled in the first half of the 20th century with each tiny variation in structure in fossil hominines spawning a new species. In 1965, Elwyn Simons and David Pilbeam (Yale University) drastically reduced the number of genera and species initiating the 'lumping' philosophy of classification. In the 1960's and early '70s, lumping led to the 'single species hypothesis' (Unit 3).

Paleontologists look for anatomical features of fossils that are useful as phylogenetic indicators- there are problems in identifying homoplasies. There are three key questions in hominine phylogeny (Objective 22.3).

The technique of grouping features into functional complexes, e.g.heavy chewing, was used by Skelton and McHenry in their analysis of hominine phylogeny. Although the traits making up the heavy chewing complex are subject to homoplasy, Skelton and McHenry constructed a phylogeny in which Australopithecus ramidus is the most primitive early hominine, giving rise to Australopithecus anamensis and Australopithecus afarensis (forest of evolutionary trees, p128).

Objectives
22.1 Appreciate that 'lumping' and 'splitting' are two extreme views of classification and that neither is appropriate to be applied as a central philosophy of classification.
22.2 Understand that not all data from fossils can be used as phylogenetic indicator; features subject to homoplasy, e.g. teeth and jaws need careful interpretation.
22.3 Outline the three key questions in early hominine evolution:
-the relationship between Australopithecus afarensis to earlier and later hominines;
-the relationships amongst the robust australopithecines, A.aethiopicus, A. robustus and A. boisei;
-the origin of the genus Homo.
22.4 Outline Skelton and McHenry's cladistic analysis of cranial traits grouped into 5 functional complexes: heavy chewing (34 traits); anterior dentition (11 traits); basicranium flexion (11 traits); prognathism/orthognathism (8 traits); encephalization (3 traits). (note: number of traits does not add up to 77!)
22.5 Compare the hominine evolutionary tree derived by Skelton and McHenry's analysis with the other three trees outlined on p. 128.

SAQ 22.1 (Objectives 22.2-22.4)
Classify the following statements as true or false, giving reasons:
(a) 'Lumping' is the correct strategy for classifying fossil hominines because members of species living today show considerable variation in anatomy.
(b) Natural selection may result in evolution of similar dentition in species eating similar diets; therefore teeth and jaws are susceptible to homoplasy.
(c) Australopithecus afarensis , the earliest hominine, is the ancestor of Homo.
(d) Australopithecus afarensis is the founding species of the hominine clade.

Unit 23 Early tool technologies
Unit 23 explains how stone tool assemblages have been classified into 5 categories, modes I-V, defined by characteristic artifacts. Terminology of the archeological time periods links to first appearance of characteristic stone tools although there are geographic variations and some paradoxes.

Different terminologies are used to describe archaeological time periods in sub-Saharan Africa and Eurasia. The oldest stone tools, Oldowan technology, dated at 2.6 mya, were found in Ethiopia and Kenya. The salient point is that making Oldowan tools represents a technological revolution, requiring percussion knapping, a complex and skilled technique, that cannot be mastered by apes. Nicholas Toth's work demonstrated that Oldowan stone tools are effective implements for butchering meat.

Although the appearance of Oldowan technology co-incides with the first appearance of Homo 2.5 million years ago, the identity of the Oldowan toolmakers is disputed, with argument that robust australopithecines had the capacity to make stone tools* (Randall Susman, SUNY, Stony Brook).
*View "News online"
News items about Australopithecus garhi fossils associated with stones and smashed antelope bones suggest that these australopithecines were using stone tools 2.5.mya.
"Ape-man ate termites" Australopithecus robustus: used bone tools to fish for termites -there are good images of the tools.

Objectives
23.1 Tabulate the classification of stone tools into five categories or modes.
23.2 Outline the timing of the stages of the technology of tool development.
23.3 Describe the stone artefacts characteristic of Oldowan technology and use evidence from Nicholas Toth's experimental studies to suggest how they were made and used.
23.4 Explain evidence from study of living apes e.g.Kanzi the bonobo, that supports the view that the Oldowan tool makers were not apes.
23.5 Discuss and assess the evidence relating to the identity of the Oldowan tool makers.
23.6 Identify and explain evidence derived from recent finds that supports the use of tools by australopithecines.

SAQ 23.1 (Objective 23.6)
Look in "News online" in the S292 web site for the item "Ape man ate termites", which reports new research on Australopithecus robustus. How did researchers prove that the tools found in association with the fossil remains of Australopithecus robustus were being used to fish for termites? Write no more than 100 words.
SAQ 23.2 (Objective 23.4)
Click on the Bossou chimpanzees web site, available on the S292 web site. Write no more than 100 words.
http://www.pri.kyoto-u.ac.jp/chimp/Bossou/Bossou.html

How would you distinguish the making and use of tools by the Bossou chimpanzees from the making and use of Oldowan tools?

Part Six: Out of Africa

Unit 24 The changing position of Homo erectus
New fossil finds and re-interpretation of known fossils have changed views of the evolutionary sequence between early Homo and Homo sapiens. Fossil finds of Homo erectus in Africa, include KNM-ER 3733, from Koobi Fora, dated at 1.8 million years, and Ternifine, Algeria, dated between 600 000 and 700 000 years. Asian finds include a cranium from Java dated at 1.6 million years, which complicated earlier views that H. erectus originated in Africa and spread into Asia after a delay of 1 million years.

The older African specimens have been assigned to Homo ergaster which may have originated in Africa 2 million years ago, then expanded its range into Asia* where it evolved into Homo erectus. The later appearance of Homo erectus in Africa could derive from either Asia-Africa migration or Homo ergaster could have given rise to Homo erectus in Africa.

Study of the Turkana boy skeleton, dated at 1.6 million years old, provided insights into the anatomy and behaviour of Homo ergaster, in particular evidence for prolonged childhood. Other clues derive from the accumulations of bones and stones found associated with the H. ergaster/erectus fossils.

*Look at the Homo erectus specimens in the filing cabinet of the Virtual Office.
See description of Homo ergaster fossils found in Dmanisi, Georgia, dated at 1.8.mya.

Objectives
24.1 Summarize current views on the evolution of Homo sapiens from early Homo.
24.2 Interpret an annotated map e.g. p. 139, identifying where fossils of Homo erectus were found and link the locations of the finds to the migration and evolution of Homo erectus.
24.3 Explain the problems of using fossil evidence to suggest the pattern of evolution and migration of Homo erectus.
24.4 Appreciate the rationale for splitting Homo erectus into two species, Homo erectus and Homo ergaster.
24.5 Explain the reasoning that supports (a) the presence of infant helplessness and prolonged childhood in Homo ergaster, (b) the evolution of Homo ergaster/erectus signals the appearance of a new grade of hominine evolution.
24.6 Explain how the dating of recent finds of two Homo ergaster skulls at Dmanisi provides clear evidence of the migratory behaviour of Homo ergaster.

SAQ 24.1 (Objectives 24.2, 24.3, 24.6)
Search the S292 web site for news about the finds at Dmanisi, of two Homo ergaster skulls associated with stone tools; skulls and tools were dated at 1.75 mya Describe the finds and explain their implications, with regard to expansion of Homo out of Africa into Asia and Europe. Write up to 150 words.

