Evolutionary history of the Southern Lapwing (Vanellus chilensis) and the role of glaciations in its diversification

BUKOWSKI, BELÉN; CAMPAGNA, LEONARDO; RODRIGUEZ-CAJARVILLE, MARÍA JOSÉ; CABANNE, GUSTAVO S.; TUBARO, PABLO L.; LIJTMAER, DARÍO A.

London

Congreso; AOS & SCO?SOC 2023; 2023

American Ornithological Society (EEUU) y Society of Canadian Ornithologists

The evolutionary patterns of temperate South America, particularly in open habitats, have been less studied than in other areas of the Neotropics. We analyzed the evolutionary history of the Southern Lapwing (Vanellus chilensis), a widespread species characteristic of open habitats, as a case study to evaluate the continental-scale patterns and processes of diversification in the Neotropics, with a focus on Patagonia. We used two mitochondrial genes (COI and cyt b) and ddRADseq data from 58 individuals of the four subspecies of V. chilensis to perform a phylogenetic/phylogeographic analysis, and also studied their vocalizations (104 individuals). The initial diversification event within V. chilensis separated two lineages approximately 600,000 years ago, one of which is restricted to Patagonia. Genomic analyses indicated considerable gene flow between these two main lineages, supported a contact zone in northern Patagonia, and showed that genomic admixture extends to northwestern Argentina. A shallower divergence was detected between the two non-Patagonian subspecies, which are separated by the Amazon River. Vocalizations were significantly different between the two main lineages and were intermediate in the contact zone. Our results indicate that Patagonian populations of V. chilensis are clearly differentiated from the rest of the species, likely due to their isolation in refugia during the Pleistocene glaciations. The post-glacial, northward expansion of the Patagonian populations generated a secondary contact zone in northern Patagonia with extensive gene flow among lineages. Future analyses focused on the dynamics of the contact zone will allow us to establish whether the species continues to diverge or if its genome is homogenizing.