Phylogenomic reconstruction of sportive lemurs (genus Lepilemur) recovered from mitogenomes with inferences for Madagascar biogeography

Abstract

The family Lepilemuridae includes 26 species of sportive lemurs, most of which were recently described. The cryptic morphological differences confounded taxonomy until recent molecular studies; however, some species' boundaries remain uncertain. To better understand the genus Lepilemur, we analyzed 35 complete mitochondrial genomes representing all recognized 26 sportive lemur taxa and estimated divergence dates. With our dataset we recovered 25 reciprocally monophyletic lineages, as well as an admixed clade containing Lepilemur mittermeieri and Lepilemur dorsalis. Using modern distribution data, an ancestral area reconstruction and an ecological vicariance analysis were performed to trace the history of diversification and to test biogeographic hypotheses. We estimated the initial split between the eastern and western Lepilemur clades to have occurred in the Miocene. Divergence of most species occurred from the Pliocene to the Pleistocene. The biogeographic patterns recovered in this study were better addressed with a combinatorial approach including climate, watersheds, and rivers. Generally, current climate and watershed hypotheses performed better for western and eastern clades, while speciation of northern clades was not adequately supported using the ecological factors incorporated in this study. Thus, multiple mechanisms likely contributed to the speciation and distribution patterns in Lepilemur.