Monito del monte (Dromiciops gliroides)
Evolutionary molecular systematics of vertebrates
Mitogenomic analyses suggest that the Chilean marsupial
monito del monte
Dromiciops gliroides),
formerly included in the American opossum family, is a closer relative to some Australian marsupials.
Dromiciops
occupies forrests, especially those containing Chilean bamboo. Image courtesy of and copyright Jaime E Jiménez.
All eutherian orders are by now represented by complete mt genomes. The unrooted molecular trees of eutherian relationships are essentially the same irrespective of whether the analyses have been based on mt data or nuclear data sets of reasonable size. However, the rooted trees differ in that the nuclear trees preferably place the root between the so-called African clade and remaining eutherians, while the mt analyses place the root between Erinaceomorpha (hedgehogs) and remaining eutherians, alternatively between Rodentia and other eutherian orders. An important issue in this discussion (e.g. Janke and Miazawa 2003) is the appropriateness of some protein-coding nuclear genes for phylogenetic analyses as their pattern of evolution may differ markedly from all acknowledged models for the evolution of such genes. Thus, the nuclear gene BRCA1, which is commonly used in phylogenetic analyses shows the same mutational rate for the three codon positions.
|
