{ "abstract": "Ancestral adaptive variation is thought to play an important role in facilitating adaptation to insular environments. However, to properly evaluate its role, we need to determine the age of genetic variation. In this study, we investigate the Iago sparrow (Passer iagoensis), a generalist endemic to the Cabo Verde archipelago, to understand how genetic diversity is maintained in an island lineage where populations are likely ephemeral and adaptation to environmental extremes is ongoing. Using whole-genome sequencing and phenotypic data, we inferred the species' evolutionary history, population structure, and signatures of selection. Our results show that the Iago sparrow diverged from its closest mainland relative approximately 4.26 million years ago, although the colonisation likely occurred only around 2 million years ago. Population structure analyses reveal three distinct lineages, corresponding to geographic divisions within the archipelago, with the Rombos islets population exhibiting significant phenotypic divergence, particularly in bill morphology. Genome scans and phenotypic measurements identified signatures of divergent selection in genes associated with bill size (HMG20B) and bill shape (ALX1), suggesting adaptive evolution in response to local environmental conditions. Our ancestral recombination graph analysis provided temporal estimates for adaptive variation associated with these genes, suggesting that adaptive haplotypes observed in the Rombos population arose after colonisation of the archipelago. This contrasts with patterns described in Darwin's finches, where ancestral variation likely originated prior to colonisation. Our findings highlight the interplay of genetic drift, gene flow, and selection in shaping island species' genetic diversity. The Iago sparrow, a generalist thriving across diverse habitats, provides insights into the mechanisms that maintain genetic diversity in island lineages despite small population sizes and pronounced environmental heterogeneity.", "abstract_shown": true, "affiliations": [ "Section for Ecology, Biodiversity and Evolution (EBE), Department of Biosciences, University of Oslo, Oslo, Norway.", "Department of Bioinformatics and Genetics, Swedish Museum of Natural History, Stockholm, Sweden.", "SciLifeLab, Karolinska Institutet Science Park, Solna, Sweden.", "CISAS-Center for Research and Development in Agrifood Systems and Sustainability, Polytechnic University of Viana do Castelo, Viana do Castelo, Portugal.", "Natural History Museum, University of Oslo, Oslo, Norway.", "Faculty of Biology, Ludwig Maximilian University Munich, Planegg-Martinsried, Germany.", "Museum of Vertebrate Zoology, University of California, Berkeley, California, USA.", "Department of Integrative Biology, University of California, Berkeley, California, USA.", "Escuela de Biología, Universidad de San Carlos de Guatemala, Ciudad de Guatemala, Guatemala.", "CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBio, Laboratório Associado, Universidade do Porto, Vairão, Portugal.", "Department of Animal Behaviour, Bielefeld University, Bielefeld, Germany.", "Bell Museum and Department of Ecology, Evolution and Behavior, University of Minnesota, Saint Paul, Minnesota, USA.", "Zooekologi, Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden.", "Department of Cell and Molecular Biology, National Bioinformatics Infrastructure Sweden, Science for Life Laboratory, Uppsala University, Uppsala, Sweden.", "Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK.", "Department of Evolution and Ecology, University of California, Davis, California, USA.", "Department of Molecular Biology and Biochemical Engineering, University Pablo de Olavide, Seville, Spain.", "Department of Biology, Lund University, Lund, Sweden.", "Institute of Vertebrate Biology, Czech Academy of Sciences, Brno, Czechia.", "Department