Read Qiagen News Article | Read related PNAS paper

Speciation in Mouse Lemurs

Morphological analysis of mouse lemur populations, spanning a geographic range from Ankarana in the north to Beza Mahafaly in the south, had revealed the presence of three species new to science and warranted the resurrection of two others from synonymy (Rasoloarison et al., 2000).

We have conducted a molecular phylogenetic study using mtDNA to test the monophyletic status of individuals ascribed to the various species and to examine their hierarchical relationships. That analysis reinforced the hypothesis of species level status by confirming that each species is reciprocally monophyletic for mtDNA haplotypes (Yoder et al., 2000). The molecular analysis also suggested that several of the species show extremely limited geographic distributions, thus emphasizing their vulnerability to habitat destruction.

Considering these two studies jointly, it seems clear that species diversity in mouse lemurs has been considerably underestimated. Moreover, this conclusion, with the concomitant description of new species, is based on thorough data from only the western regions of Madagascar.

A field initiative has been launched, in collaboration with Rodin Rasoloarison (University of Antananarivo), Steve Goodman (University of Antananarivo), and Peter Kappeler (Deutsches Primatenzentrum, DPZ), to survey the eastern regions of Madagascar for mouse lemur diversity. At the same time, Kellie Heckman is developing independently segregating nuclear intron markers to test the hypotheses generated with the mtDNA data as well as to explore patterns of intra-specific population history.

Eventually, we will extend our studies to investigate functional regions of the genome that are potentially important for maintaining species boundaries.