INTROGRESSIVE HYBRIDIZATION AND NONCONCORDANT EVOLUTIONARY HISTORY OFMATERNAL AND PATERNAL LINEAGES IN NORTH-AMERICAN DEER

Introgressive hybridization between mule deer (Odocoileus hemionus) an d white-tailed deer (O. virginianus) was studied using sequence analys is of the paternally inherited, Y-linked, Zfy gene. The distribution o f Zfy genotypes indicate that male white-tailed deer disperse into the range of mule deer and successfully breed with mule deer does. In wes tern Texas, F-1 hybrids are rare, but a relatively high proportion of backcross individuals was observed. Phylogenetic analysis of Zfy among white-tailed, mule, and black-tailed deer was consistent with traditi onal systematic placement of the latter two being sister-taxa, whereas previous mtDNA studies suggested mule and white-tailed deer were sist er taxa.