Stages in the development of mammal embryos, 1905.
© Science Museum / Science & Society Picture Library
A lithograph from 'The Evolution of Man' by Ernst Haeckel (1834-1919), showing dog, bat, hare and human embryos at various stages of development. One of the first to sketch the genealogical tree of animals, Haeckel explained that the life history of the individual is a recapitulation of its historic evolution. Born in Potsdam, Haeckel became profesor of zoology at the University of Jena in 1862. One of the principal supporters of Charles Darwin's theories of evolution in Germany, he wrote broad-ranging books addresed to the general public and his illustrations inspired many artists. He is famous for his belief that the development of the individual recapitulates an organism's evolution ('Ontogeny repeats phylogeny').