Unit 25 New technologies
Fossil and archaeological evidence for subsistence patterns and social structure of H. ergaster and H. erectus suggest similarities to human behaviour. The Acheulean stone tool assemblage is characterised by the teardrop-shaped handaxe and is associated with meat-eating in populations of H. ergaster/erectus. Suggested uses for the handaxes include slicing through tough hides, chopping bones and wood. Locations and ages of Acheulean assemblages include Konso-Gardula, Ethiopia, dated at 1.4 million years, Olorgesailie, Kenya, dated at 700 000 years, to Arago, France, dated 300 000 years.

There are many other sites in western Asia and Europe where Acheulean assemblages have been found. The lack of handaxes in assemblages in Eastern Asia, east of the "Movius line" may relate to the use of bamboo for knife making by Homo living there, or cultural or historical reasons.

Acheulean technology ended 200-300 000 years ago in the Old World, having lasted at least 1 million years. The end of Acheulean technology marked the end of the Lower Paleolithic (Early Stone Age) and the beginning of the Middle Paleolithic (Middle Stone Age).

Objectives
25.1 Describe the salient features of the tools that define the Acheulean assemblage and distinguish it from the Oldowan assemblage.
25.2 Outline the geographical distribution of the Acheulean assemblage and suggest interpretation of the Movius line.
25.3 Explain how Acheulean assemblages show some overlap with Oldowan assemblages and that there is geographical variation in the form of individual tools within the Acheulean.
25.4 Suggest functions for Acheulean tools from illustrations such as those on p. 146.

SAQ 25.1 (Objectives 25.1, 25.2)
Compare and contrast the techniques used to make Oldowan and Acheulean stone tools. Information is available on the S292 website as well as in Lewin. Write up to 150 words.

Unit 26 Hunter or scavenger?
Interpretations of stone tool and animal bone assemblages are controversial and have led to at least four hypotheses about early hominine subsistence. In the 1960's and early 70's, co-operative hunting was regarded as primary hominine behaviour. Glynn Isaac's 'food sharing' hypothesis proposed that meat and plant material were brought back to a home base for sharing out amongst the group. Lewis Binford's analysis of published material on Bed 1 at Olduvai concluded that the huge accumulation of bones there derived from carnivore activity, with some scavenging of bones by hominids. Isaac's co-workers, Potts, Shipman (Pennsylvania State University) and Bunn, (University of Wisconsin) argued that the bone collections derive from hominine activity with some input by carnivores. Potts concluded the accumulations of bones resulted from a mixture of scavenging and hunting. Cut marks discovered on the bones were interpreted as evidence that hominines were using the bones for food, but it is not possible to distinguish scavenging from hunting.

Isaac suggested the 'central place foraging' hypothesis in response to findings that suggest the concentrations of bones and stones were meat processing sites, not home bases. Accumulations of stones and bones at site 50, Koobi Fora dating around 1.5 mya, suggest this was more like a camp site.

Objectives
26.1 Explain the following: hunting hypothesis; the home-base food-sharing hypothesis; the central-place foraging hypothesis
26.2 Assess evidence from cutmarks and toothmarks on fossil animal bones.
26.3 Suggest hypotheses to explain the accumulation of stone artefacts and broken animal bones in the same location.
26.4 Discuss the significance of the evidence for hunting versus scavenging at the Olduvai site.
26.5 Explain why Glynn Isaac suggested replacing his home-base food-sharing hypothesis by the central-place foraging hypothesis.

SAQ 26.1 (Objectives 26.2, 26.3 )
View "News online" and find the item "Friendly fire". The article describes research at the Koobi Fora site. Summarise the evidence that suggests humanlike subsistence behaviour at Koobi Fora. Write up to 150 words.

Part Seven: The origin of modern humans
Before reading Part 7 examine the specimen skulls of Homo heidelbergensis, Homo neanderthalensis and Homo sapiens in the filing cabinet of the Virtual Office.

Unit 27 The Neanderthal enigma
Neanderthals lived in Europe, Asia and the Middle East from 150-30 000 years ago and were the first fossil humans to be discovered. Neanderthal anatomy is a mix of primitive and derived characters, with body shape indicating adaptation for life in a cold climate and possession of great muscular strength.

Available evidence indicates that Neanderthals lived in small nomadic groups, subsisting by hunting and gathering, using caves as temporary bases*. Two types of Middle Paleolithic tool assemblage are associated with Neanderthals, Mousterian and Chatelperronian. There are a number of views on the relationship between Neanderthals and modern humans. Loring Brace's (University of Michigan) version of the unilinear hypothesis suggested 4 stages:

australopithecines > pithecanthropines > Neanderthals > modern humans.

Fossil finds show that at least 2 million years ago, Australopithecus boisei was coexisting with Homo ergaster, thereby disproving the unilinear hypothesis. Wolpoff, (University of Michigan), still supports a unilinear hypothesis for an evolutionary pathway direct from Neanderthals to Homo sapiens. Limited evidence from studies on Neanderthal mtDNA indicate that it is so different from modern human mtDNA that Neanderthals could not have been the direct ancestors of modern humans.

*Visit the Gibraltar museum site. This includes description of finds in Vanguard and Gorham's caves in Gibraltar, which provide insight into Neanderthals' way of life.

Objectives
27.1 Outline archaeological evidence for the view that Neanderthals lived in small groups, subsisting by hunting and gathering; evidence for culture derives from stone tools and deliberate burials of their dead..
27.2 Explain how Neanderthal anatomy indicates robust build and adaptations for living in a cold climate.
27.3 Outline the features of Neanderthal stone tool technology and distinguish between Mousterian and Chatelperronian technology.
27.4 Summarize the evidence that about 40 000 years ago, modern humans appear to have co-existed with Neanderthals.
27.5 Outline the following late 19th century and early 20th century views of the place of Neanderthals in human evolution: a stage in unilinear evolution of H. sapiens; an evolutionary dead end; the pre-sapiens theory.
27.6 Outline the results of studies on mtDNA in Neanderthal fossil material and discuss their significance.

SAQ 27.1 (Objectives 27.1, 27.3)
Access the Gibraltar Museum Site, and find information about the finds in Vanguard and Gorham's caves. Outline the insights into the Neanderthal way of life provided by the fossil and archaeological finds in the caves. Write no more than 150 words.

Unit 28 The origin of modern humans: anatomical evidence
Two opposing hypotheses explain the origin of anatomically modern humans. The multiregional hypothesis proposes that Homo sapiens evolved by gradual change in all populations of Homo erectus leading to near simultaneous appearance of modern humans in Africa and Eurasia. The out of Africa hypothesis proposes that modern humans evolved once in Africa and expanded into the Old World replacing non-modern populations.

The hypotheses can be tested by assessing how accurately their predictions are proved in the fossil record. The earliest anatomically modern human fossils are found in Africa and the Middle East and the pattern of their appearance supports the predictions of the single origin hypothesis more strongly than those of the multiregional hypothesis. Regional continuity of anatomical features from ancient to modern populations would support the multiregional hypothesis.

Unit 28 looks at the evidence for regional continuity in fossils from Australasia, East Asia, the Middle East, Europe and Africa, but there is little, if any. Overall there is more evidence that supports the single origin hypothesis, in particular from the Middle East.

Objectives
28.1 Outline the two extreme hypotheses for the origin of modern humans: the multiregional evolution hypothesis and the single origin hypothesis.
28.2 List the predictions relating to the two extreme hypotheses.
28.3 Interpret maps showing migratory routes of Homo erectus and modern humans and relate them to maps indicating locations of important fossil finds.
28.4 Interpret drawings of fossil crania and where possible deduce relationships between them based on similarities and differences
28.5 Summarize the findings of the fossils of anatomically modern humans and explain how they support or refute (a) the multiregional evolution hypothesis and (b) the single African origin hypothesis.

