Nettie maria stevens biography of martin

She received her bachelor's degree inand her master's degree in Her master's thesis was published as Studies on Ciliate Infusoria a year later. InStevens return to the East to enroll in Bryn Mawr College as a graduate student in biology, a department dominated by two eminent faculty biologists, Edmund Beecher Wilson and Thomas Hunt Morganfuture Nobel laureate in genetics.

Stevens received her Ph. Stevens remained affiliated with Bryn Mawr as a Carnegie research fellow in biology from toand as an associate in experimental morphology from toduring which time she returned to work with Boveri from to As well, Bryn Mawr later endowed a research professorship for her. Stevens published widely in the fields of cytology and experimental physiology.

However, her most important contribution to science was the discovery that a particular chromosome was responsible for determining gender. At this time in scientific research, investigators were exploring the relationship between chromosomes and Gregor Mendel's laws of heredity, first described inbut no direct relationship had been confirmed by experiments.

Research up to this point had suggested only that a specific chromosome could be linked to a specific trait. InStevens first described, in an application for a Carnegie Institution grant, her research interest in this area. The same idea had been proposed, independent of her interests, by Edmund Beecher Wilson at Columbia University. Although the issue of priority in these two independent investigations has been questioned, it is accepted that the two came to the same conclusions separately from each other.

Stevens' paper, Studies in Spermatogenesis with Especial Reference to the Accessory Chromosomepublished in the Publications of the Carnegie Institution, described her observation of the common mealworm. The nuclei of the egg always contained ten large chromosomes but the spermatocytes could have either ten large or have one of the large chromosomes replaced by a small chromosome, referred to as X and Y chromosomes.

Stevens deduced that since a cell of the female contained 20 large chromosomes and the male had only 19 large chromosomes plus one small chromosome, this represented gender determination by a difference in the size of pairs of chromosomes. This theory was not universally accepted by other biologists. Stevens conducted additional research by observing other species of insects, and found further confirmation of her theory.

The discovery had a profound effect upon the study of genetics and the theory of gender determination when it ended the long debate over whether sex was determined by heredity or by environmental influence of the embryo. An esteemed research scientists, Stevens was also an inspiring and enthusiastic teacher. Before she could occupy the chair created for her by the trustees of Bryn Mawr, however, she died of breast cancer at Johns Hopkins Hospital in Baltimore in She was buried in Westfield, Massachusetts.

Bailey, Brooke. However, Stevens was not immediately recognized for her discovery on sex determination. For example, Morgan and Wilson were invited to speak at a conference to present their theories on sex determination inwhile Stevens was not invited to speak. This is despite the fact that Wilson acknowledged that Stevens had independently determined that the male mealworm beetle possesses dimorphism in spermatozoa before he had demonstrated it in nettie maria stevens biography of martin species in his paper published in December The Trustees of Bryn Mawr finally created a research professorship for Stevens, but she was never able to fill the position.

Despite the brevity of her career, Stevens contributed more to the field of genetics than many scientists with life-long careers. With at least 38 publications, Stevens was one of the first and few American women to be recognized for her contributions to scientific research at that time. While at Stanford and Bryn Mawr, Stevens faced the societal challenges of being a woman in science during a time when women were just starting to break through in science, and more specifically, the field of genetics.

Despite this, Dr. Nettie Maria Stevens left an indelible mark on the field of genetics, paving the way for future generations of women in science. Nettie Stevens Science and Innovation Center. While Stevens made groundbreaking contributions to the field of genetics, the Matilda Effect, a gender bias in the recognition of women's scientific achievements, impacted her legacy.

Stevens' discovery, differentiating the role of X and Y chromosomes in sex determination, was pivotal for genetics. By establishing that females possess two X chromosomes XX and males have one X and one Y chromosome XYher findings provided a crucial framework for understanding the genetic underpinnings of sex, influencing subsequent research and shaping the field of biology.

Additionally, in the article written by Morgan on her scientific work and contributions, Stevens was not given the title of her highest academic achievement, Ph. Nettie Stevens was no doubt a key contributor to unravelling the mysteries of cytology and heredity. We have authored and illustrated this entry with care and respect, aiming to achieve the highest standards through diligent, balanced research.

We also strive to maintain the highest standards of accuracy and fairness to ensure information is diligently researched and regularly updated.

Nettie maria stevens biography of martin: Nettie Maria Stevens was born on

Please contact us should you have further perspectives or ideas to share on this article. Brush, S. Nettie M. Stevens and the discovery of sex determination by chromosomes. Isis, 69 2— Choquette, C. Miko, I. Essentials of Genetics. Morgan, T. However, in the intervening decade prior to her death, she had managed to contribute more to her field than many scientists have with much longer careers.

This page appears in the eBook Essentials of Genetics, Unit 3. Key Questions How were sex chromosomes discovered? Key Concepts X chromosome sex chromosomes sex determination. Topic rooms within Genetics Close. No topic rooms are there. Browse Visually. Other Topic Rooms Genetics. Student Voices. Creature Cast. Simply Science.

Nettie maria stevens biography of martin: Nettie Maria Stevens, an

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Nettie maria stevens biography of martin: American geneticist who found

At 50 years old, and only 9 years after completing her Ph. Her career span was short, but she published approximately 40 papers. Her single-mindedness and devotion, combined with keen powers of observation; her thoughtfulness and patience, united to a well-balanced judgment, account, in part, for her remarkable accomplishment. Modern cytological work involves an intricacy of detail, the significance of which can be appreciated by the specialist alone; but Miss Stevens had a share in a discovery of importance, and her work will be remembered for this, when the minutiae of detailed investigations that she carried out have become incorporated in the general body of the subject.

To celebrate her th birthday, on July 7,Google created a doodle showing Stevens peering through a microscope at XY chromosomes. Contents move to sidebar hide. Article Talk. Read Edit View history. Tools Tools. Download as PDF Printable version. In other projects. Wikimedia Commons Wikidata item. American geneticist — Cavendish, VermontUnited States.

Baltimore, MarylandUnited States. Early life [ edit ]. Education [ edit ]. Career [ edit ]. Sex determination [ edit ]. Death [ edit ]. Quotes [ edit ]. Science, Vol. Legacy [ edit ]. See also [ edit ]. References [ edit ].

Nettie maria stevens biography of martin: Nettie Maria Stevens was,

Encyclopedia Britannica. Retrieved August 12, June Stevens and the Discovery of Sex Determination by Chromosomes". JSTOR PMID S2CID