The Englishman Charles Darwin is a scientist who needs no introduction. His pioneering work on evolutionary theory, outlined in the ‘Origin of Species,’ has informed scientific research and created public controversy since its publication in 1859. That he had a devotee in Germany, a 25-year-younger upstart by the name of Ernst Haeckel, was well-known to Darwin. Darwin and Haeckel met several times, exchanging ideas despite the language barrier. These meetings have been recalled in a blog post written by Ernst Haeckel’s great-great-granddaughter. That Ernst Haeckel was a respected scientist in his own right is evidenced by his inclusion as one of the few foreigners on the famous British deep sea expedition aboard the H.M.S. Challenger. Haeckel developed his own theories on organismal evolution based on his rigorous examination and illustration of samples collected on this expedition and others. His recapitulation theory, the idea that the embryonic development (ontogeny) of an organism is somehow reiterated in its evolutionary history (phylogeny), has been largely discredited with the advance of biological research. Although some of Haeckel’s scientific ideas have not withstood the test of time, his artistic contributions engage and inspire to this day. To learn more about Ernst Haeckel, check out this excellent article by Jennifer Frazer in Scientific American.