Natural and Anthropogenic Influences on the Adaptive Potential of Large Mammal Isolated Populations.

Large mammals are charismatic species that have always interacted with the humankind, and lately this tendency is increasing because of their positive demographic trends in Europe. Management plans are necessary to regulate these interactions and they should consider the nature of the single populations, as selection and other evolutionary processes can happen at the local scale, leading to unique adaptations. The wild boar (Sus scrofa) and the wolf (Canis lupus) are two wide-spread, emblematic species of managerial interest. In Chapters 1, 2, 3, and 4 I have analyzed wild boar populations from many locations, including mainland Italy and the islands of Sardinia and Corsica, to describe the genomic diversity of these populations at the macroscale, and to investigate the effects of the local environmental conditions − including introgression from the domestic pig − on the genetic variability at the microscale. In Chapter 5 I focused on the evolutionary significance of the introgression of a dog-derived allele into the Italian wolf population. Sardinian and Italian wild boars were extremely differentiated from other European populations. The heterogeneity of past population histories and management approaches was mirrored by a variegated situation across the Italian peninsula. Signs of translocations from other European countries were negligible, thus contradicting the diffuse belief of massive substitution of the native wild boar; on the contrary, evidence of translocations within Italy was found and one of the best-preserved Italian populations (i.e. Castelporziano) seemed like one of the main source of re-stocking. The evolution of the wild boar on the two Mediterranean islands of Corsica and Sardinia, which led to classify the populations into a different subspecies (S. s. meridionalis), appears to be the result of adaptations developed on the islands in a short timeframe, with notable signs of selection at elements possibly implied in the regulation of gene expression, thus suggesting that various molecular tools are contributing to tweak the observed genetic and phenotypic distinctiveness. Both the Corsican and the Sardinian wild boars were interested by introgression from the domestic pig, with the former more than the latter when compared to a putatively pure population from mainland Italy. Focusing on the wild boar living on the island of Sardinia, I described the patterns of adaptation to local environmental conditions in an evolutionarily short period of time, as I found that the internal genetic differentiation can be partially attributed to differences in temperature and precipitation regime across the island. Furthermore, domestic introgression was not detected in a large number of samples, but I found compelling evidence of adaptive introgression at genomic regions of swine origin with a role in reproductive success. The positive influence on the fitness of wild populations with a domestic counterpart was demonstrated in the Italian wolf too, when focusing on the haplotype structure at the β-defensine gene carrying the dog-derived allele KB: the spread of this variant appears to be governed by trade-offs between survival and reproductive success. This thesis has demonstrated, with a population genomics approach, that even long-lived species like the two large mammals here considered can adapt to the local environmental conditions in short evolutionary timeframes, thus highlighting the importance of attentive evaluation by policy makers when it comes to the protection of biodiversity. The anthropic influence on the evolutionary trajectories of wild populations was treated and demonstrated in two of all its possible expressions: (un)documented past translocations for what concerns the wild boar, and wild x domestic hybridization for both the wild boar and the wolf, thus advocating for future monitoring campaigns that can take advantage of the several diagnostic genomic tools available to date.

Large mammals are charismatic species that have always interacted with humans. Many of these interactions deserve active management that should consider ongoing evolutionary processes including man-mediated selection and local adaptation. The wild boar (Sus scrofa) and the wolf (Canis lupus) are two widespread, emblematic species of managerial interest. Sardinian and peninsular Italian wild boars were differentiated from other European populations. The heterogeneity of past population histories and management approaches was mirrored by a variegated situation across the Italian peninsula. Signs of translocations from other European countries were negligible, while internal translocations possibly involving one of the best-preserved Italian populations as source were found. The evolution of the wild boar in Corsica and Sardinia, which led to the subspecies S. s. meridionalis, appeared to be the result of adaptations developed on the islands, with signs of selection at elements possibly implied in the regulation of gene expression. Focusing on the Sardinian wild boar, the genetic differentiation can be partially attributed to differences in temperature and precipitation regime across the island. Moreover, domestic introgression was not detected in several samples, but evidence of adaptive introgression at genomic regions of swine origin with a role in reproductive success emerged. The positive influence on the fitness of wild populations due to introgression from the domestic counterpart was demonstrated in the Italian wolf too: the spread of a dog-derived allele at a β-defensine gene appeared to be governed by trade-offs between survival and reproductive success. This thesis demonstrates, with a population genomics approach, that even long-lived species like the two large mammals considered can adapt to the local environmental conditions in short evolutionary time-frames and that different kinds of anthropic interference could have modified their evolutionary trajectories