Document Type
Article
Keywords
adaptation, diversification, ecological niche, genomics, penguin
Abstract
The relative importance of genetic drift and local adaptation in facilitating speciation remains unclear. This is particularly true for seabirds, which can disperse over large geographic distances, providing opportunities for intermittent gene flow among distant colonies that span the temperature and salinity gradients of the oceans. Here, we delve into the genomic basis of adaptation and speciation of banded penguins, Galápagos (Spheniscus mendiculus), Humboldt (Spheniscus humboldti), Magellanic (Spheniscus magellanicus), and African penguins (Spheniscus demersus), by analyzing 114 genomes from the main 16 breeding colonies. We aim to identify the molecular mechanism and genomic adaptive traits that have facilitated their diversifications. Through positive selection and gene family expansion analyses, we identified candidate genes that may be related to reproductive isolation processes mediated by ecological thermal niche divergence. We recover signals of positive selection on key loci associated with spermatogenesis, especially during the recent peripatric divergence of the Galápagos penguin from the Humboldt penguin. High temperatures in tropical habitats may have favored selection on loci associated with spermatogenesis to maintain sperm viability, leading to reproductive isolation among young species. Our results suggest that genome-wide selection on loci associated with molecular pathways that underpin thermoregulation, osmoregulation, hypoxia, and social behavior appears to have been crucial in local adaptation of banded penguins. Overall, these results contribute to our understanding of how the complexity of biotic, but especially abiotic, factors, along with the high dispersal capabilities of these marine species, may promote both neutral and adaptive lineage divergence even in the presence of gene flow.
Publication Date
9-1-2024
Publication Title
Molecular Biology and Evolution
ISSN
07374038
E-ISSN
15371719
Volume
41
Issue
9
Original Article Number
msae166
DOI
10.1093/molbev/msae166
PubMed ID
39150953
Funding Number
RG_48_20
Funding Sponsor
Fondo Nacional de Desarrollo Científico y Tecnológico
Recommended Citation
León, Fabiola; Pizarro, Eduardo; Noll, Daly; Pertierra, Luis R.; Parker, Patricia; Espinaze, Marcela P.A.; Luna-Jorquera, Guillermo; Simeone, Alejandro; Frere, Esteban; Dantas, Gisele P.M.; Cristofari, Robin; Cornejo, Omar E.; Bowie, Rauri C.K.; and Vianna, Juliana A., "Comparative Genomics Supports Ecologically Induced Selection as a Putative Driver of Banded Penguin Diversification" (2024). Biology Department Faculty Works. 194.
DOI: https://doi.org/10.1093/molbev/msae166
Available at:
https://irl.umsl.edu/biology-faculty/194
