"Stevens was born in Vermont in 1861 and got her start in science at the relatively late age of 35, when she had saved up enough to enroll in a small startup university in California. It was Stanford, and she thrived there, earning both a bachelor’s and a master’s degree by 1900.
After Stanford, Stevens pursued a PhD — a level of education very rare for women of her time — at Bryn Mawr in Pennsylvania. It was there that she turned her attention to solving the problem of sex determinism...
Stevens wanted to know how (and if) sex was passed on through genetic inheritance. She was making observations with a microscope of the chromosomes in Tenebrio molitor — the mealworm beetle — when she discovered something that had eluded humanity for millennia.
Stevens observed that the female mealworm’s cells had 20 large chromosomes. The male had 20 chromosomes as well, but the 20th was notably smaller than the other 19...
“It is generally stated that E. B. Wilson obtained the same results as Stevens, at the same time,” Brush writes. But “Wilson probably did not arrive at his conclusion on sex determination until after he had seen Stevens' results. ... Because of Wilson's more substantial contributions in other areas, he tends to be given most of the credit for this discovery.”
No comments:
Post a Comment