Ernst Haeckel

Ernst Heinrich Philipp August Haeckel (16 February 1834 – 9 August 1919) was an influential German zoologist, naturalist, and artist. He was also a philosopher and physician, but in those fields he is not regarded as particularly notable. He was an atheist. He left the Lutheran church in 1910. He is regarded as a pioneer of eugenics and Nazi eugenics in Germany.
Works.
Haekel was professor of comparative anatomy at the University of Jena, where he worked for 47 years, from 1862 to 1909. Haekel discovered, described and named thousands of new species, mapped a tree of life relating all life forms. He coined many terms in biology, including "ecology", "phylum", "phylogeny", "stem cell", and the kingdom "Protista." Haeckel promoted and popularised Charles Darwin's work in Germany and developed the controversial recapitulation theory ("ontogeny recapitulates phylogeny"). This claimed that an individual organism's biological development, or ontogeny, parallels and summarises its species' evolutionary development.
The published artwork of Haeckel includes over 100 detailed, multi-colour illustrations of animals and sea creatures. As a philosopher, Ernst Haeckel wrote "Die Welträtsel" (1895–1899, "The Riddle of the Universe", 1901), and "Freedom in Science and Teaching" to support teaching evolution.
Haeckel was a member of the nationalist and antisemitic Pan-German League (German: "Altdeutscher Verband") and of the peace organization Verband für internationale Verständigung.
Books.
Haekel wrote many books, some of them in multi-volumes. Among the most notable are: