{
  "id": 5681086,
  "title": "Incipient speciation, rapid expansion and repeated introgressive hybridization in an African Giant Shrew (Crocidura olivieri)",
  "url": "https://urgent.news/2026/09/04/incipient-speciation-rapid-expansion-and-repeated-introgressive",
  "topic": "science",
  "section": "Science",
  "published": "2026-09-04T00:00:00.000Z",
  "source": {
    "name": "bioRxiv",
    "slug": "biorxiv",
    "url": "https://www.biorxiv.org/content/10.64898/2026.09.02.748917v1?rss=1"
  },
  "original_language": "en",
  "account": "The African giant shrew (Crocidura olivieri) exhibits a fascinating evolutionary history characterized by rapid diversification, hybridization, and demographic expansion. Through the analysis of genome-wide ddRAD and mitochondrial data from populations across sub-Saharan Africa, researchers have unraveled the complex genetic relationships within this widespread species. Mitochondrial and nuclear DNA evidence reveals extensive discordance, indicating that the clade's diversity is the result of multiple events rather than a single evolutionary process. The findings pinpoint three major evolutionary lineages, each associated with four instances of introgressive hybridization. Notably, ancestral lineages of the C. olivieri and arid-adapted species exchanged genomes extensively before later, unidirectional hybridization occurred to accompany range expansion. Within the C. olivieri group, five geographically distinct lineages exhibit ongoing gene flow, marking key stages of incipient speciation. Demographic studies further elucidate repeated population expansions during the Late Pleistocene and Early Holocene, with timings tied to climatic shifts and potentially influenced by human encroachment. The study underscores the significance of hybridization and range expansion as driving forces behind the diversification of African giant shrews, positioning this species as an exemplary model for exploring genomic mechanisms of early speciation.",
  "summary": "The African giant shrew (Crocidura olivieri) is one of the most widespread native small mammals in sub-Saharan Africa, occupying habitats ranging from humid tropical forests to arid Savanna. Its broad distribution, ecological diversity, and unresolved evolutionary relationships suggest a history of rapid diversification, yet the roles of hybridization and demographic expansion remain poorly…",
  "key_points": [],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}