A glimpse into the mammal branch of the 'large' eukaryote tree

GIANNINI, NORBERTO PEDRO; GOLOBOFF, PABLO A.; CATALANO, SANTIAGO A.; MIRANDE, JUAN MARCOS; SZUMIK, CLAUDIA A.; ARIAS, J. SALVADOR; KÄLLERSJÖ, MARI; FARRIS, JAMES S.

San Javier, Tucumán

Congreso; A summit of cladistics. 27th Annual Meeting of the Willi Hennig Society and VIII Reunión Argentina de Cladística y Biogeografía; 2008

Willi Hennig Society

In a very recent development, Goloboff et al. (in phylogenomic studies. prep.) analyzed the largest phylogenetic dataset so far assembled in terms of taxonomic diversity and character representation for eukaryotes. Remarkably, most major eukaryotic clades were recovered. Mammals represent one prominent example. This group is important in this context because, rather unsurprisingly, it was best represented among all recovered clades in terms of both ingroup taxonomic diversity and sequence completeness. This study looks into the structure of the mam- malian subtree and compares its branching pattern with hypotheses of mammal phylogeny at several hierarchical levels. As with other major clades, but more strikingly so, the majority of currently recognized ordinal and familial relationships are accurately represented in the mammal subtree. The main structure of the mammal subtree, with a ca. 50-fold increase in taxonomic representation as compared with the most comprehensive previous molecular analysis, closely corresponds with many aspects of the current mammalian classification. But significantly, the dataset does not include a single gene used in recent higher-level phylogenetic studies of mammals. Group recovery is surprisingly accurate not only among major groups but at all taxonomic levels, including an exceedingly long list of monophyletic genera. We use the subtree to examine selected patterns of mammal evolution and discuss its implications.