Louis Agassiz

Jean Louis Rodolphe Agassiz (May 28, 1807 – December 14, 1873) was a Swiss-born and European-trained biologist and geologist. His work on natural history in Europe and the Americas was important.
His reputation now is less good, because he fought against the theory of evolution, and held wrong ideas about human races. He thought the different human races were of different origins. This idea is called "polygenism". Darwin's comment at the end is interesting:
After visiting Harvard University in mid-career, he emigrated to the U.S. in 1847 and became a professor of zoology and geology at Harvard. He founded its Museum of Comparative Zoology.
Agassiz made extensive contributions to ichthyology (including extinct species). He founded glaciology, the study of ice fields and ice ages.