Incongruence between genetic and morphological diversity in Microcebus griseorufus of Beza Mahafaly

Kellie L Heckman¹ , Emilienne Rasoazanabary² , Erica Machlin , Laurie R Godfrey² and Anne D Yoder³

¹Department of Ecology and Evolutionary Biology, Yale University, P.O. Box 208106, 165 Prospect St., New Haven, CT 06511 USA

²Department of Anthropology, 240 Hicks Way, University of Massachusetts, Amherst, MA 01003 USA

³Departments of Biology and Biological Anthropology & Anatomy, Duke University, Box 90338, Durham, NC 27708 USA

author email corresponding author email

BMC Evolutionary Biology 2006, 6:98doi:10.1186/1471-2148-6-98


Published:	16 November 2006

Abstract

Background

The past decade has seen a remarkable increase in the number of recognized mouse lemur species (genus Microcebus). As recently as 1994, only two species of mouse lemur were recognized according to the rules of zoological nomenclature. That number has now climbed to as many as fifteen proposed species. Indeed, increases in recognized species diversity have also characterized other nocturnal primates – galagos, sportive lemurs, and tarsiers. Presumably, the movement relates more to a previous lack of information than it does to any recent proclivity for taxonomic splitting. Due to their nocturnal habits, one can hypothesize that mouse lemurs will show only minimal variation in pelage coloration as such variation should be inconsequential for the purposes of mate and/or species recognition. Even so, current species descriptions for nocturnal strepsirrhines place a good deal of emphasis on relatively fine distinctions in pelage coloration.

Results

Here, we report results from a multi-year study of mouse lemur populations from Beza Mahafaly in southern Madagascar. On the basis of morphological and pelage variation, we initially hypothesized the presence of up to three species of mouse lemurs occurring sympatrically at this locality, one of which appeared to be undescribed. Genetic analysis reveals definitively, however, that all three color morphs belong to a single recognized species, Microcebus griseorufus. Indeed, in some cases, the three color morphs can be characterized by identical mitochondrial haplotypes.

Conclusion

Given these results, we conclude that investigators should always proceed with caution when using a single data source to identify novel species. A synthetic approach that combines morphological, genetic, geographic, and ecological data is most likely to reveal the true nature of species diversity.