Resolution of the early placental mammal radiation using Bayesian phylogenetics

Science. 2001 Dec 14;294(5550):2348-51. doi: 10.1126/science.1067179.


Molecular phylogenetic studies have resolved placental mammals into four major groups, but have not established the full hierarchy of interordinal relationships, including the position of the root. The latter is critical for understanding the early biogeographic history of placentals. We investigated placental phylogeny using Bayesian and maximum-likelihood methods and a 16.4-kilobase molecular data set. Interordinal relationships are almost entirely resolved. The basal split is between Afrotheria and other placentals, at about 103 million years, and may be accounted for by the separation of South America and Africa in the Cretaceous. Crown-group Eutheria may have their most recent common ancestry in the Southern Hemisphere (Gondwana).

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Africa
  • Animals
  • Base Pairing
  • Bayes Theorem*
  • Biological Evolution
  • Cell Nucleus / genetics
  • Ecosystem
  • Fossils
  • Genes
  • Genes, rRNA
  • Likelihood Functions
  • Mammals / classification*
  • Mammals / genetics*
  • Markov Chains
  • Marsupialia / classification
  • Marsupialia / genetics
  • Mitochondria / genetics
  • Monte Carlo Method
  • Phylogeny*
  • Placenta
  • Probability
  • Sequence Analysis, DNA
  • South America