SAQ 28. 1 (Objectives 28.1, 28.2, 28.5)
View the "Neanderthals and modern humans" website. Search for information about the re-dating of the Neanderthal and modern human fossils found on Mount Carmel, Israel. What dating techniques established the correct ages of the fossils? How does the re-dating of the fossils change the view about the evolutionary relationship between Neanderthals and modern humans? Unit 28 also has relevant information. Write up to 200 words.

Unit 29 The origin of modern humans: genetic evidence
The mitochondrial Eve hypothesis claims that mtDNA in all living people can be traced back to one female living in a population of about 10 000 people in Africa about 200 000 years ago. This is consistent with the recent single African origin model and gives no support to the multiregional evolution model. mtDNA is useful for tracking evolutionary events because of its relatively high rate of mutation providing a molecular clock, and its maternal origin. Africans show the greatest variation in mtDNA, taken to indicate the African population as being the oldest.

Maryellen Ruvolo's (Harvard University) study of the clustering of coalescence times for various genetic loci favours the recent single origin model. Study of coalescence times for microsatellite DNA and Alu elements adds further support for recent single origin. The technique of mismatch distribution indicates that the low level of diversity in mtDNA relates to a severe bottleneck in the early human population, followed by a population explosion.

Harpending and Roger's (University of Utah) work used the technique of mismatch distribution to work out past population events. They concluded that the human population underwent a rapid expansion about 60 000 years ago, but at different precise times for particular geographical populations. The technique of intermatch distributions indicates the African population exploded first followed by the European and Asian populations. Therefore the Garden of Eden hypothesis, which suggests that modern humans originated as a small population whose descendants spread throughout the Old World is not quite appropriate. The weak Garden of Eden hypothesis provides a more realistic explanation whereby the founding population of humans spread out over the Old World, but the separate expansions took place at different times, (see chart on p 181).

Objectives
29. 1 Outline the mitochondrial Eve hypothesis.
29.3 Explain how findings from study of variation in mitochondrial DNA support an African origin for modern humans rather than the multiregional evolution hypothesis.
29.4 Outline how the results of calculations of coalescence times for genetic loci, including nuclear and mtDNA support the recent origin model for Homo sapiens.
29.5 Explain how studies of mutations in Alu DNA elements and microsatellite DNA favour the recent single origin model for Homo sapiens.
29.6 Show how the technique of mismatch distribution indicates that the modern human population suffered a severe bottleneck early in their history that explains the low genetic diversity of mtDNA in modern populations.
29.7 Explain how the evidence from intermatch distribution analysis of mtDNA data indicates different timings for the population expansion of different human populations around 60 000 years ago and how this fits in with the recent single origin model.
29.83Define the weak Garden of Eden hypothesis, highlighting differences from the Garden of Eden hypothesis.

SAQ 29.1 (Objectives 29.1, 29.2, 29.3, 29.7, 29.8)
Classify the following statements as true or false giving brief explanations as appropriate:
(a) The mitochondrial Eve hypothesis states that all mitochondrial DNA types found in humans living today derive from one woman, the first and only female Homo sapiens living at the time.
(b) African people show the greatest variation in their mtDNA which is consistent with the view that the African population of modern humans is the oldest and that modern humans originated in Africa.
(c) The Garden of Eden hypothesis is essentially the same as the recent-single origin hypothesis for modern humans.
(d) The weak Garden of Eden hypothesis states that separate populations of archaic Homo sapiens in Africa, Asia and Europe evolved into populations of anatomically modern humans.
(e) Mismatch and intermatch distribution data indicate that the founding population of modern humans split into separate populations, which later spread out in Africa and thence to Europe and Asia

Unit 30 The origin of modern humans: archaeological evidence
Archaeological evidence relating to the origin of modern humans is good in Europe and W Asia, but relatively poor in Africa. New finds in Africa are initiating a fresh look at the behavioural evolution of H. sapiens during the Middle and Upper Paleolithic. Many industries in the European Upper Paleolithic are defined by blades, flakes with length at least double their width, made from prepared cores. The appearance of blades in Europe 40 000 years ago is regarded as a revolutionary change coinciding with the appearance of modern humans in Europe and also use of bone, ivory and antler for points and decorative beads. Asian evidence is equivocal and paradoxical. African evidence of blade production in central Kenya, dates back 240 000 years (Brooks, George Washington University, and McBrearty, University of Connecticut).

In Africa, pigments and stones for processing pigments date back 80 000 years, and beads 60 000 years. The later appearance of modern cultural activities in Europe co-incides with the first appearance of anatomically modern humans, migrants, originating from Africa.

*View Web Links and find the Blombos cave sites. Revisit the Gibraltar museum site, to compare Neanderthal artefacts found in Gorham's and Vanguard caves, with artefacts found at Blombos cave.

Objectives
30.1 Appreciate the archeological background that gives evidence for early modern human behaviour.
30.2 Explain the technological advances from Middle to Upper Paleolithic in Europe: blade production from prepared cores and use of bone antler and ivory, giving approximate dates.
30.3 Suggest a possible explanation for the finding of a Neanderthal skeleton, dated at 36 000 years, associated with Chatelperronian technology at Saint-Césaire.
30.4 Demonstrate that Asian evidence is equivocal, giving examples.
30.5 Summarize the African archeological evidence for emergence of modern human behaviour earlier than in Europe.

SAQ 30.1 (Objectives 30.1, 30.5)
Outline two lines of evidence that support the view that modern human behaviour began earlier in Africa than in Europe. One line of evidence, Professor Henshilwood's study of the artefacts and fossils in Blombos cave South Africa, is available on the S292 web site. Select one other line of evidence from Unit 30. Which of the models for the origin of modern humans is supported by the two lines of evidence, the "out of Africa model" or the multiregional hypothesis? Write up to 150 words.

Part Eight: The human milieu

Unit 31 Evolution of the brain, intelligence and consciousness
Certain factors enable development of a large brain in humans: high maternal metabolic rate, long gestation, litter size of one, stable high energy food supply and minimum predation pressure. Secondary altricialty in humans prolongs brain development but has social implications as human infants need a prolonged period of care.

Encephalisation quotient, EQ, a measure of brain size related to body size, increases steadily from australopithecine species, through early Homo, Homo ergaster/erectus to modern humans. There are clear differences between apelike and humanlike brain organisation, (see diagram on p190), but there is controversy about when humanlike brain organisation evolved in hominine history, e.g between Dean Falk and Ralph Holloway.

There are no direct indications of intelligence in the fossil record, but stone tools offer some clues. Selective pressures favouring hominine brain expansion have been related to tool-making skills, hunting skills and most recently to social skills within a group setting.

Objectives
31.1 Discuss factors that enable development of a large brain that in humans consumes about 18% of the total energy budget.
31.2 Compare the typical brain pattern and organization in ape and human.
31.3 Summarize hypotheses relating to timing of appearance of human brain organization in prehistory using evidence from brain endocasts and values for encephalization quotients in fossil hominids and hominines and modern humans.
31.4 Describe how the relationship between patterns of growth in precocial and secondarily altricial young affects growth and development of the brain and also the social life of hominines.
31.5 Appreciate the selective pressures that may have resulted in brain expansion: advantages related to tool-making, hunting and social interactions.
31.6 Link brain expansion in Homo to advances in stone tool technology.

