Ernst Heinrich Philipp August Haeckel (February 16, 1834 – August 9, 1919), also written von Haeckel, was an eminent German biologist and philosopher. He promoted Charles Darwin's work in Germany and developed the theory that the organism's biological development, or ontogeny, parallels its species' evolutionary development, or phylogeny.
The published artwork of Haeckel includes over 100 detailed, multi-color illustrations of animals and sea creatures (see: Kunstformen der Natur, "Art Forms of Nature"). As a philosopher, Ernst Haeckel wrote Die Welträtsel (1895–1899, in English, The Riddle of the Universe, 1901), the genesis for the term "world riddle" (Welträtsel); and Freedom in Science and Teaching to support the teaching of evolution. (Full article...)