Mouse Lemur Monologue

Hello.  My name is Anne, and I am addicted to mouse lemurs —- or perhaps I should say, to studying mouse lemurs, or maybe more specifically, to the genes of mouse lemurs. It all started back in the late 1990′s when I began a collaboration with my friend and colleague, Steve Goodman (Madagascar Field Biologist Extraordinaire).  Steve wrote to me, saying that he and a Malagasy graduate student, Rodin Rasolarison, were pretty certain that they had discovered as many as six new species of mouse lemurs in western Madagascar (at the time, there were only three species recognized by scientists in all of Madagascar).  Steve wanted to send me some genetic samples so that I could “prove” that they were new species.  Being very conservative on matters of species recognition, I assumed that it would all come to nothing, but at the same time, I couldn’t resist the offer of dozens and dozens of wild-caught genetic samples, so I dove in, and I haven’t looked back.

Fast forward to the present, and here I sit in London, still studying the genes of mouse lemurs.  Since that fateful day nearly 15 years ago, field activities and science have forged ahead, and it is now generally acknowledged that there are almost certainly 16 or more species of mouse lemurs!  Although most of the early evidence for this proliferation in species numbers has come from genetic data, scientists are delving ever deeper into the question of mouse lemur biodiversity, finding that mouse lemur species have subtle preferences for different foods and ecotypes, and also, that the males sing different species-specific mating calls to the females — much like is the case with various birds and insects.  As for me, I am stillstuck on the genetic side of things, and accordingly, I am looking into a set of genes that allow mouse lemurs (and other vertebrates) to recognize a rich bouquet of pheromones.  The thinking goes something like this:

As mouse lemurs species begin to diverge from one another, the members of the diverging species need to be able to recognize same-species partners from different-species partners. Theoretically, divergent pheromone signals might be a good way to do this.  Following this logic, natural selection will favor those individuals who are best able to discriminate same-species pheromones from those of different-species pheromones, which will then promote a process wherein there are more and more elaborate families of pheromone receptor genes.  So finally, we come to our hypothesis:  mouse lemurs (and perhaps, other nocturnal lemurs) will have considerably more elaborate pheromone receptor gene families than the other lemurs — or maybe not!  Stay tuned as my colleagues and I try to figure it all out.  Updates will follow!

– Dr. Anne D. Yoder

Director, Duke Lemur Center