SAQ 31.1 (Objectives 31.1, 31.2, 31.3)
Summarize information on brain size, pattern and organization in ape, Australopithecus, early Homo, Homo ergaster/erectus and modern humans in a chart of your own design.
What can you conclude from your table about the timing of the appearance of human-like brain organisation in prehistory?

Unit 32 The evolution of language
As language is invisible in the archeological record, clues are gleaned from indirect sources, e.g. stone tools, paintings, fossils. A central question is whether language emerged slowly, beginning early in hominine history, or developed rapidly.

Fossil evidence derives from brain endocasts and the anatomy of voice-producing structures in the neck, the larynx and pharynx. However language capability cannot be located precisely to a particular part of the brain. Broca's area is associated with production of sound and there is evidence for its presence in brain endocasts of H. rudolfensis, but not in australopithecines.

There is argument about when language capacity was developed in the Homo lineage and whether australopithecines developed language capacity. Evidence from prehistoric tool-making and art indicates that language evolved rapidly and recently. The selective pressures for evolution of language and intelligence relate to communication, particularly in a social group setting. Clearly different lines of evidence lead to different conclusions about the dynamics of evolution of language.

Objectives
32.1 Describe how evidence relating to the evolution of language is derived from indirect sources, e.g. fossil skulls, stone tools, cave paintings.
32.2 Explain how the position of the larynx and the shape of the basicranium in fossil skulls offer clues about the verbal skills of extinct hominine species.
32.3 Evaluate the evidence that indicates gradual evolution of language capabilities, in particular, location of larynx in neck, brain endocasts.
32.4 Describe the evidence for the rapid and recent evolution of language, including the relatively recent (~32 000 years ago) and sudden appearance of cave paintings, and the sudden improvement in stone tools, around 40 000 years ago (in Europe at least, probably earlier in Africa).
32.5 Explain hypotheses for the selective advantage of language skills for social hominines living in groups.

SAQ 32.1
Outline the selective advantages that may have promoted the development and refinement of language in Homo. Write up to 100 words.

Unit 33 Art in prehistory
The rich prehistoric art in Europe offers useful hints about how early humans perceived their world. During the first half of the 20th century, Abbe Henri Breuil made a systematic study of prehistoric cave art in France and prepared a chronology based on artistic style. His chronology was upset by the discovery of the cave paintings at Chauvet*, dated at 32 410 years, which are equal in quality to those at Lascaux, dated much earlier at 15 000 years. Generally painted images comprise animals such as deer, horses and bison and rare paintings of carnivores, but at Chauvet, paintings of carnivores are common, e.g. hyena, leopard. Breuil suggested the 'hunting magic' hypothesis explaining the paintings as a means of ensuring good hunts and propitiating the victims. Leroi-Gourhan and Laming-Emperaire suggested cave art represents duality of maleness and femaleness in society.

However it is agreed now that monolithic explanations of the meaning of cave art are inappropriate. Cave paintings are diverse and vary with time, geography and also possibly different shamanistic rituals. There is little evidence of art prior to the Upper Paleolithic, but Phillip Chase and John Lindly see the Middle to Upper Paleolithic transition as gradual, not punctuational.
Visit the Chauvet and Lascaux caves and view the paintings.

Objectives
33.1 Describe how the discovery of Chauvet cave upset previously made generalizations that, (i) carved and engraved images preceded painted images by at least 10 000 years, (ii) carnivores were rare in cave paintings because of the fear and respect of prehistoric peoples for fellow predators.
33.2 Describe examples of cave paintings, including animals, geometric figures and hand stencils (e.g. from photograph in Lewin, p.202; from images on the web)
33.3 Describe examples of engraved or carved images (e.g. from photographs on p. 202).
33.4 Summarize Abbé Henri Breuil's views on the chronology and purpose of cave paintings, and explain his hunting magic hypothesis.
33.5 Explain why there cannot be a monolithic explanation of the meaning of Upper Paleolithic art, and outline the evidence for diversity of meaning.
33.6 Evaluate evidence for the existence of image making earlier than the Upper Paleolithic.

SAQ 33.1 (Objectives 31.1, 31.2, 31.3)
Visit the website about the Chauvet cave. You will need to spend some time exploring the cave. Which animals are depicted in the Chauvet cave? What is unusual about the animals depicted? Describe finds other than art in the cave.

SAQ 33.2 (Objectives 33.3, 33.6)
Visit "News Online" and find "Oldest prehistoric art unearthed". The news item describes an engraved piece of ochre found at Blombos cave, South Africa. Describe the find and explain its significance.

Part Nine: New worlds

Unit 34 New worlds
Major dispersals of populations of modern humans in prehistoric times have fascinated paleoanthropologists. It is generally agreed that the Americas were colonised by migrants, the Clovis people, from Asia about 12 000 years ago, during the Pleistocene Ice Age. Their migration route may have been an ice-free corridor linking Siberia and North America (see map on p208). Most evidence of populations preceding the Clovis people derives from finds in South America e.g. the Monte Verde site in Chile, dated at 12 500 years. Other evidence derives from Joseph Greenberg's study of 600 Indian languages, which he classified into 3 source groups, Amerind, Aleut-Eskimo and Na-Dene, and suggested the 3 linguistic groups relate to 3 separate migrations.

The rapid extinction of large mammalian species such as mammoth, mastodon, following the arrival of the Clovis people has been attributed to hunting (see diagram on p212). Ernest Lundelius (University of Texas) argues that climate change at the end of the Ice Age caused the extinctions. The Clovis people were replaced by the Folsom people)-most large mammalian species were extinct by the time the Folsom people arrived.

Migrations to Australia had to be by means of sea voyages but no archeological evidence of sea-going vessels has been found. The oldest human fossils found in Australia were at Lake Mungo and dated at *25 000 years - these fossils are gracile. More robust fossils were found at Kow swamp in S.Australia, dated at 12 000years old. Evidence from mtDNA suggests that Australia was colonised at least 15 times!

*See S292 website for important information on re-dating of the Lake Mungo fossils and an explanation of Alan Thorne's study of mtDNA extracted from the fossil bones of Mungo man.

Objectives
34.1 Describe the two major dispersals of modern human populations in prehistoric times, one into the Americas and one into Australia.
34.2 Explain the migration of the Clovis people from Asia to the Americas in the context of the time it took place, the Ice Age, and the likely route followed by the populations.
34.3 Give a brief account of the possible effect of the Clovis people on the animal populations.
34.4 Describe evidence for population migrations to the Americas that may have preceded the Clovis people.
34.5 Explain how the finding of both gracile (dated at 60 000 years) and robust (dated at 12 000 years) human fossils in Australia may or may not indicate that the earliest colonists were anatomically variable.

SAQ 34.1 (Objective 34.1)
Access the S292 web site and click on "Site reviews" and then on "Mungo man", which explains how the Mungo man fossils were originally dated at around 25 000 years by radiocarbon dating. Re-dating of the fossils has established that Mungo man is considerably older than was first thought, about 60 000 years old. Explain the significance of the re-dating with regard to the ability of the first Australians to undertake migration to Australia from SE Asia. Write up to 100 words.

Unit 35 The first villagers
Development of agriculture began about 12 000 years ago, beginning in the Fertile Crescent of the Near East, followed by MesoAmerica and SE Asia. Archeological and ethnographic evidence suggests that late Pleistocene hunter-gatherers were living in small sedentary communities before agricultural development began.

