Phylogeny of the Lemuridae: Effects of character and taxon sampling on resolution of species relationships within Eulemur

DNA sequences from three mitochondrial genes and one nuclear gene were anal yzed to determine the phylogeny of the Malagasy primate family Lemuridae. W hether analyzed separately or in combination, the data consistently indicat e that Eulemur species comprise a clade that is sister to a Lemur catta plu s Hapalemur clade. The genus Varecia is basal to both. Resolution of cladog enic events within Eulemur was found to be extremely problematic with a tot al of six alternative arrangements offered by various data sets and weighti ng regimes. We attempt to determine the best arrangement of Eulemur taxa th rough a variety of character and taxon sampling strategies. Because our stu dy includes all but one Eulemur species, increased taxon sampling is probab ly not an option for enhancing phylogenetic accuracy. We find, however, tha t the combined genetic data set is more robust to changes in taxon sample t han, are any of the individual data sets, suggesting that increased charact er sampling stabilizes phylogenetic resolution. Nonetheless, due to the dif ficult nature of the problem, we may have to accept certain aspects of Eule mur interrelationships as uncertain. (C) 1999 The Willi Hennig Society.