{
  "abstract": "Island radiations provide ideal frameworks for studying the molecular basis of convergent evolution. The rapid diversification of Dysdera spiders in Canary Islands provides a striking example, with repeated dietary shifts towards specialisation on woodlice, accompanied by morphological, metabolic, and behavioural modifications that facilitate the exploitation of this heavy-metal-rich prey. Here, we investigate two independent events of dietary specialisation on different islands. By analysing six high-quality genome-assemblies, including three newly generated in this study, we investigate the genomic signals of positive selection and relaxed selection in protein-coding genes, upstream regulatory regions, and gene family turnover rates. We detected signatures of positive selection associated with the two specialists, accompanied by a twofold increase in gene loss rates relative to generalist ancestors. Notably, positive selection targeted a smaller, functionally coherent set of genes, potentially involved in detoxification likely through heavy metal excretion. In contrast, relaxation of selection affected a broader set of genes associated with functions that may have become dispensable under the new dietary regime. Furthermore, we found contractions in gene families associated with vesicular transport, potentially reflecting a reduced reliance on vesicle-mediated metal accumulation. Overall, our findings suggest that similar ecological pressures can drive parallel, yet non-identical, adaptive and non-adaptive responses, pointing to partially predictable evolutionary trajectories in an island radiation.",
  "abstract_shown": true,
  "affiliations": [
    "Universitat of Barcelona"
  ],
  "article_type": "New results",
  "arxiv": null,
  "author_total": 8,
  "authors": [
    {
      "name": "M. Olive-Muniz"
    },
    {
      "name": "V. A. Pisarenco"
    },
    {
      "name": "N. Macias-Hernandez"
    },
    {
      "name": "C. Frias-Lopez"
    },
    {
      "name": "M. A. Arnedo"
    },
    {
      "name": "A. Sanchez-Gracia"
    },
    {
      "name": "S. Guirao-Rico"
    },
    {
      "affs": [
        0
      ],
      "name": "J. Rozas"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/3yzmh8t9xsb63.bib",
  "cited_by": 0,
  "doi": "10.64898/2026.11.05.764531",
  "fulltext_url": "https://www.biorxiv.org/content/10.64898/2026.11.05.764531v1.full",
  "id": "3yzmh8t9xsb63",
  "issns": [],
  "landing_url": "https://www.biorxiv.org/content/10.64898/2026.11.05.764531v1",
  "language": null,
  "licence": "CC-BY-NC",
  "licence_label": "CC BY-NC",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by-nc/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "biorxiv",
      "evolutionary biology"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://www.biorxiv.org/content/10.64898/2026.11.05.764531v1.full.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-05",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/3yzmh8t9xsb63.ris",
  "sources": [
    {
      "first_seen": "2026-11-07T00:21:24Z",
      "native_id": "10.64898/2026.11.05.764531",
      "source": "biorxiv",
      "url": "https://www.biorxiv.org/content/10.64898/2026.11.05.764531v1"
    }
  ],
  "subjects": [
    {
      "field": "biology",
      "origin": "biorxiv:evolutionary biology",
      "subfield": "evolutionary-biology"
    }
  ],
  "title": "Genomic signatures of positive selection and relaxed selective constraints associated with convergent dietary specialisation",
  "title_text": "Genomic signatures of positive selection and relaxed selective constraints associated with convergent dietary specialisation",
  "type": "preprint",
  "updated_at": "2026-11-08T00:21:09Z",
  "url": "https://research.draconitic.com/paper/3yzmh8t9xsb63",
  "venue": "bioRxiv",
  "versions": []
}