The example of Abu Hureyra indicates a gradual transition from a hunter-gatherer lifestyle to agriculture. The finding of a settlement of 5 large dwellings made of mammoth bones on the Central Russian Plain, dated at 15 000 years, offers more evidence of the complexity of the late Pleistocene. Such discoveries exposed the shortcomings of the views on the simple hunter-gatherer lifestyle that had been based on the life of the !Kung bushmen of the Kalahari.

The question of how agriculture spread is a difficult one, and the answers proposed include population migration and the spread of the idea. Two causes of the switch to agriculture have been suggested, population pressure and climate change. A key question is why it took about 90 000 years after the emergence of modern humans for agriculture to develop. Overall it is clear that no single factor explains the switch to agriculture, or its spread.

Objectives
35.1 Summarize the evidence that indicates that the Neolithic revolution was a stepwise process rather than an explosive change.
35.2 Quote archeological evidence for social and economic complexity during the late Pleistocene, including that from the site of Abu Hureyra, Upper Paleolithic cave art in Europe and the mammoth bone village, near Mezhirich, Central Russia, dated at 15 000 years.
35.3 Describe how the findings of the !Kung project were used as a model for the hunting and gathering lifestyle in prehistory and explain why this is now considered to be inappropriate.
35.4 Explain the two views relating to the spread of agriculture: by population migration; by the spread of the 'idea'.
35.5 Discuss the possible causes of the transition to food production: a rise in population numbers; climatic change; increasing social complexity.

SAQ 35.1 (Objectives 35.1, 35.2)
View Web Links and find the Kostenki websites. Describe the evidence at Kostenki that supports the view that hunter-gatherers were living in a semi-permanent or permanent settled village, around 24 000 years ago. Do the findings of the!Kung project provide an appropriate model for the lifestyle of the Kostenki hunter gatherers? Write up to 100 words.

ANSWERS TO SAQs
SAQ 1.1
Before 1859, the superiority of humans to other living organisms was explained as the product of God's creation. Following publication of the Origin of Species, naturalistic explanations were used to account for humans' exceptional intellectual and spiritual and moral qualities. The 'Chain of Being' comprised a set of creatures placed by God in fixed positions of ascending hierarchy, from the lowest organisms to the highest, with humans at the top just below the angels. After 1859, the 'Chain of Being' was explained by the progress of evolution with gradation from the lowest organisms up to 'lower' and 'higher' races of humans.

SAQ 2.1
A sample answer!
Our ancestors, intelligent apes, descended from trees to stand tall on two legs and run free on the African savannah. They used their sharp intellect to find food and to overcome attacks by wild animals. As the apes became more human-like , they shaped stones into spearheads, knives and axes for hunting and cutting up meat. Linked to his family group by bonds of loyalty and affection, early Man provided his women and children with food, learning to live in communities and to work co-operatively with others. Early Man noticed the beauty of the world and painted colourful pictures in underground caves. Ever curious, early Man's explorations led to migrations over land and sea until virtually all land on our planet had been conquered. Technology advanced from stone tools through use of bone, then metals, to computer and rocket science.

SAQ 5.1
Twenty million years ago during the Miocene, Mightopithecus lived in the vast tropical forest covering Africa. Fossils indicate a number of ape-like characterisitics for Mightopithecus. Uplift caused by tectonic activity created physical barriers to population movement. In the eastern part of the continent, the rain shadow created a drier climate where forest was fragmented and largely replaced by open savannah. Populations of Mightopithecus were thereby isolated by both physical barriers and habitat fragmentation. Natural selection acting on variants in. isolated populations resulted in their divergence and eventually eventually allopatric speciation. A number of diverse species of hominoid evolved from the ape-like ancestral species, Mightopithecus, each adapted for life in a particular habitat (or niche).

SAQ 6.1
(a) False. Evolution does not occur with a specific purpose or direction. Evolution proceeds by means of natural selection.
(b) False. There is evidence that the end-Cretaceous extinction was the result of Earth's collision with an asteroid. However well adapted an animal may be to its environment, there is no adaptation that could could protect an animal from an unforeseen massive disaster.
(c) True. This was one of the findings made by David Jablonski (see p. 29, Lewin).
(d) True: Mass extinctions open up opportunities for adaptive radiation of survivors.

SAQ 7.1
Rocks contain a small amount of radiopotassium, K-40, which decays into its daughter, the gas argon-40, Ar-40. The time taken for half of a given amount of K-40 to decay is known and is called the half-life. Melting of rocks during a volcanic eruption drives out gases from the rock, including Ar-40. This resets the radiometric clock to zero. Ar-40 accumulates again as K-40 decays. Since the half-life of K-40 is known, the proportion of Ar-40 relative to K-40 in a rock enables the age of the rock to be calculated.
Sedimentary rocks are formed by accumulation of pre-existing mineral grains, e.g. sand. Therefore the radiometric age determined from a sedimentary rock would be that of the rock from which the sand grain was originally derived, e.g. granite. The age of the granite could be thousands of millions of years older than that of the sedimentary rock.

SAQ 8.1
Phenetics is the school of classification closest to the Linnaean system because only anatomical features are taken into account, albeit in the context of adaptation.

SAQ 8.2
There are many examples of analogy. The wings of insects and birds are analogous characters. Insects are not related closely to birds. Insects have a completely different body plan to birds. The fins of fish and squid are analogous characters as are the eyes of squid and vertebrates.
Homoplasies, i.e. analogous characters, cannot be used to reconstruct phylogenies because by definition they occur in groups that are not related closely. Natural selection acting on characters in widely divergent organisms living in the same habitats and feeding on similar foods tends to result in similar adaptations. The adaptations do not relate only to the animal groups; they relate to the way of life of the animals. For example, swimming animals tend to have streamlined torpedo-shaped bodies, e.g. squid, fish, penguin, whale, but each of these animals is a member of a different group.

SAQ 9.1
(a) False. With no fossils of early Homo found in association with stones and bones it is not possible to establish any relationship between Homo and the stones and bones.
(b) Uncertain. Taphonomists disagree on whether cut marks found on fossil animal bones were madeed by stone tools. Marks on bones trampled by hoofed animals can resemble stone-tool cut marks. Sandra Olsen and Pat Shipman claim their experiments have shown that cut marks can be distinguished from effects of trampling.
(c) True. The finding of assemblages of stone tools, animal bones and fossils of early Homo at Olduvai Gorge indicate an association between early Homo and use of stone tools.
(d) False. Cuts and abrasions on bones can also be caused by trampling and gnawing by carnivores
(e) False. Bones and stones at Olduvai appear to have accumulated over periods of 5-10 years, far too long when compared to home bases of modern hunter-gatherer peoples.

SAQ 9.2
The bone is a smashed antelope thigh bone. The marks on the bone were interpreted as indicating that the bone was broken open by means of stone tools. You can also see what look like cut marks possibly made during de-fleshing of the bone with a stone tool. The researchers concluded that A.garhi was eating bone marrow, a fatty nutritious food and possibly meat too.
As pointed out by Behrensmeyer and colleagues, (Lewin, p 48) such marks could also be interpreted as abrasions caused by trampling. Damage from a strike by a hoof probably resembles damage from a strike by a sharp stone.

