Phylogenetics
The Diprotodontia is the largest and most diverse of the marsupial orders comprising approximately 131 species of kangaroos, wombats, koalas, possums, and allies (Nowak, 1999). The order is divided into the suborders Vombatiformes and Phalangerida (Aplin and Archer, 1987). Vombatiformes comprises two super-families, Vombatoidea (wombats) and Phascolarctoidea (koala) while Phalangerida is more diverse, with five super-families, Macropodoidea (kangaroos, rat-kangaroos, and wallabies), Tarsipedoidea (honey possum and feather-tail possums), Phalangeroidea (brushtails and cuscuses), Petauroidea (gliders, striped possums, and ringtails), and Burramyoidea (pygmy possums). The last four superfamilies are often grouped as possums. The lineages comprising the Macropodoidea and Vombatiformes have each been consistently recognised as monophyletic by morphological characters and molecular data. In contrast, monophyly of the possums is not easily demonstrated by either morphological traits or by molecular evidence. We used mtDNA data from the ND2 gene from 31 species and available sequences from 12S RNA to reconstruct the phylogenetic history of the diprotondid marsupials. Phylogenetic analyses consistently identified monophyly for the Burramyoidea, Phalangeroidea, Petauroidea, Tarsipedoidea, Macropodoidea, and the Vombatiformes. Like previous molecular and morphological studies, relationships between the super-families were less well resolved.
Population Genetics
The mountain pygmy-possum, Burramys parvus, exists in isolated and fragmented populations in the Australian alps. To examine the degree of inter-population divergence, mitochondrial DNA sequences were obtained from samples representing all populations of B. parvus. Three divergent mitochondrial DNA (mtDNA) lineages were identified which exhibited strong phylogeographical structure. This indicates the presence of three maternal clades corresponding to populations in the northern, central and southern Australian alps. Molecular clock estimates suggest that the mtDNA lineages diverged from one another 420–680 thousand years ago. On this basis it is argued that B. parvus populations have probably been isolated since the mid-Pleistocene, and that management should focus on maintaining viable B. parvus populations in each of the three regional localities. Additional intra-population level studies were conducted in the Kosciuszko National Park population of mountain pygmy possums using the cytochrome b gene, which indicated low levels of genetic diversity and local population structure.
The Diprotodontia is the largest and most diverse of the marsupial orders comprising approximately 131 species of kangaroos, wombats, koalas, possums, and allies (Nowak, 1999). The order is divided into the suborders Vombatiformes and Phalangerida (Aplin and Archer, 1987). Vombatiformes comprises two super-families, Vombatoidea (wombats) and Phascolarctoidea (koala) while Phalangerida is more diverse, with five super-families, Macropodoidea (kangaroos, rat-kangaroos, and wallabies), Tarsipedoidea (honey possum and feather-tail possums), Phalangeroidea (brushtails and cuscuses), Petauroidea (gliders, striped possums, and ringtails), and Burramyoidea (pygmy possums). The last four superfamilies are often grouped as possums. The lineages comprising the Macropodoidea and Vombatiformes have each been consistently recognised as monophyletic by morphological characters and molecular data. In contrast, monophyly of the possums is not easily demonstrated by either morphological traits or by molecular evidence. We used mtDNA data from the ND2 gene from 31 species and available sequences from 12S RNA to reconstruct the phylogenetic history of the diprotondid marsupials. Phylogenetic analyses consistently identified monophyly for the Burramyoidea, Phalangeroidea, Petauroidea, Tarsipedoidea, Macropodoidea, and the Vombatiformes. Like previous molecular and morphological studies, relationships between the super-families were less well resolved.
Population Genetics
The mountain pygmy-possum, Burramys parvus, exists in isolated and fragmented populations in the Australian alps. To examine the degree of inter-population divergence, mitochondrial DNA sequences were obtained from samples representing all populations of B. parvus. Three divergent mitochondrial DNA (mtDNA) lineages were identified which exhibited strong phylogeographical structure. This indicates the presence of three maternal clades corresponding to populations in the northern, central and southern Australian alps. Molecular clock estimates suggest that the mtDNA lineages diverged from one another 420–680 thousand years ago. On this basis it is argued that B. parvus populations have probably been isolated since the mid-Pleistocene, and that management should focus on maintaining viable B. parvus populations in each of the three regional localities. Additional intra-population level studies were conducted in the Kosciuszko National Park population of mountain pygmy possums using the cytochrome b gene, which indicated low levels of genetic diversity and local population structure.