Of lice and men: the return of the 'comparative parasitology' debate

The question of whether or not parasite phylogeny provides information about host relationships ('comparative parasitology') reached a peak in 1957 in a vigorous debate between Gunther Timmermann and Ernst Mayr. Timmermann argued that parasites were associated with their hosts by descent and that this produced congruent host and parasite phylogenies. In contrast, Mayr argued that parasites were often associated by colonization and that this led to incongruence between host and parasite phylogenies. To test these differing views, Adrian Paterson, Russell Gray and Graham Wallis derived a procellariiform phylogeny. This tree is here compared with Timmermann's tree based on the relationships of feather lice. Timmermann's tree is more similar to the seabird phylogeny that would be expected by chance. Thus, support is found for the 'comparative parasitology' approach.