Health & Medicine
Fighting Sexism On Nettie Steven’s 155th birthday: Mother Of The XX/XY Chromosome
Jahra
First Posted: Jul 08, 2016 05:53 AM EDT
In this current age, we have so many gender classifications that the average person is left confused, but one thing is for sure, everyone is born into this world only as a girl or a boy. For thousands of years, we could only imagine why, but Nettie Stevens broke the code in her work at Bryn Mawr College.
Stevens singlehandedly debunked the greatest minds in times past including Aristotle who said that a man's body temperature during sex that determines the outcome.
18th century French anatomist Michel Procope-Couteau also promulgated the thought that "the best way to control a child's sex would be to remove the testes or ovary connected with the unwanted sex; though a less drastic mean for ladies would be to lie on the correct side, and let gravity do the rest,"
Thanks to Stevens It is now common knowledge that a child's sex is determined by the chromosomes that the father's sperm deposits into the mother. And in that union, XX sperms become women and XY become men.
And in honor of her work, here is a look back on how she discovered the importance of chromosomes in determining the sex of a child.
Stevens was one of the rare women who worked her way to Stanford and achieved a PhD in the early 1900s. She took the idea of the determination of sex as a hereditary matter from Gregory Mendel who had no audience for his theory at the time.
As the scientific community scrambled to find out how traits are passed between generations, Stevens set out to know whether and how sex is passed from generations.
It was when she was looking into the microscope at the chromosomes of the mealworm beetle (Tenebrio molitor) she discovered a fascinating difference between the male and the female. While both had 20 chromosomes each, one of the chromosomes in the male was much smaller than the rest and she wrote that this was a "clear case of sex determination."
She then traced the chromosomes back to the male mealworm sperm and reported that "The spermatozoa which contain the small chromosome [determine] the male sex, while those that contain 10 chromosomes of equal size determine the female sex."
Unfortunately for her, E.B. Wilsom published a similar result, but found the males lacking one chromosome, which is not a common occurrence in nature. It was his idea that gave the label X and Y chromosomes as he rode Mendel's theory that some genes are more dominant and override the instruction of their gene pairs.
While thy had similar results, he was not the first to conclude that this is the basis for sex determination and only concluded it after he saw Stevens' work.
And even though Stevens had the stronger case and a correct conclusion, Wilson got the credit due to his higher standing in the community and because he was male. It was another case of the "Matilda effect" where women's accomplishments are stolen or overshadowed by their male contemporaries.
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NASA's Juno Spacecraft's Rendezvous With Jupiter's Mammoth Cyclone
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First Posted: Jul 08, 2016 05:53 AM EDT
In this current age, we have so many gender classifications that the average person is left confused, but one thing is for sure, everyone is born into this world only as a girl or a boy. For thousands of years, we could only imagine why, but Nettie Stevens broke the code in her work at Bryn Mawr College.
Stevens singlehandedly debunked the greatest minds in times past including Aristotle who said that a man's body temperature during sex that determines the outcome.
18th century French anatomist Michel Procope-Couteau also promulgated the thought that "the best way to control a child's sex would be to remove the testes or ovary connected with the unwanted sex; though a less drastic mean for ladies would be to lie on the correct side, and let gravity do the rest,"
Thanks to Stevens It is now common knowledge that a child's sex is determined by the chromosomes that the father's sperm deposits into the mother. And in that union, XX sperms become women and XY become men.
And in honor of her work, here is a look back on how she discovered the importance of chromosomes in determining the sex of a child.
Stevens was one of the rare women who worked her way to Stanford and achieved a PhD in the early 1900s. She took the idea of the determination of sex as a hereditary matter from Gregory Mendel who had no audience for his theory at the time.
As the scientific community scrambled to find out how traits are passed between generations, Stevens set out to know whether and how sex is passed from generations.
It was when she was looking into the microscope at the chromosomes of the mealworm beetle (Tenebrio molitor) she discovered a fascinating difference between the male and the female. While both had 20 chromosomes each, one of the chromosomes in the male was much smaller than the rest and she wrote that this was a "clear case of sex determination."
She then traced the chromosomes back to the male mealworm sperm and reported that "The spermatozoa which contain the small chromosome [determine] the male sex, while those that contain 10 chromosomes of equal size determine the female sex."
Unfortunately for her, E.B. Wilsom published a similar result, but found the males lacking one chromosome, which is not a common occurrence in nature. It was his idea that gave the label X and Y chromosomes as he rode Mendel's theory that some genes are more dominant and override the instruction of their gene pairs.
While thy had similar results, he was not the first to conclude that this is the basis for sex determination and only concluded it after he saw Stevens' work.
And even though Stevens had the stronger case and a correct conclusion, Wilson got the credit due to his higher standing in the community and because he was male. It was another case of the "Matilda effect" where women's accomplishments are stolen or overshadowed by their male contemporaries.
See Now: NASA's Juno Spacecraft's Rendezvous With Jupiter's Mammoth Cyclone