Trees before and after Darwin

Phylogenetic trees published before Darwin's On the Origin of Species are scarce. Lamarck (1809) and Barbancois (1816; J Phys Chim Hist Nat Arts 82, 444) are the first and only trees devoted to illustrating the genealogical connections between organisms of different species and different higher taxa. In the late 18th and early 19th centuries, most of the trees depicted in papers dealing with natural history were classifications; classifications in the shape of trees, but classifications nonetheless. Those published by Bronn (1858) are a good example. After Darwin, phylogenetic trees incorporating the time dimension flourished. In the first half of the 20th century, the Modern Synthesis failed to renew and rejuvenate the intuitive construction of trees. It wasn't until the appearance of Hennig's phylogenetic systematics that the real nature of the connection between phylogeny and the pre-Darwinian concept of homology was made clear.Resume Les arbres phylogenetiques publies avant L'Origine des especes de Darwin sont rares. Ceux de Lamarck (1809) et de Barbancois (1816) sont les premiers, et les seuls, a representer les liens genealogiques entre organismes et entre taxons de rang superieur. A la fin du 18e siecle et au debut du 19e siecle la plupart des arbres inclus dans des articles d'histoire naturelle etaient des classifications : des classifications en forme d'arbre, mais seulement des classifications. Les arbres publies par Bronn (1858) en sont un bon exemple. Apres Darwin les arbres phylogenetiques incorporant la dimension du temps se sont multiplies. La Synthese Moderne, au cours de la premiere moitie du 20e siecle, a echouea transformer la construction intuitive des arbres. Ce n'est finalement qu'avec la systematique phylogenetique de Hennig que l'on a eclairci la nature de la connexion entre la phylogenie et le concept pre-Darwinien d'homologie.