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

Abstract

Eulniur jidzw: a complex comprising six subspecies, is a classic example of species status conferred through evolutionary taxonomy. \Vc used the phylogcnctic species concept as an altrrnativc method to the biological species concept for determining historic patterns of gene flow between the various E. Ji/m sul)spccics and for conferring species status. In this paper, wc used population aggregation analysis to dctcrminc the proper species partitions and cladistic analysis to reconstruct the evolutionary rclationships of the different populations in the Eulmur,/i/z~ti.c complex. 1%'~sequenced three mtlIN.4 gene regions (d-loop, 12S, and cyt-11) and OIIC nuclear region, casein kiirasc, for R total of 1247 Imscs. Through population aggrrgation analysis, we determined that the E. fihlu., complex should he split into three units; one unit supported by six diagn tic sites comprising E.J: a/boco//fl7i\, ouc unit supportcd by thrcc diagnostic sites comprising f.. col/aii,s, and one unit supported by two diagnostic sites comprising the four other suhspccics. Although all six sul)species in the E.fuhw.\ complex share a commrin ancestor, WT found in our cladistic-analysis that E. J: collnri.~ and 6 ,/:nlbocollurir share a common ancestor that more recently split ofY from thc common ancestor of the fbur other E. ,fithu\ subspecies. 0 I W!l 'l'lrr I.iiiiiixii Sucirt\ 0 S 1.imd111~ AD1)ITIONAL KEY M'ORDS: --phylogcnctic and biological species concepts ~ evolutionary taxonomy ~ population aggregation analysis.

Lemur Diversity in Madagascar

“…Groves (2001) noted that the taxon has been set apart from other members of Eulemur fulvus based on its karyotype (2n=48; Petter et al 1977). It is also distinctly different from Eulemur collaris and E. fulvus with respect to molecular genetics (Wyner et al 1999). The southern limit of its distribution is probably the Mananara River.…”

“…Males are distinguished by a thick, elongated, cream to rufous beard; females also have a reddish beard, but it is significantly shorter than that of the males. Groves (2001) cited the unusually low (2n=50-52) and polymorphic chromosome number of this species (Buettner-Janusch and Hamilton 1979), and also the differences in fixed DNA sequences from other members of the genus demonstrated by Wyner et al (1999).…”

“…to full species, based on their distinct external appearances and craniodental characters (Tattersall and Schwarz 1991), as well as recent evidence for unique DNA sequences in E. collaris and E. albocollaris (cf. Djlelati et al 1997;Wyner et al 1999). Johnson et al (2008) concluded that albocollaris is a junior synonym for cinereiceps.…”

“…Obviously rivers do not coincide with the distributional limits of the taxa (Goodman and Ganzhorn, 2004;Irwin et al 2005). Even according to the preGroves taxonomy the 2 southern species of the Eulemur fulvus group (E. cinereiceps and E. collaris) seem genetically distinct enough from the other E. fulvus to warrant the status of distinct species (Djlelati et al 1997;Wyner et al 1999). Tattersall (1982) indicated that the range of Eulemur mongoz has been more widely misquoted than that of any other lemur.…”

Madagascar's Lemurs: Cryptic diversity or taxonomic inflation?

“…Echoing an earlier finding based on craniodental characteristics, 53 Wyner et al 54 used the analysis of three mtDNA regions to determine that the entire E. fulvus complex formed a single clade, a conclusion later supported by Yoder and Irwin. 55 Wyner et al 54 further combined phylogenetic and gene-flow analysis to reach the conclusion that the parapatric albocollaris and collaris populations (which, despite the fact that the females are virtually indistinguishable, are karyotypically very different, and do not produce fertile offspring 56 ) should be separated at the species level both from each other and from the other brown lemurs. At the same time, they recognized a high degree of interfertility among the remaining brown lemur taxa and reckoned that all four are best seen as subspecies of a single species.…”