of Zoology, Faculty of Science, Charles University, Praha, Czechia.", "STRIX - Innovation for Global Biodiversity, Alagoa Office & Retail Center, Carcavelos, Portugal.", "ICBAS, Instituto de Ciência Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal.", "Instituto de Engenharia e Ciências do Mar, Universidade Técnica do Atlântico, Mindelo, Cabo Verde.", "School of Life Sciences, University of Nottingham, Nottingham, UK.", "MHNC-UP, Natural History and Science Museum of the University of Porto, Porto, Portugal.", "FitzPatrick Institute of African Ornithology, University of Cape Town, Rondebosch, South Africa." ], "article_type": "research article", "arxiv": null, "author_total": 19, "authors": [ { "affs": [ 0, 1, 2 ], "name": "José Cerca", "orcid": "0000-0001-7788-4367" }, { "affs": [ 3 ], "name": "Ângela M Ribeiro", "orcid": "0000-0003-0666-3449" }, { "affs": [ 4, 5 ], "name": "Michael Matschiner", "orcid": "0000-0003-4741-3884" }, { "affs": [ 6, 7, 8 ], "name": "Rosa Alicia Jiménez", "orcid": "0000-0001-7048-730X" }, { "affs": [ 9, 10 ], "name": "Hugo Pereira", "orcid": "0000-0002-2108-9265" }, { "affs": [ 6, 11 ], "name": "Zheng Oong", "orcid": "0000-0002-8167-276X" }, { "affs": [ 12 ], "name": "Gabriel David", "orcid": "0009-0007-2935-3335" }, { "affs": [ 13 ], "name": "Per Unneberg", "orcid": "0000-0001-5735-3315" }, { "affs": [ 14 ], "name": "Yan Wong", "orcid": "0000-0002-3536-6411" }, { "affs": [ 15 ], "name": "Gabriele Maria Sgarlata", "orcid": "0000-0002-4115-6453" }, { "affs": [ 16, 17 ], "name": "Pim Edelaar", "orcid": "0000-0003-4649-6366" }, { "affs": [ 18, 19 ], "name": "Tomáš Albrecht", "orcid": "0000-0002-9213-0034" }, { "affs": [ 0 ], "name": "Glenn-Peter Saetre" }, { "affs": [ 9, 20 ], "name": "Pedro Cardia", "orcid": "0000-0003-3491-1331" }, { "affs": [ 9, 21 ], "name": "Augusto Faustino", "orcid": "0000-0003-2412-2013" }, { "affs": [ 22 ], "name": "Evandro P Lopes", "orcid": "0000-0003-3938-1560" }, { "affs": [ 6, 7 ], "name": "Rauri C K Bowie", "orcid": "0000-0001-8328-6021" }, { "affs": [ 0, 23 ], "name": "Mark Ravinet", "orcid": "0000-0002-2841-1798" }, { "affs": [ 9, 24, 25 ], "name": "Martim Melo", "orcid": "0000-0003-1394-4361" } ], "bibtex": "https://research.draconitic.com/paper/ch2f3pgs1znzv.bib", "cited_by": 0, "doi": "10.1111/mec.70587", "fulltext_url": "https://europepmc.org/articles/PMC13729259", "id": "ch2f3pgs1znzv", "issns": [ "0962-1083", "1365-294X" ], "landing_url": "https://europepmc.org/article/MED/42974965", "language": "eng", "licence": "CC-BY", "licence_label": "CC BY", "licence_source": "article", "licence_url": "https://creativecommons.org/licenses/by/4.0/", "metadata_licence": null, "native_subjects": [ [ "heading", "Original Article" ], [ "openalex", "1311|Genetic diversity and population structure" ] ], "openalex": "W7225167085", "pdf_url": "https://europepmc.org/articles/PMC13729259?pdf=render", "pmcid": "PMC13729259", "pmid": "42974965", "published": "2026-11-01", "publisher": null, "ris": "https://research.draconitic.com/paper/ch2f3pgs1znzv.ris", "sources": [ { "first_seen": "2026-11-04T15:20:47Z", "native_id": "MED:42974965", "source": "europepmc", "url": "https://europepmc.org/article/MED/42974965" }, { "first_seen": "2026-11-07T12:22:03Z", "native_id": "PMC13729259", "source": "pmc", "url": "https://doi.org/10.1111/mec.70587" } ], "subjects": [ { "field": "biology", "origin": "openalex:1311|Genetic diversity and population structure", "subfield": "genetics-genomics" } ], "title": "Dating the Colonisation and Source of Adaptive Genetic Variation in the Iago Sparrow (Passer iagoensis).", "title_text": "Dating the Colonisation and Source of Adaptive Genetic Variation in the Iago Sparrow (Passer iagoensis).", "type": "peer-reviewed", "updated_at": "2026-11-07T12:22:03Z", "url": "https://research.draconitic.com/paper/ch2f3pgs1znzv", "venue": "Molecular ecology", "versions": [] }