Species concepts and the determination of historic gene flow patterns in the Eulemur fulvus (Brown Lemur) complex

Eulmur fulvus, a complex comprising six subspecies, is a classic example of species status conferred through evolutionary taxonomy. We used the phylogenetic species concept as an alternative method to the biological species concept for determining historic patterns of gene flow between the various E. fulvus subspecies and for conferring species status. In this paper, we used population aggregation analysis to determine the proper species partitions and cladistic analysis to reconstruct the evolutionary relationships of the different populations in the Eulemur fulvus complex. We sequenced three mtDNA gene regions (d-loop, 12S, anti cyt-b) and one nuclear region, casein kinase, for a total of 1247 bases. Through population aggregation analysis, we determined that the E. fulvus complex should be split into three units; one unit supported by six diagnostic sites comprising E f albocollaris, one unit supported by three diagnostic sites comprising E. f collaris, and one unit supported by two diagnostic sites comprising the four other subspecies. Although all six subspecies in the E fulvus complex share a common ancestor, we found in our cladistic analysis that E. f collaris and E f albocollaris share a common ancestor that more recently split off from the common ancestor of the four other E fulvus subspecies.