*** Welcome to piglix ***

Nettie Maria Stevens

Nettie Stevens
Nettie Stevens.jpg
Born Nettie Maria Stevens
(1861-07-07)July 7, 1861
Cavendish, Vermont, United States
Died May 4, 1912(1912-05-04) (aged 50)
Baltimore, Maryland, United States
Education Westford Academy
Alma mater Westfield Normal School
Stanford University
Bryn Mawr College
Known for XY sex-determination system
Scientific career
Fields Genetics
Doctoral students Alice Middleton Boring
Influences Edmund Beecher Wilson
Thomas Hunt Morgan

Nettie Maria Stevens (July 7, 1861 – May 4, 1912) was an early American geneticist. In 1906, she discovered that male beetles produce two kinds of sperm, one with a large chromosome and one with a small chromosome. When the sperm with the large chromosome fertilized eggs, they produced female offspring, and when the sperm with the small chromosome fertilized eggs, they produced male offspring. This pattern was observed in other animals, including humans, and became known as the XY sex-determination system. .

Nettie Maria Stevens was born on July 7, 1861, in Cavendish, Vermont, to Julia (née Adams) and Ephraim Stevens. After the death of her mother, her father remarried and the family moved to Westford, Massachusetts. She graduated from Westford Academy in 1880.

Stevens taught high school and was a librarian. Her teaching duties included courses in physiology and zoology, as well as mathematics, Latin, and English. Her interest in zoology may have been influenced by taking a teacher training course on Martha's Vineyard in the 1890s.

After teaching for three terms, she continued her education at Westfield Normal School (now Westfield State University) completing the four-year course in only two years and being graduated with the highest scores in her class.

After graduation at the top in her class, she attended Stanford University, where she received her B.A. in 1899 and her M.A. in 1900. She also completed one year of graduate work in physiology under Professor Jenkins and histology and cytology under Professor McFarland. Stevens continued her studies in cytology at Bryn Mawr College, where she obtained her Ph.D. and was influenced by the work of the previous head of the biology department, Edmund Beecher Wilson, and by that of his successor, Thomas Hunt Morgan.


...
Wikipedia

...