S3·E6 Peacocks, Parasites And The Puzzle Of Sex
Aired December 9, 1984
Synopsis
What's the purpose of sex? To protect us from disease! Brian Leith unravels the intricate puzzle of sex and finds that: Males seem to be a waste of time and energy - many of the successful plants and animals (like the weeds in your garden) do without them altogether! Big animals - from polar bears to human beings - always have males as well as females - for a very good reason! The vital clue to the mystery lies in parasitism and infection.
Out of the puzzle emerges a sparkling new theory of sex that looks set to keep biologists buzzing for years.