Aoudad RADSeq in Texas

Over the last century, Texas has been inundated with exotic ungulates, with perhaps as many as 67 species now represented by captive and free-ranging populations. One of the most successful species to have established free-ranging populations are aoudad (Ammotragus lervia). Herein, we expand on previous genetic studies in aoudad by including new genomic profiles based on double digest restriction site-associated DNA sequencing (RAD-seq) methods with the intent of better understanding the effects of > 70 years of human-mediated translocations, population expansion, and gene flow among populations. Using thousands of single nucleotide polymorphisms obtained from 73 individuals, we measured genetic patterns of diversity and connectivity between source populations from California and New Mexico and resultant aoudad populations in Texas. Principal components analyses identified phylogeographically structured populations across Texas. Further, we identified a signature of isolation by distance among Texas populations. To assess geographic regions that facilitated or blocked gene flow between populations, we used Estimation of Effective Migration Surfaces, which indicated three barriers to movement between populations as well as connectivity among populations in close proximity. Although A. l. blainei appeared to be genetically unique from the other subspecies, comparison of mtDNA haplogroups and nuclear genotypes were discordant indicating that the current subspecific taxonomic classification needs refinement. Given the vulnerable status of aoudad in their native range of northern Africa and the exponential population growth and competition with native ungulates in Texas, management and conservation efforts of aoudad need to maintain and preserve unique genetic units while minimizing competition and other detriments to native species.