Zink, R. M., Bell Museum, St. Paul, USA, zinkx003@umn.edu

NUCLEAR GENES AND TAXONOMIC LIMITS IN THE FOX SPARROW (PASSERELLA ILIACA).

Previous mtDNA studies of the fox sparrow revealed four historical taxa that correspond to plumage groups suggested by early naturalists to be separate species. Recently the use of mtDNA has come under attack because it represents a single gene tree, which could misrepresent evolutionary history for a number of reasons. The mtDNA pattern in fox sparrows was tested with five microsatellite loci. A resultant phenogram clustered most population samples for the red, sooty and thick-billed groups, whereas several populations from the slate-colored group were found within other groups. The most likely explanation is introgression, as the slate-colored group is flanked by all other groups. Because microsatellites possess many problems for phylogenetic analysis, several nuclear loci were sequenced. These loci confirm a lack of nuclear distinctiveness of the four groups. This result, however, does not challenge the historical status of the four groups. Because of the low mtDNA distances among groups, lack of reciprocal monophyly is predicted by coalescence theory. Thus, the nuclear loci confirm that the four groups are recently evolved and should not be interpreted as undermining their support.

Oral presentation

Session #:G47
Date: Wednesday, 8/6/08
Time: 4:00 PM

Presentation is given by student: No