Available online
Description
This programme looks at the mating behaviour of the Ruff, the Picture Wings of Hawaii, Elephant Seals and Red Deer Stag as clear examples which demonstrate Darwin's theory on sexual selection. A fi...fth example, the common toad, is not such a clear example, and the programme includes some recent research on the mating behaviour of toads in an attempt to understand how these amphibians select their sexual partners.
This programme looks at the mating behaviour of the Ruff, the Picture Wings of Hawaii, Elephant Seals and Red Deer Stag as clear examples which demonstrate Darwin's theory on sexual selection. A fi...fth example, the common toad, is not such a clear example, and the programme includes some recent research on the mating behaviour of toads in an attempt to understand how these amphibians select their sexual partners.
| Module code and title: | S364, Evolution |
|---|---|
| Item code: | S364; 14 |
| First transmission date: | 17-09-1981 |
| Published: | 1981 |
| Rights Statement: | |
| Restrictions on use: | |
| Duration: | 00:24:30 |
| + Show more... | |
| Producer: | P. L Firstbrook |
| Contributor: | David Strong |
| Publisher: | BBC Open University |
| Keyword(s): | Darwinian theory; Evolution; Sexual selection |
| Footage description: | Film shots showing bird of paradise and red deer courtship behaviour. Commentary points out that both are illustrations of extreme sexual dimorphism. Film of mating behaviour of the common toad. Then, with the aid of a histogram, the commentary explains that a pattern of assortative mating is found here. Over a portrait of Darwin and illustrations from one of his books, commentary reviews his theory that fighting for females will tend to increase the size of males within a species while, where females choose their mates, the males will tend to develop bright and elaborate plumage.Darwin called these processes Intrasexual and Intersexual selection respectively. Film shots of Ruffs (birds related to Snipe and Curlew) during courtship and mating. The males of this species have very striking and elaborate plumage while the females are relatively drab. Several males display their plumage to a female who then chooses her mate; a clear example of intersexual selection. A histogram is also shown which indicates that some males are much more successful at attracting females than others. Film of another example of intersexual selection, this time among the picture winged drosophila of Hawaii. The film shows the male courting and then mating with a female. The programme goes on to consider examples of intrasexual selection where males fight each other to gain mating rights over females. As a first example, film shots of elephant seals during the mating season. Shots of males fighting and then copulating. Also brief shots of a female giving birth to a pup. A histogram shows that the largest males are the most successful at mating. Commentary points out the extreme sexual dimorphism found in this species. Another example of intrasexual selection is considered. Film shots of red deer during the rutting season. Shots of two stags fighting over a group of hinds. Commentary points to the antlers which are an example of sexual dimorphism.and confirm Darwin's theory. Shots of deer copulating. The programme goes back to look at toads mating in a pond. Commentary discusses whether either of Darwin's processes, Intrasexual and Intersexual selection, applies here. The male toads have developed neither bright markings nor great size and weapons. Commentary speculates on what the reasons for this are and what type of sexual selection may be operating here. |
| Master spool number: | HOU3528 |
| Production number: | FOUS119P |
| Videofinder number: | 2065 |
| Available to public: | no |
