Why does sex exist, and what is its purpose and function? What decides whether an individual will be male of female? How are chromosomes, genes, and molecules involved in determining sex? In four lectures, two leading scientists in the field of sex-determination research answer these questions.

Contains biographies of the lecturers, who discuss why they chose careers in science and what they enjoy most about their work. Lectures from Nov. 2001.

Lecture 1. Deciphering the language of sex -- lecture 2. Hermaphrodities, the safer sex -- lecture 3. Sex and death, too much of a good thing -- lecture 4. Sexual evolution, from X to Y.