Thursday, June 7, 2018

[Mammalogy • 2018] Phylogenetic Analysis of the Tree-kangaroos (Dendrolagus) Reveals Multiple Divergent Lineages within New Guinea



Lumholtz's tree kangaroo (Dendrolagus lumholtzii), one of two species found in the wet tropics of north-east Queensland, Australia.  (Photo: N. Chaffer).

in Eldridge,  Potter, Helgen, et al. 2018.

Highlights
• DNA sequence data obtained from 14 of the 17 tree-kangaroo subspecies.
• Paraphyletic long-footed and monophyletic short-footed groups were identified.
• Six major genetic lineages were present, one in Australia and five in New Guinea.
• Episodes of diversification occurred during the late Miocene and Plio-Pleistocene.
• Species-level divergences within current taxa necessitate taxonomic adjustments.

Abstract
Amongst the Australasian kangaroos and wallabies (Macropodidae) one anomalous genus, the tree-kangaroos, Dendrolagus, has secondarily returned to arboreality. Modern tree-kangaroos are confined to the wet tropical forests of north Queensland, Australia (2 species) and New Guinea (8 species). Due to their behavior, distribution and habitat most species are poorly known and our understanding of the evolutionary history and systematics of the genus is limited and controversial. We obtained tissue samples from 36 individual Dendrolagus including representatives from 14 of the 17 currently recognised or proposed subspecies and generated DNA sequence data from 3 mitochondrial (3116 bp) and 5 nuclear (4097 bp) loci. Phylogenetic analysis of these multi-locus data resolved long-standing questions regarding inter-relationships within Dendrolagus. The presence of a paraphyletic ancestral long-footed and derived monophyletic short-footed group was confirmed. Six major lineages were identified: one in Australia (D. lumholtzi, D. bennettianus) and five in New Guinea (D. inustus, D. ursinus, a Goodfellow’s group, D. mbaiso and a Doria’s group). Two major episodes of diversification within Dendrolagus were identified: the first during the late Miocene/early Pliocene associated with orogenic processes in New Guinea and the second mostly during the early Pleistocene associated with the intensification of climatic cycling. All sampled subspecies showed high levels of genetic divergence and currently recognized species within both the Doria’s and Goodfellow’s groups were paraphyletic indicating that adjustments to current taxonomy are warranted.

Keywords: Marsupialia; evolution; biogeography; ancestral state; morphology

Lumholtz's tree kangaroo (Dendrolagus lumholtzii), one of two species found in the wet tropics of north-east Queensland, Australia.
(Photo: N. Chaffer).


....
Thus we recommend the recognition of 13 previously described taxa as species within Dendrolagus, two in Australia (lumholtzi, bennettianus) and 11 in New Guinea (inustus, ursinus, mbaiso, dorianus, notatus, stellarum, scottae, spadix, matschiei, pulcherrimus, goodfellowi). However, further changes to Dendrolagus taxonomy may occur as the result of ongoing studies and the addition of currently unsampled taxa. In the future we aim to utilize museum specimens to increase sample number and geographic coverage, as well as utilizing genomic approaches (e.g. Bi et al., 2013; Mason et al., 2011;  Rowe et al., 2011) to increase the data available to resolve relationships and elucidate evolutionary history.


Mark D.B. Eldridge, Sally Potter, Kristofer M. Helgen, Martua H. Sinaga, Ken P. Aplin, Tim F. Flannery and Rebecca N. Johnson. 2018.  Phylogenetic Analysis of the Tree-kangaroos (Dendrolagus) Reveals Multiple Divergent Lineages within New Guinea. Molecular Phylogenetics and Evolution. In Press. DOI: 10.1016/j.ympev.2018.05.030
Conservation genetics of tree-kangaroos

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