August Weismann

Born in Frankfurt am Main on January 17, 1834, August Weismann became a German biologist, physician, and zoologist whose ideas had a lasting influence on evolutionary thought. He studied medicine at the University of Göttingen and later built his academic career in Freiburg, where he served as professor of zoology and directed the Zoological Institute.

Weismann is best remembered for developing the germ-plasm theory, which proposed that hereditary information is carried in reproductive cells and kept distinct from the rest of the body. That idea challenged the belief that traits acquired during an organism's lifetime could be inherited, and it made him one of the key thinkers linking Darwin's generation to the emerging science of genetics.

He died in Freiburg im Breisgau on November 5, 1914. Even though genetics developed further after his lifetime, Weismann's clear, bold arguments about heredity and evolution kept his name central to the history of biology.