Y of Sex

January 1, 2010-February 28, 2010
Location: Science & Technology Department

Did you know? Until the 1900s scientists could not answer the age-old question: Why was a person born male or female?

For time immemorial, myths, rumors, religions, and old wives tales had tried to answer the question. It was commonly believed that females determined (somehow) the sex of their children, and as a consequence, they were blamed, divorced and even executed for failing to produce male offspring (King Henry VIII is rumored to have had Anne Boleyn beheaded for not producing a male heir).

In 1905, Nettie Maria Stevens, an American scientist, was the first to discover that sex was determined by our chromosomes, namely, the Y chromosome that is only present in the genetic makeup of males. However, today's textbooks fail to mention Stevens and her discovery and assign credit to one of her male colleagues.

Visit SciTech's Y of Sex display and learn:

what a detailed map of all your 23 chromosomes look like
Stevens worked as a librarian for several years
Stevens obtained both her BS and MS degrees within 2 years at Stanford University
about the Stevens/Wilson controversy over who should be credited with discovering the chromosomal determination of sex
1.7% of human births are intersex (humans whose biological sex cannot be classified as either male or female)