Browsing by Author "Kasinsky, Tatiana"

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    Genomic Introgression and Adaptation of Southern Seabird Species Facilitate Recent Polar Colonization
    (2025) Jorquera Faundez, Maria Josefina; Morales, Lucina; Ng, Elize Y.X.; Noll, Daly; Pertierra, Luis R.; Pliscoff, Patricio; Balza, Ulises; Boulinier, Thierry; Gamble, Amandine; Kasinsky, Tatiana; McInnes, Julie C.; Marin, Juan Carlos; Olmastroni, Silvia; Pistorius, Pierre; Phillips, Richard A.; Gonzalez-Solis, Jacob; Emmerson, Louise; Poulin, Elie; Bowie, Rauri C.K.; Burridge, Christopher P.; Vianna, Juliana
    Genomic adaptation and introgression can occur during the speciation process, enabling species to diverge in their frequencies of adaptive alleles or acquire new alleles that may promote adaptation to environmental changes. There is limited information on introgression in organisms from extreme environments and their responses to climate change. To address these questions, we focused on the 3 southern skua species, selected for their widespread distribution across the Southern Hemisphere and their complex history of speciation and introgression events. Our genomic data reveal that these skuas underwent diversification around the Penultimate Glacial Period, followed by subsequent demographic expansion. We identified a geographic region of introgression among species that followed a directional pattern sourced from the Antarctic continent, South America, and east to west in subantarctic islands, all converging towards the Antarctic Peninsula. The 3 skua species and admixed individuals exhibited a unique pattern of putative genes under selection, allowing adaptation to extreme conditions. Individuals with a higher proportion of Brown Skua ancestry showed signs of selection on genes related to reproductive isolation, while admixed individuals with a higher proportion of South Polar Skua ancestry displayed patterns resembling those of the South Polar Skua. Introgression may be a key mechanism of adaptation for many species that may help buffer against the ongoing climate change.
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    Population structure and connectivity among coastal and freshwater Kelp Gull (Larus dominicanus) populations from Patagonia
    (2024) Kasinsky, Tatiana; Rosciano, Natalia; Vianna, Juliana A.; Yorio, Pablo; Campagna, Leonardo
    The genetic identification of evolutionary significant units and information on their connectivity can be used to design effective management and conservation plans for species of concern. Despite having high dispersal capacity, several seabird species show population structure due to both abiotic and biotic barriers to gene flow. The Kelp Gull is the most abundant species of gull in the southern hemisphere. In Argentina it reproduces in both marine and freshwater environments, with more than 100,000 breeding pairs following a metapopulation dynamic across 140 colonies in the Atlantic coast of Patagonia. However, little is known about the demography and connectivity of inland populations. We aim to provide information on the connectivity of the largest freshwater colonies (those from Nahuel Huapi Lake) with the closest Pacific and Atlantic populations to evaluate if these freshwater colonies are receiving immigrants from the larger coastal populations. We sampled three geographic regions (Nahuel Huapi Lake and the Atlantic and Pacific coasts) and employed a reduced-representation genomic approach to genotype individuals for single-nucleotide polymorphisms (SNPs). Using clustering and phylogenetic analyses we found three genetic groups, each corresponding to one of our sampled regions. Individuals from marine environments are more closely related to each other than to those from Nahuel Huapi Lake, indicating that the latter population constitutes the first freshwater Kelp Gull colony to be identified as an evolutionary significant unit in Patagonia.