Complex sentence: Edmund Beecher Wilson (1856-1939) was an American geneticist and zoologist, he discovered the chromosomal XY sex-determination system in 1905, Nettie Stevens also decribed the system in 1905.
Split into simpler sentences: Edmund Beecher Wilson (1856-1939) was an American geneticist and zoologist. He also discovered the chromosomal XY sex-determination system in 1905, Nettie Stevens also decribed the system in 1905.