A glimpse into the mammal branch from the "large" eukariote tree

GIANNINI, NP; GOLOBOFF, PA; CATALANO, S; MIRANDE, M; ARIAS, JS; KALLERJO, M; FARRIS, S

San Miguel de Tucuman

Congreso; Willi Hennig Meeting; 2008

Willi Hennig Society

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0in; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:ES-AR;} pre {margin:0in; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Courier New"; mso-fareast-font-family:"Times New Roman";} @page Section1 {size:8.5in 11.0in; margin:1.0in 1.25in 1.0in 1.25in; mso-header-margin:.5in; mso-footer-margin:.5in; mso-paper-source:0;} div.Section1 {page:Section1;} --> In a very recent development, Goloboff et al. (in prep.) analyzed thelargest phylogenetic dataset so far assembled in terms of taxonomicdiversity and character representation for eukariotes. Remarkably, mostmajor eukariotic clades were recovered. Mammals represent one prominentexample. This group is important in this context because, ratherunsurprisingly, it was best represented among all recovered clades interms of both ingroup taxonomic diversity and character data completeness. This study looks into the structure of the mammalian 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 c. 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 did 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 alltaxonomic levels, including an exceedingly long list of monophyleticgenera. We use the subtree to examine selected patterns of mammalevolution and discuss its implications.