SAQ 10.1
(summary of points on p 51, Lewin)
-A primate is an arboreal animal living in tropical and sub-tropical forest; this does not apply to humans who live in a huge range of habitats.
-Primates have grasping hands and feet with opposable thumbs and great toes. Hands and feet have ridged finger and toe pads; hands are touch sensitive. These features apply to humans. However, human feet are adapted for upright walking and have lost the grasping function.
-Locomotion in primates is hind-limb dominated; this applies to bipedal humans!
-Vision is highly developed with eyes at the front of the head producing stereoscopic vision. Olfactory sense is reduced. This applies to humans.
-The snout is shortened; there is reduction of the number of incisors and front teeth. This applies to humans.
-Large brains reflect increased intelligence in primates, including humans. Reproductive output is low with greater longevity. This applies to humans.
-Gestation period is long with small litters, often just one. This applies to humans.
-Age at first reproduction is late; certainly true for humans.

SAQ 10.2
Elliot Smith and Wood Jones' arboreal hypothesis suggests that primate features derive from adaptations for life in trees. Grasping hands and feet enable effective locomotion through branches and vision is more important than olfaction for animals living amongst leaves and branches. Cartmill's visual predation hypothesis suggests that primate adaptations link to the ability of a small arboreal animal to stalk insect prey caught with the hands. Cartmill's arguments against the arboreal hypothesis include the point that most arboreal mammals lack one or more of the primate adaptations. Squirrels have divergent eyes; opossums lack the short face, reduced olfaction and large brains of tree-dwelling primates but both are just as effective as primates at living in trees. If primates have the most effective adaptations for arboreal life, they would be expected to be the most skilful arboreal animals but they are not. Cartmill's visual predation hypothesis is accepted as the most reasonable view (see Lewin, p 53).

SAQ 11.1
Bergmann's rule predicts that people living in warm parts of the world will be smaller bodied than those in cold areas. Homo ergaster living in a warm open environment, were very tall e.g. Turkana boy. Males were up to 1.8m tall and weighed about 63 kg; females were about 1.55m tall and weighed about 52 kg. Neanderthals lived during the Ice Age in Europe and endured an extremely cold climate. Males were about 1.6 m tall and weighed about 84 kg; females were about 1.5 m tall weighing about 80 kg. Overall Neanderthals were considerably larger and their body width was greater than Homo ergaster, both trends consistent with Bergmann's rule. According to Allen's rule, populations living in warm regions will have longer extremities than those living in cold regions. The anatomy of Homo ergaster, with long thin limbs which maximize heat loss, fits in with Allen's rule. The short stout limbs of Neanderthals would help to reduce heat loss from the extremities as predicted by Allen's rule.

SAQ 12.1
The mouse lemur offers an appropriate model for life history strategies in Eosimias. Body size is a useful predictor; tiny body size indicates r-selection. Animals as small as the mouse lemur, and by extrapolation, Eosimias, live short "fast" lives, mature early, produce large litters after a short gestation period and wean early. It is likely that Eosimias had a high reproductive output with high juvenile mortality.

http://news.bbc.co.uk/hi/english/sci/tech/newsid_678000/678458.stm

http://abcnews.go.com/sections/science/DailyNews/fossil000315.html

SAQ 13.1
Wrangham's model explains that if food resources are in patches that can only support one female and her young, females forage alone with their offspring. This is the case for the orangutan, which feed on tree fruits. Each female has her own territory. A single male defends a 'community' of lone females, unimale polygyny. The male defends the females from other males and is twice the size of the female.
The gorilla feeds on low quality vegetation found in abundant patches. A single male, the silverback, controls a group of 2-20 females and their young. This is also unimale polgyny, but different from that in the orangutan. As food is abundant, one male can assemble females in a group. The male gorilla is larger than the female.

SAQ 14.1
(a) Untrue. A gorilla-like social structure for ancestral hominines would not imply that the animals looked like gorillas although it would be reasonable to expect a degree of body size dimorphism comparable with that in gorillas.
(b) Untrue. Lions do hunt co-operatively, but this behaviour is analogous to cooperative behaviour in hominines, not homologous.
(c) True. Evidence that sexual dimorphism in body size in Australopithecus afarensis relates to extreme competition between males for females, derives from observations on orangutans.
(d) False. There is evidence that Homo ergaster/erectus were meat-eaters. Meat is a resource distributed patchily over a wide area which would require alliance of males in a group setting, not defence by individuals (p 76, Lewin)

SAQ 14.2
No: comparison of sexual dimorphism in body size in gorilla with that in Homo ergaster, does not suggest a similar social structure in the two species. Gorillas live in dense forest and feed on low quality herbage. Male silverbacks weigh up twice as much as females, and have enlarged canine teeth, features linked to a social structure with extreme competition between males for access to females. There is evidence that Homo ergaster in Africa lived in tropical savannah. Average height for male Homo ergaster was about 1.8 m and weight about 63 kg; for females average height was about 1.55.m and weight around 52 kg. Male Homo ergaster were about 20% heavier than females. Homo ergaster ate meat; species that eat meat, a high quality but patchily distributed resource, need to defend sufficient territory. For a social animal this requires co-operation and therefore alliances of males, probably related males, as in the chimpanzee. Canine teeth of Homo ergaster were small. Brain size in Homo ergaster was about 650 -800cm3 (see skull index card). It takes a long time and much energy to rear large-brained offspring so females would have relied on support from males and the group to provide for their offspring.

SAQ 15.1

Summary of comparisons between skulls of chimpanzee and Homo sapiens.

Chimpanzee	Human
Face shows marked prognathism	Face flat
Long mandible	Mandible reduced in length
No forehead	Large smooth forehead
Large eyebrow ridges	No eyebrow ridges
Cranium slightly domed	Large bulbous cranium
Enlarged projecting canine teeth with sharp points	Canine teeth small, blunt and flat
There is a diastema in both upper and lower jaws.	No diastema is present
Incisors project forwards	Incisors flat do not project
Large orbits	Large orbits
Eyes face forwards	Eyes face forwards
Dental formula: 2I 1C 2P 3 M	Dental formula: 2I 1C 2P 3 M

*apelike features of Proconsul skull

SAQ 15.2
Goodman's scheme reflects the close evolutionary relationship between chimpanzees and humans. Gaylord Simpson argues that an ape grade exists that is distinct from the human grade. Goodman's scheme discards that distinction (but note that the distinction between ape and human grade is valid with regard to brain development, see Units 23 and 31).

SAQ 16.1

Chimpanzee	Human	Proconsul
Face shows marked prognathism	Face flat	Face shows marked prognathism*
Long mandible	Mandible reduced in length
No forehead	Large smooth forehead	No forehead
Large eyebrow ridges	No eyebrow ridges	Slight eyebrow ridges
Cranium slightly domed	Large bulbous cranium	Cranium looks slightly domed
Enlarged projecting canine teeth with sharp points	Canine teeth small, blunt and flat	Huge projecting sharply pointed canines*
There is a diastema in both upper and lower jaws.	No diastema is present	There is a diastama in both upper and lower jaws*
Incisors project forwards	Incisors flat do not project	Incisors project forwards*
Large orbits	Large orbits	Large orbits
Eyes face forwards	Eyes face forwards	Eyes face forwards
Dental formula: 2I 1C 2P 3 M	Dental formula: 2I 1C 2P 3 M

*apelike features of Proconsul skull

SAQ 17.1
The chimpanzee in the video clip stands on two legs while picking the fruits which enables the animal to reach fruits on higher branches. When the chimpanzee has an armful (and mouthful) of fruits, it walks off on just two legs as it is using the hands and arms to carry more fruit. So the clip shows that bipedal behaviour also links to the ability to carry things while walking, which is linked to locomotion.

