{
  "abstract": "The struggle to explain the absence of evolutionary change in heritable, fitness-related traits of free-living populations has become emblematic of our ignorance of the evolutionary process in the wild. Yet while this ‘paradox of stasis’ has been the subject of much discussion, it is primarily identified a posteriori and rarely subject to direct quantification. We examined the evolution of clutch size in neighbouring populations of great tits (Parus major) before, during and after an experimental evolutionary perturbation. Interannual genetic changes in clutch size were directionally consistent with selection (refuting absolute stasis) but were smaller than predicted by adaptive evolutionary models (supporting relative stasis). Yet accounting for the contribution of post-selective immigration (i.e., explicitly recognising the distinction between adaptation and evolution) greatly improved our forecast accuracy and this tendency toward overprediction. Indeed, attributing interannual genetic change to its contributing demographic processes revealed immigration to be key to explaining periods of both evolutionary stasis and change, with its evolutionary impact varying across time and space in a manner analogous to the dynamism of natural selection. Our multi-decadal study of clutch size evolution thus shows that recognising the impact of gene flow is crucial to explaining contemporary evolutionary change and stasis of a key determinant of life history.\n\nWhy do we not see evolutionary change in heritable, fitness-related traits of free-living populations? This multi-decade study of the evolution of clutch size in populations of great tits before, during and after an experimental perturbation reveals the importance of gene flow in explaining contemporary evolutionary change and stasis.",
  "abstract_shown": true,
  "affiliations": [
    "Centre for Ecology and Conservation, University of Exeter, Penryn, United Kingdom",
    "Department of Animal Ecology, Netherlands Institute of Ecology, Wageningen, The Netherlands"
  ],
  "article_type": "Research Article",
  "arxiv": null,
  "author_total": 5,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Simon R. Evans"
    },
    {
      "affs": [
        1
      ],
      "name": "Henri Bouwmeester"
    },
    {
      "name": "Arie J. van Noordwijk"
    },
    {
      "name": "Marcel E. Visser"
    },
    {
      "name": "Erik Postma"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/450q52kk1v9hf.bib",
  "cited_by": 0,
  "doi": "10.1371/journal.pbio.3004004",
  "fulltext_url": "https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3004004",
  "id": "450q52kk1v9hf",
  "issns": [
    "1545-7885"
  ],
  "landing_url": "https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3004004",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "1105|Animal Behavior and Reproduction"
    ],
    [
      "plos",
      "/Biology and life sciences/Evolutionary biology/Evolutionary genetics"
    ],
    [
      "plos",
      "/Biology and life sciences/Evolutionary biology/Evolutionary processes/Evolutionary adaptation"
    ],
    [
      "plos",
      "/Biology and life sciences/Evolutionary biology/Evolutionary processes/Natural selection"
    ],
    [
      "plos",
      "/Biology and life sciences/Evolutionary biology/Population genetics"
    ],
    [
      "plos",
      "/Biology and life sciences/Genetics"
    ],
    [
      "plos",
      "/Biology and life sciences/Genetics/Population genetics"
    ],
    [
      "plos",
      "/Biology and life sciences/Physiology/Reproductive physiology/Oviposition/Clutches"
    ],
    [
      "plos",
      "/Biology and life sciences/Population biology/Population genetics"
    ],
    [
      "plos",
      "/Biology and life sciences/Psychology/Behavior/Animal behavior/Animal sexual behavior"
    ],
    [
      "plos",
      "/Biology and life sciences/Zoology/Animal behavior/Animal sexual behavior"
    ],
    [
      "plos",
      "/Research and analysis methods/Animal studies/Experimental organism systems/Animal models"
    ],
    [
      "plos",
      "/Social sciences/Psychology/Behavior/Animal behavior/Animal sexual behavior"
    ]
  ],
  "openalex": "W7213945122",
  "pdf_url": "https://journals.plos.org/plosbiology/article/file?id=10.1371/journal.pbio.3004004&type=printable",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-21",
  "publisher": "Public Library of Science",
  "ris": "https://research.draconitic.com/paper/450q52kk1v9hf.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:43Z",
      "native_id": "10.1371/journal.pbio.3004004",
      "source": "plos",
      "url": "https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3004004"
    }
  ],
  "subjects": [
    {
      "field": "biology",
      "origin": "plos:evolutionary biology",
      "subfield": "evolutionary-biology"
    },
    {
      "field": "biology",
      "origin": "plos:genetics",
      "subfield": "genetics-genomics"
    },
    {
      "field": "biology",
      "origin": "plos:animal behavior",
      "subfield": "zoology-behaviour"
    }
  ],
  "title": "Gene flow drives periods of both evolutionary stasis and change in a wild bird population",
  "title_text": "Gene flow drives periods of both evolutionary stasis and change in a wild bird population",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:17:43Z",
  "url": "https://research.draconitic.com/paper/450q52kk1v9hf",
  "venue": "PLOS Biology",
  "versions": []
}