Unraveling the origin of the wild pig (Sus scrofa Linnaeus, 1758) from the northwest Patagonian region: evidence of hybridization processes and a possible pure wild boar population in a protected area

Abstract

The wild boar (Sus scrofa) was introduced to Patagonia in the early 20th century through multiple independent events in Junín de los Andes, the Huemul Peninsula, and Victoria Island (Neuquén Province). Despite uncertainties surrounding their origin, questions persist regarding the extent of hybridization between these populations and domestic or feral pigs. This study presents (i) an analysis of the genetic variability and phylogenetic origin of the sub-Andean population (Neuquén province) of wild pigs from Patagonia using the molecular marker control region and (ii) a population genotyping with the MC1R marker to identify pure wild boar or domestic alleles in the zone. The results confirm the Iberian origin of the Patagonian wild pigs population and suggest potential genetic erosion due to genetic drift, as evidenced by low diversity values (Hd=0.7950±0.0510 and π=0.0036±0.0005) compared with previous studies from Argentina and Europe. Moreover, MC1R genotyping reveals the presence of hybrids in the region (allelic frequencies E+ = 0.5, EPD2 = 0.250, ED1e = 0.250), with a pure core observed on Isla Victoria, Nahuel Huapi National Park (allelic frequency E+ = 1). These findings are significant as hybrids contribute to the invasive potential of the species, a concern particularly pertinent in areas with protected habitats. Additionally, the identification of a pure wild boar population on Isla Victoria suggests its potential importance as one of the few remaining pure populations in the country.