SAQ 18.1
The face became shorter and flatter during evolution from ape to human; Australopithecus has intermediate shape of face. Robusticity of the jaw increased from ape to Australopithecus but decreased from Australopithecus to Homo. The size of cheek teeth increased from ape to Australopithecus but decreased in Homo (Lewin, diagram, p. 99). Anterior tooth size decreased from ape to Australopithecus but increased in Homo. The first premolar in apes has one cusp, in humans has two cusps. The first premolar of Australopithecus is intermediate in shape between human and ape. Therefore skull and dentition of Australopithecus are intermediate between ape and human in some aspects, but not all.

SAQ 19.1
The fossils were found in the Tugen Hills in Kenya's Baringo district and included limb bones, teeth and a finger bone. Features of the arm and finger bones indicate that Orrorin was an agile tree climber.
The find is significant because Senut et al claim that features of the fossils indicate that Orrorin was bipedal. The evidence comes from the two left femora; both lack the greater trochanter. The femoral head is rotated slightly anteriorly. Senut et al claim that the intertrochanteric groove that runs from a small and deep trochanteric fossa to just above the lesser trochanter, provides evidence for bipedalism. However this evidence is not unequivocal.
The existence of a bipedal hominine 6 million years ago is of great significance. Before the Orrorin fossils were found, the oldest bipedal hominine was dated at 4.4 mya (Ardipithecus ramidus).

SAQ 20.1 (Objectives 20.1, 20.3)
Features of skull of Australopithecus robustus
-Males body mass- 40 kg: female body mass-32 kg (Lewin, Unit 20).
-Male height: 132 cm; female height: 110 cm (Lewin, Unit 20).
-Skull has sagittal crest (index card)
-Large flared zygomatic arches (cheek bones) that project forwards, hiding the nasal area (index cards).
-Central part of face strengthened by pillars of bone (Lewin, Unit 20; Hominid index, web links; index card)
-Foramen magnum relatively anterior (Hominid index, web links) skull structure shows attachment sites for 2 large chewing muscles, the masseter and the temporal (Lewin, Unit 20).
-Cranial capacity 530 cm3 (SK1585, a brain endocast, average cranial capacity for females ~500cm3 (Hominid index, web links).
-Tooth row tucked in under the face ( see image in News online, "Near complete ape-man skull found").
-Massive flat molar teeth; small blade-like incisors and canines (index card and Lewin, Unit 20)).

SAQ 21.1
Comparisons of anatomy between Australopithecus afarensis, Homo habilis, Kenyanthropus platyops and Homo (Kenyanthropus ) rudolfensis.

Australopithecus afarensis	Homo habilis	Kenyanthropus platyops	Homo rudolfensis
Brain ~380-450cm3	Small brain case; brain ~500 cm3	Small brain case	Fairly large brain case
Lower part of jaw is large and protruding	Small protruding face	Broad flat face	Broad flat face
Prominent brow ridges	Strong curved brow ridge	Flattened brow ridges	Slight brow ridge
Patterns of wear on teeth indicate fruit-eating	Patterns of wear on teeth indicate fruit-eating	Tooth wear suggests diet of hard seeds and nuts	Patterns of wear on teeth indicate fruit-eating
Diastema separates second incisor from the canine	No diastema present		No diastema present

The list of comparisons is not comprehensive; you may identify more.

SAQ 22.1
(a) Untrue. While it is correct that species can show variation in anatomy, this does not mean that 'lumping' of species together is always justified. Certain variations may indicate classification into separate species.3
(b) True.
(c) Untrue. Australopithecus afarensis is not the earliest hominine; earlier species include Australopithecus anamensis and Ardipithecus ramidus.
(d) Untrue, or most unlikely. The 'forest' of evolutionary trees on p, 128, indicates that earlier species, Ardipithecus ramidus and Australopithecus anamensis gave rise to Australopithecus afarensis. The earlier species were part of a bushy evolutionary tree so the true picture is likely to be more complex than those indicated by the forest of evolutionary trees.

SAQ 23.1
Fossilized bone tools associated with Australopithecus robustus were found in South Africa. L.Backwell and F.d'Errico, (Centre National de la Recherche Scientifique, Talence, France), compared scratch marks on the bones with marks on bones used for digging termites out of their nests and discovered that the marks matched. The researchers concluded the bone tools were probably used by A.robustus for digging out termites. South African Australopithecus robustus are dated at 2.0-1.0 mya.

SAQ 23.2
The Bossou chimpanzees use hammerstones and anvils to smash open the hard shells of palm nuts to gain access to the nutritious kernel inside the shell. The chimpanzees search for appropriate stones but do not modify them in any way, so they are not making tools. In contrast Oldowan stone tools were made by percussion knapping, from selected stones. Percussion knapping is a sophisticated technique that could not be mastered even by the intelligent bonobo, Kanzi.

SAQ 24.1
The URLs are:
http://www.mnh.si.edu/anthro/humanorigins/whatshot/2000/wh20004.html
http://www.archaeologytoday.net/web%20articles/082901-dmanisi_skulls.htm

In 1999 two almost complete Homo ergaster skulls were found at Dmanisi in sediment dated 1.75 mya by paleomagnetism. Argon-40/argon-39 dating of the basalt layer underlying the sediment gave an age of 1.85 mya. The Dmanisi finds suggest that Homo ergaster left Africa soon after its origin; the earliest African find of Homo ergaster/ erectus, KNM-ER 3733, is dated at 1.8mya. Whether Homo ergaster gave rise to Homo erectus in Asia and Europe or waves of migration of Homo erectus from Africa subsequently colonized Asia and Europe cannot be deduced from the new evidence. The find of Oldowan stone tools made of local basalt, associated with the Dmanisi skulls is significant because it shows that Homo migrated out of Africa before emergence of Acheulean stone tool technology. The conclusion is that Homo did not need Acheulean technology skills for migration. Homo ergaster migrated out of Africa and took their Oldowan technology skills with them.

SAQ 25.1
To make an Oldowan flake, a stone or cobble was hit once by a hammer stone to chip off a flake-this is percussion stone knapping. Many flakes can be struck from a stone core. The flakes are thought to have been the principal tools. Core forms left after knapping could also have been used as tools. Percussion knapping requires skill, in selecting the stone, and in judging the angle and intensity of the blow from the hammerstone.
In contrast to Oldowan tools, Acheulean stone tools had bifacial cutting edges. Large stones were selected or broken off boulders, and chipped repeatedly from two sides to produce a bifacial cutting edge. The cutting edge was refined further by bone or antler tools. The teardrop shaped handaxe would have required a high degree of cognitive ability to conceptualise the product, and to plan how to make it.

SAQ 26.1
Rowlett et al found an arc of basin-shaped reddish patches close to the old Lake Turkana and suggested they were ancient fireplaces. They identified phytoliths in the patches, microscopic pieces of silica found in plant cells. Of 4 red patches at Koobi Fora, 3 contained phyoliths from palm wood and other plants. Rowlett et al concluded that the red patches at Koobi Fora are ancient camp fires. Chert stone flakes found at the site were blackened showing effects of being heated in a fire; the flakes could have been used to make sparks to start the fires. A serrated stone cutter found in one of the fireplaces showed wear, indicating use for cutting soft tissues. Bones found at the site have cut marks. The finds suggest the site was used as a camp by hominines, probably Homo ergaster/erectus. The cranium, KNM-ER 3733 attributed to Homo ergaster, was found at Koobi Fora.

