Nettie Stevens: The Female Pioneer Who Unlocked the Science of Gender
Nettie Stevens, a pioneering cytogeneticist and researcher at Bryn Mawr College, discovered in 1905 that sex is determined by hereditary traits passed through chromosomes. She found that females are born with a pair of XX chromosomes, inheriting an X from both the mother and father, while males are born with XY chromosomes; the X is from the mother, the Y from the father. Stevens' discovery revolutionized the field of genetics and challenged the assumptions of many powerful people in biology. Despite her groundbreaking work, she did not receive credit for her discovery at the time due to her gender.