Int. J. Dev. Biol. 56: 653 - 660 (2012)
Karl Ernst von Baer (1792-1876) and Evolution
Essay | Published: 8 November 2012
Abstract
The research program of Karl Ernst von Baer (1792-1876) intended to enhance the comparative approach of animal classification by demonstrating vertebrate affinities (homology). Baer visualized his ideas on development and evolution with an unpublished figure of a branching tree. To buttress his reflections on how species-specific embryogenesis produces a branching tree, he worked out a cladogram-like chart, depicting the ontogeny and phylogeny of vertebrate embryos. For Baer, changes in development were responsible for changes in phenotype. I will offer a new interpretation of Baer’s ideas about evolution showing that he believed in the transformation of species and announced such views publicly.
Keywords
von Baer, history of developmental biology, evo-devo, hourglass model