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By looking at the development and spread of Warfarian resistant rats and of copper tolerance in grasses, the programme examines the processes by which evolution by natural selection takes place.
Metadata describing this Open University video programme
Module code and title: S101, Science: a foundation course
Item code: S101; 19
First transmission date: 17-07-1979
Published: 1979
Rights Statement:
Restrictions on use:
Duration: 00:24:00
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Producer: Denis Gartside
Contributors: Jim Bishop; Anthony Bradshaw; Stephen Hurry; Colim Ingram
Publisher: BBC Open University
Keyword(s): Copper pollution; Warfarin
Subject terms: Environmental protection; Evolution; Grasses; Natural selection; Pollution; Rats
Footage description: Shots of rat traps being set and of rats running in straw. Commentary by Stephen Hurry discusses the introduction of the rat poison Warfarin in 1953. Over film shots of rat blood under the microscope, Hurry explains the mechanism by which Warfarin works. Excerpts from a 1958 BBC news programme shows an interview with a Ministry of Agriculture specialist who discusses the problem of the control of rats who have become resistant to Warfarin. Over shots of rats running in grassland and of rats in laboratory cages, Hurry and Jim Bishop (Liverpool University) discuss methods of studying the genetics of Warfarin resistance. Shots of a rat blood sample being tested for its ability to coagulate. An animated diagram illustrates the inheritance of the Warfarin resistance over two generations commentary by Stephen Hurry. Finally, an animal map of the UK shows the spread of Warfarin resistance among rats for the period 1958 to 1973. Shots of Parys Mountain in Anglesey. Shots of Tony Bradshaw on the mountain. He gives a brief history of the copper mining done here since Roman times. He also explains that copper is very toxic to plants and points to the lack of vegetation in the mining areas. Time lapse sequence compares the growth of young seed grasses in water with some in a copper solution. Tony Bradshaw then points out that even in the heavily copper polluted mine area one type of grass, Agrostic tenuis, still grows. He takes a sample of the soil under this grass for analysis. Shots of the above soil sample being analysed for copper content. Stephen Hurry outlines the procedure. Bradshaw then asks if it is possible that all grass of this species are copper resistant, time lapse sequence compares growth of young seedling in a copper solution from the mine area and from a pollution free area. Only the seedlings from the mine area are found to be copper resistant. Hurry and Bradshaw speculate on how this resistance of the grasses in the mine area might have come about. Time lapse sequence of grasses in a seed tray show the process in action. Bradshaw and Hurry describe and then perform an experiment to test if the copper resistance in Agrostictenuis is inherited. The results show that resistance is inherited. An experiment in which a smoke bomb simulates the spread of grass pollen demonstrates that the resistant grasses in the mine area can be pollinated by nonresistant grasses far away. Bradshaw explains why the resistant grass population at the mine does not become diluted as a result. Bradshaw goes on to explain why the grasses away from the mine, which are pollinated with pollen from the mine grasses, don't gradually become a resistant population. Over shots of areas in Anglesey heavily polluted by copper, Hurry and Bradshaw point out constructive uses for copper resistant plants. Stephen Hurry sums up the programme
Master spool number: 6HT/72913
Production number: FOUS019N
Videofinder number: 1194
Available to public: no