Genomics, biogeography, and the diversification of placental mammals
- PMID: 17728403
- PMCID: PMC1958817
- DOI: 10.1073/pnas.0704342104
Genomics, biogeography, and the diversification of placental mammals
Abstract
Previous molecular analyses of mammalian evolutionary relationships involving a wide range of placental mammalian taxa have been restricted in size from one to two dozen gene loci and have not decisively resolved the basal branching order within Placentalia. Here, on extracting from thousands of gene loci both their coding nucleotide sequences and translated amino acid sequences, we attempt to resolve key uncertainties about the ancient branching pattern of crown placental mammals. Focusing on approximately 1,700 conserved gene loci, those that have the more slowly evolving coding sequences, and using maximum-likelihood, Bayesian inference, maximum parsimony, and neighbor-joining (NJ) phylogenetic tree reconstruction methods, we find from almost all results that a clade (the southern Atlantogenata) composed of Afrotheria and Xenarthra is the sister group of all other (the northern Boreoeutheria) crown placental mammals, among boreoeutherians Rodentia groups with Lagomorpha, and the resultant Glires is close to Primates. Only the NJ tree for nucleotide sequences separates Rodentia (murids) first and then Lagomorpha (rabbit) from the other placental mammals. However, this nucleotide NJ tree still depicts Atlantogenata and Boreoeutheria but minus Rodentia and Lagomorpha. Moreover, the NJ tree for amino acid sequences does depict the basal separation to be between Atlantogenata and a Boreoeutheria that includes Rodentia and Lagomorpha. Crown placental mammalian diversification appears to be largely the result of ancient plate tectonic events that allowed time for convergent phenotypes to evolve in the descendant clades.
Conflict of interest statement
The authors declare no conflict of interest.
Figures




References
-
- McKenna MC, Bell SK, Simpson GG. Classification of Mammals Above the Species Level. New York: Columbia Univ Press; 1997.
-
- Lecointre G, Le Guyader H. The Tree of Life: A Phylogenetic Classification. Cambridge, MA: Belknap Press of Harvard Univ Press; 2006.
-
- Donoghue MJ, Cracraft J. In: Assembling the Tree of Life. Cracraft J, Donoghue MJ, editors. Oxford, UK: Oxford Univ Press; 2004. pp. 1–4.
-
- Douady CJ, Chatelier PI, Madsen O, de Jong WW, Catzeflis F, Springer MS, Stanhope MJ. Mol Phylogenet Evol. 2002;25:200–209. - PubMed
Publication types
MeSH terms
Grants and funding
LinkOut - more resources
Full Text Sources