Nettie Stevens

American geneticist

Nettie Maria Stevens (July 7, 1861 – May 4, 1912)[1] was an early American geneticist. She discovered sex chromosomes.

Nettie Stevens
Born
Nettie Maria Stevens

(1861-07-07)July 7, 1861
Cavendish, Vermont, United States
DiedMay 4, 1912(1912-05-04) (aged 50)
Baltimore, Maryland, United States
Cause of deathBreast cancer
EducationWestford Academy
Alma materWestfield Normal School
Stanford University
Bryn Mawr College
Known forXY sex-determination system
Scientific career
FieldsGenetics
InstitutionsBryn Mawr College, Carnegie Institution of Washington
ThesisFurther studies on the ciliate Infusoria, Licnophora and Boveria (1903)
Doctoral advisorThomas Hunt Morgan
Doctoral studentsAlice Middleton Boring
InfluencesEdmund Beecher Wilson
Thomas Hunt Morgan

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.[2]

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.[3] Her major sex determination work was published by the Carnegie Institution of Washington in the two part monograph, Studies in Spermatogenesis.[4]

References change

  1. "Nettie Stevens | American biologist and geneticist". Encyclopedia Britannica. Retrieved 2019-08-12.
  2. Brush, Stephen G. (1978). "Nettie M. Stevens and the discovery of sex determination by chromosomes". Isis. 69 (2): 162–172. doi:10.1086/352001. JSTOR 230427. PMID 389882. S2CID 1919033.
  3. N.M. Stevens 1905. A study of the germ cells of Aphis rosae and Aphis oenotherae. Journal of Experimental Zoology 2 (3):313–334.
  4. 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.