Ernst Haeckel (1834 - 1919) was a professor of biology at the University of Jena, Germany. He was the first German advocate of Darwin's theory of evolution, and he formulated the often-repeated phrase "ontogeny recapitulates phylogeny." He was also the first to create a genealogical tree that related all of the various orders of animals. He published seven books, his last being The Riddle of the Universe.
