Thursday, September 10, 2009
Ernst Haeckel's house
During my recent trip to Jena, Germany, I saw an after-dinner talk by Olaf Breidbach that was held at Ernst Haeckel's old house. Above is a portrait of old Ernst himself.
His history is pretty checkered, especially as concerns his interpretations of evolution and developmental biology, but he did some nice natural history work that he documented with beautiful (if somewhat embellished) drawings.
We now know that one of his most famous ideas about evolutionary developmental biology, that "ontogeny recapitulates phylogeny", is not generally the case. However, there are some instances where the development of a structure within an animal does seem to pass through an intermediate stage that is more reminiscent of more basal species. In paper wasps, for example, mushroom body development begins with a structure that looks like that of most other hymenopterans (the ants, bees and wasps)(panels A, D and G above), but then reorganizes in the pupa (panels B, E, H) into a morphology that is unique to the higher paper wasps (C, F, I) (Farris, Abrams and Strausfeld, 2004). So in this rather unusual instance, ontogeny (development) does recapitulate phylogeny (the evolutionary history of the insect, in which wasps with these unique mushroom bodies arose from wasps with more typical hymenopteran mushroom bodies).
The talk was given in the dining room, which had this beautiful painting of one of Haeckel's cnidarians around the chandelier...
...and ended with this nice picture of Ernst's brain. Maybe someday people will be showing pictures of my brain in their talks, too...