Evolution by natural selection

SUMMARY: Professor M.J.Pentz interviews Dr. S.M. Manton who is involved in breeding cats. She shows some of the cats resulting from 8 generations of selection and inter- and cross-breeding, and explains some of the methods used in artificial selection. Dr. R.M. Holmes and Dr. M.E. Varley then illustrate the effect of natural selection on natural populations, by presenting some observations on the ratio of normal and melanic forms of peppered moth in industrial and non-industrial areas of Britain