Interspecific hybridization in pilot whales and asymmetric genetic introgression in northern Globicephala melas under the scenario of global warming

• Published in: PLOS ONE
• Main Authors: Miralles, Laura, Oremus, Marc, Silva, Monica A., Planes, Serge, Garcia-Vazquez, Eva
• Format: Article in Journal/Newspaper
• Language: English
• Published: Public Library of Science 2016
• Subjects: North Atlantic; Northeast Atlantic
• Online Access: https://hdl.handle.net/1912/8256

© The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in PLoS One 11 (2016): e0160080, doi:10.1371/journal.pone.0160080 . Pilot whales are two cetacean species (Globicephala melas and G. macrorhynchus) whose distributions are correlated with water temperature and partially overlap in some areas like the North Atlantic Ocean. In the context of global warming, distribution range shifts are expected to occur in species affected by temperature. Consequently, a northward displacement of the tropical pilot whale G. macrorynchus is expected, eventually leading to increased secondary contact areas and opportunities for interspecific hybridization. Here, we describe genetic evidences of recurrent hybridization between pilot whales in northeast Atlantic Ocean. Based on mitochondrial DNA sequences and microsatellite loci, asymmetric introgression of G. macrorhynchus genes into G. melas was observed. For the latter species, a significant correlation was found between historical population growth rate estimates and paleotemperature oscillations. Introgressive hybridization, current temperature increases and lower genetic variation in G. melas suggest that this species could be at risk in its northern range. Under increasing environmental and human-mediated stressors in the North Atlantic Ocean, it seems recommendable to develop a conservation program for G. melas. LM had a PCTI Grant from the Asturias Regional Government, referenced BP 10-004. MAS was supported by a 2013 FCT Investigator contract through POPH, QREN European Social Fund and the Portuguese Ministry for Science and Education. This study was also supported by a grant from the Principality of Asturias (reference: GRUPIN-2014-093).