PhD defense by Germán Hernández Alonso

Title:

Population genomics reveals the pervasive role of genetic introgression in multiple wild-domestic species complexes.

Abstract:

"Genomic studies have revealed the high frequency of genetic introgression in vertebrate species and its evolutionary consequences. Human disruption and modification of natural habitats increase the opportunities for allopatric populations to meet and hybridise, including domestic and exotic invasive species; phenomenon that is considered of great concern in conservation biology. During my PhD, I developed three population genomic studies on different vertebrate species that show the extended presence of introgression. The first of them is a whole genome-based study about the domestic origin of the barbary dove. I was able to identify the African collared dove (Streptopelia roseogrisea) as the parental species of the domestic form, and I found recurrent genetic introgression from a closely related species, the Eurasian collared dove (S. decaocto). The second study aims at resolving the taxonomic status of the likely extirpated Korean wolves which, some argued, could represent an independent wolf lineage. Even though the results indicated that the Korean wolf is not distinct from other regional wolf populations, the analyses revealed regional wolf population structure patterns in East Asia with conservation potential on a regional scale. Additionally, the historical Korean wolf specimen used in this study showed strong signals of admixture with dogs, an observed pattern in other declining wolf populations. Finally, the last study describes the evolutionary history of the wild rock pigeons (Columba livia) using whole-genome sequencing data from 65 historical rock pigeons, including three specimens from Darwin’s collection and five type specimens. I identified high levels of divergence in the West African subspecies C. l. gymnocyclus. As an explanation, I proposed that such divergence could be the result of a long history of allopatry cycles during the Quaternary glacial and interglacial periods, supported by the signature of genetic introgression from C. rupestris into all the rock pigeons in our dataset, excluding the West African specimens."