DNA barcoding and the study of incipient speciation in Neotropical birds

TUBARO, PABLO L.; BUKOWSKI, BELÉN; LIJTMAER, DARIO A.; CAMPAGNA, LEONARDO

Trondheim

Congreso; 8th International Barcode of Life Conference; 2019

Biodiversity Institute of Ontario

Background: The Neotropics constitute the most biodiverse region of the world, including over 3,000 bird species. The complex patterns of diversification of Neotropical birds, however, have been much less studied than in the Nearctic and the Palearctic, which is particularly true for the temperate south of South America. DNA barcoding of southern Neotropical birds showed that several species possess divergent intraspecific mitochondrial lineages, which constitute excellent cases to study the speciation process in the region. We are studying Vanellus chilensis (Southern Lapwing), Thamnophilus ruficapillus (Rufous-capped Antshrike) and Pipraeidea bonariensis (Blue-and-yellow Tanager). These species represent different avian radiations and have contrasting distributions and habitat preferences, thus allowing for the study of the different factors of diversification that have been proposed for the Neotropics. Results: Mitochondrial (COI + cytochrome b) patterns of divergence suggest that different factors acted in each species: the glacial cycles in V. chilensis (its main split is between Patagonia and the rest of South America), the Andes in the other two species (both show deep sequence differences along the Andes), and also the open vegetation corridor in T. ruficapillus (deep divergence between the Atlantic Forest and the Andes). These mitochondrial patterns are currently being studied in more depth using a genomic approach (ddradseq) to better assess the diversification history within each species, the level of gene flow among lineages and the role of the diversification factors mentioned above. We are also studying colouration and vocalizations, which could shed light on the process of phenotypic diversification in these taxa and help to elucidate whether some of these intraspecific lineages deserve species status. Significance: This study is increasing our knowledge about the patterns of evolution in the temperate Neotropics and shows that combining DNA barcoding scans with additional sources of genetic/genomic, morphological and behavioural information allows performing sound evolutionary studies.