American geneticist Nettie Stevens died #OTD in 1912.
In 1905, Stevens published a pivotal paper detailing her observations on the mealworm beetle, Tenebrio molitor. She identified that male mealworms had a pair of unequal-sized chromosomes, while females had two X chromosomes. This discovery supported the theory that sex is determined by specific chromosomes, a significant advancement in the field of genetics.
Books by Nettie Stevens at PG:
https://www.gutenberg.org/ebooks/author/35315