Nettie Stevens

Nettie Maria Stevens (July 7, 1861 – May 4, 1912) was an early American geneticist. She discovered sex chromosomes. 

Stevens saw two kinds of sperms in male mealworms. One had a large chromosome and one had a small chromosome. They were sex chromosomes, which later became known as the X and Y chromosomes.

Stevens eventually became fully qualified. She received a PhD in cytology, with Thomas Hunt Morgan as her advisor. She died from cancer. She had worked at Bryn Mawr College, Naples Zoological Station and the University of Würtzburg during her short career.

One paper, written in 1905, won Stevens an award of $1,000 for the best scientific paper written by a woman.N.M. Stevens 1905. A study of the germ cells of Aphis rosae and Aphis oenotherae. Journal of Experimental Zoology 2 (3):313–334.  Her major sex determination work was published by the Carnegie Institution of Washington in the two part monograph, Studies in Spermatogenesis.N.M. Stevens 1905. Studies in Spermatogenesis, with especial reference to the 'accessory chromosome'. Washington DC, Carnegie Institution of Washington, Publication 36. N.M. Stevens 1906. Studies in Spermatogenesis Part II. A comparative study of heterochromosomes in certain species of Coleoptera, Hemiptera, and Lepidoptera with especial reference to sex determination. Washington D.C. Carnegie Institution of Washington: Publication 36, Part II, 1906.

References

Category:1861 births
Category:1912 deaths
Category:American geneticists
Category:Scientists from Vermont