Journal of Mammalian Evolution

, Volume 2, Issue 1, pp 3–23

Phylogenetic relationships within the class mammalia: A study using mitochondrial 12S RNA sequences

  • Neil J. Gemmell
  • Michael Westerman

DOI: 10.1007/BF01464347

Cite this article as:
Gemmell, N.J. & Westerman, M. J Mammal Evol (1994) 2: 3. doi:10.1007/BF01464347


The interrelationships of the three mammalian groups, Monotremata, Marsupialia, and Eutheria, have been studied using DNA sequences from the mitochondrial 12S ribosomal RNA gene. The results suggest that the monotremes diverged from the living therians only shortly before eutherians and marsupials separated from each other, although there is some evidence for a slowdown in rate of base change in the monotreme lineage. Whtin the Monotremata, the two extant species of tachyglossids show a very close genetic relationship and the data suggest a very recent divergence. We have also confirmed that the Patagonian Monito del Monte,Dromiciops australis, is more closely related to the australidephian marsupials than it is to other South American species.

Key Words

12S rRNAmarsupialsmolecular evolutionmonotremesphylogeny

Copyright information

© Plenum Publishing Corporation 1994

Authors and Affiliations

  • Neil J. Gemmell
    • 1
  • Michael Westerman
    • 1
  1. 1.Department of Genetics and Human VariationLa Trobe UniversityBundooraAustralia