Ernst Haeckel (1834-1919) was a German-born biologist, naturalist, evolutionist, artist, philosopher, and doctor who spent his life researching flora and fauna from the highest mountaintops to the deepest ocean. A vociferous supporter and developer of Darwin's theories of evolution, he denounced religious dogma, authored philosophical treatises, gained a doctorate in zoology, and coined scientific terms which have passed into common usage, including ecology, phylum, and stem cell.