SAQ 27.1
Gorham's cave (Gibraltar) was occupied by Neanderthals between about 45-30 000 years BP. Mousterian stone tools, a hearth, and animal bones, have been found. Large blade-like flakes, Levallois technology, were found in the oldest layers. Fossils found in the cave suggest the Neanderthals were eating plants, intertidal molluscs, birds, small and large mammals. Ibex and Hermann's tortoise bones have cut-marks, indicating the Neanderthals were using their Mousterian tools for processing meat. Charred pine seeds and a hearth show that fire was used. In Vanguard cave, a charred layer has been found containing burnt mussel shells indicating that the Neanderthals were cooking. Cut-marked and burnt ibex bones have also been found. The evidence suggests that small groups of Neanderthals were using the caves as home bases, to which they brought food for processing cooking and eating. The fossil remains of plants and animals indicate that Neanderthals in Gibraltar had a varied diet.

SAQ 28.1
Neanderthal fossils found at Tabun and Kebara were initially dated at 60 000 years. Fossil skeletons of modern humans found at Skhull, and Qafzeh, Mount Carmel were thought to be more recent, dated at 40 000 years. These ages are consistent with the view that modern humans evolved from Neanderthals, supporting the multiregional hypothesis. Re-dating Neanderthal fossils from Tabun gave a mean age of about 120 000 years (Lewin, p168). Electron spin resonance gave a date of 122 000 years; uranium series dating of the sediment layer in which the Tabun fossils were found gave a date of 97 840 years; thermoluminescence dating gave a date of 171 000 years. The date of 60 000 years for the Kebara Neanderthals was confirmed by modern techniques. Re-dating modern H. sapiens fossils from Skhul and Qafzeh indicated an age of 100 000 years. The Skhull fossils were dated at 81-100 000 years by electron spin resonance and 119 000 years BP by thermoluminescence. The Qafzeh modern humans were re-dated at 96-115 000 years by electron spin resonance. The overlap of 40 000 years between modern humans and Neanderthals at Mount Carmel indicates that Neanderthals could not be the ancestors of H. sapiens, refuting the multiregional view and supporting the single origin hypothesis.

SAQ 29.1
(a) False. Types of mtDNA in human populations living today can be traced back to one female because of the dynamics of loss of mDNA over successive generations.
(b) True. The mtDNA of African people does show the greatest degree of variation, which is consistent with the view that modern humans originated in Africa. The finding does not prove that modern humans originated in Africa because it can be explained by the early African population being larger and hence more variable than other populations.
(c) True
(d) False. The weak Garden of Eden hypothesis states that the founding population of modern humans split into separate populations which later spread out to all parts of Africa, Asia and Europe to form the modern populations.
(e) True. Mismatch and intermatch distribution techniques support the view that populations of archaic Homo sapiens were replaced by immigrating anatomically modern humans.

SAQ 30.1
Blombos cave (Henshilwood, 2001) contains Middle Stone Age (MSA) layers, dated at 90-70 000 years BP, underlying an Aeolian dune complex dated at 70 000 years BP. The youngest stone artefacts, at least 70 000 years old, include pointed scrapers, lance-shaped bifacial tools and bone awls and points. 7 teeth attributed to modern humans, including one baby tooth, link the tools to Homo sapiens. Other finds in Africa suggest even earlier dates for modern human behaviour. Alison Brookes (George Washington University) described finds of barbed bone points at the Katanda site, Zaire, dated at 90-160 000 years old. The use of bone for tool making is regarded as a signature of modern human behaviour. To summarize it seems that technological signs of modern human behaviour appeared first in Africa. Modern human behaviour in Europe appears to be related to the arrival of anatomically modern human migrants around 40 000 years ago.
The evidence supports the 'out-of-Africa' model more strongly than the multiregional hypothesis.

SAQ 31.1
As the table shows, position of the lunate sulcus in australopithecines is debatable and therefore there is no agreement amongst researchers about when human-like brain organisation appeared. The marked increase in brain size with the emergence of Homo supports the view that human-like brain organisation began only with the origin of Homo.

Brain size and pattern in australopithecines and Homo.

	Australopithecines	Early Homo	Homo erectus/ ergaster	Archaic humans including Neanderthal	Modern humans
Brain size/cm3	400	650-800	850-1000	1100-1400	~1300
E.Q.	2.5	3.1	3.3		5.8
Relative sizes of lobes				Human-like, small occipital lobe	Parietal and temporal lobes predominate
Lunate sulcus	Position of lunate sulcus debatable (ref p. 192, Lewin)				Lunate sulcus further back than in ape

Overall there is not much information on the organization of the brain in australopithecines, early Homo, and Homo ergaster/erectus. You may be able to collect more information from the web and include this in your chart.

SAQ 32.1
The selective advantage of language ability may be linked to communication within a social group. Monkeys and apes have high intelligence but subsistence during their daily lives is not intellectually demanding. For primates living in groups the selective advantage of the ability to communicate may relate to the complexity of social interactions within a group. Social interactions include building up alliances within the group meaning that a physically weaker individual can triumph over a stronger challenger with the help of allies. This would apply to Homo too. Furthermore, for Homo, a meat eater, ability to communicate with other members of the group would improve co-operation during hunting.

SAQ 33 .1
The paintings include carnivores, a hyaena and a leopard, which was a surprise for those who studied Chauvet because carnivores are rare in other French caves. Other animals depicted in Chauvet include mammoth, bear, ibex, reindeer, bison rhinoceros and unusual yellow horse heads. Red dots are grouped in some of the chambers e.g. on a hanging rock close to the alcove that has the yellow horse heads. An unusual feature is that some of the animals are depicted as finger tracings in the soft putty-like outer layer of the cave wall e.g. a finger tracing of an owl, also of a horse. Human footprints were found and also evidence of hearths. Bones of cave bears are found in the cave too.

SAQ 33.2
Professor Henshilwood's team found many pieces of ochre in the cave and two of the pieces have a complex engraved patterns of criss-crossed lines. The engraved pieces of ochre were found in Middle Stone Age layers in the cave which are at least 70 000 years old. Professor Henshilwood interprets the engraving as a sign of modern human behaviour, occurring considerably earlier in Africa than in Europe.

SAQ 34.1
The arrival of Homo sapiens in Australia around 60 000 years ago (and probably earlier than this) is remarkable. Even though at that time the sea level was considerably below present levels as a result of the ice age, there was no land bridge between Australia and the land mass that is now the islands that include Indonesia. So, we have to conclude that 60 -70,000 years ago members of the genus Homo travelled by sea, in some way, to Australia. This is an astonishing feat and forces us to re-think our ideas about the abilities of Homo at that period.

SAQ 35.1
Archaeological excavations at the Kostenki site indicate a long period of occupation. The people of Kostenki were mammoth hunters. They chose the location, alongside the river Don, for their village because of the close proximity to water. Kostenki I, dated at about 24 000 years, comprises 2 settlements, each made up of pit dwellings with deep fire-hearths aligned up the centre. The people were burning mammoth bones in their fires.The pit dwellings were originally roofed with mammoth tusks and bones, which had fallen into the pits. Stone tools, bone needles and Venus figurines made of mammoth ivory have been found inside the pit dwellings.