Center for Human Evolutionary Studies
The processes that drive reproductive isolation (RI) in cryptic species remain mysterious. Given that morphological and other phenotypic cues are usually fundamental to mate choice and successful reproduction in mammals, we wish to know why a species radiation might remain morphologically static (i.e., cryptic) while showing high levels of genetic and phylogenetic divergence. We are tackling this question by employing intensive field studies to examine behavioral, metabolic, genomic, and morphological characteristics in two species of cryptic mouse lemurs that occur sympatrically (and even syntopically) in Madagascar. Six months of intensive field investigation in both the reproductive and non-reproductive seasons indicate that the Microcebus murinus and M. griseorufus are partitioning their environment along multiple axes, including metabolic strategy. Ultimately, our study is one of the first to illuminate the RI continuum from genotype to phenotype in a cryptic primate radiation.
Jacinta Beehner, University of Michigan
