Across two millennia, cats have lived alongside wildcats without mixing much. New findings published in Current Biology reveal that domestic and wild animals remained largely separate until roughly the 1960s, and even then interbreeding occurred only because wildcat populations had dwindled and habitats fragmented, leaving few options for free-ranging cats.
Researchers from the universities of Munich, Bristol and Oxford, together with the Royal Zoological Society of Scotland, based their conclusions on genetic analyses and archaeological discoveries. They examined ancient specimens uncovered at 85 sites dating back as far as 8,500 years to trace hybridization patterns as domestic cats, derived from the Middle Eastern wildcat Felis lybica, spread into Europe at least 2,000 years ago and encountered native European wildcats, Felis silvestris.
Evidence indicates that domestic cats and wildcats have coexisted for about two millennia, yet mating between the two remained rare. Europeans largely avoided interbreeding, even while sharing living spaces, with hybridization estimated to be around 10% in some contexts.
Scientists attribute this reproductive isolation to differences in behavior and ecology between the two species.
Everything changed in the 1960s
New observations show a marked rise in hybridization beginning in the 1960s. This shift is linked to a decline in feral cat populations caused by environmental pressures, which reduced opportunities for interbreeding among feral cats themselves.
As Jo Howard-McCombe of the University of Bristol and the Royal Zoological Society of Scotland noted, wild and domestic cats have recently exchanged genes primarily because habitat destruction and spreading human activity push wildcats toward the brink in many regions, elevating contact and potential interbreeding.
The increase in hybridization is tied to habitat loss and declining wildcat numbers
Regional analyses point to Scotland as having the highest rates of hybridization between wild and domestic cats, with the Iberian Peninsula following closely. In these areas, roughly a quarter of wildcat lineages show traces of domestic ancestry, signaling substantial genetic mixing in limited wild populations.
The wildcat remains a threatened European species, to such an extent that scientists speak of a silent extinction. Habitat loss, fragmentation, and prey scarcity are commonly cited drivers of its precarious status.
Over the last decade, genomic studies of both modern and ancient individuals have shown that as domestic cats spread into new regions, they interbred with closely related wild relatives, leaving lasting imprints on wildcat genomes. This pattern appears in many domestic animals, with the notable exception of dogs, where interbreeding dynamics differ.
Reference material for these conclusions includes contemporary and paleogenomic research published in Current Biology, with DOI 10.1016/j.cub.2023.08.031 and related full-texts. These sources summarize the genetic and archaeological evidence supporting the emergence, spread, and hybridization patterns of domestic cats and wildcats across Europe.
Endnotes: The environmental implications of these findings emphasize how human-driven habitat changes reshape species boundaries and gene flow across wild populations. These dynamics highlight the need for habitat restoration and wildlife corridors to reduce unintended interbreeding pressures and preserve the ecological integrity of wildcat populations.
Further reading and citations reflect the body of work on felid genetics and historical biogeography, bringing together genome sequencing, ancient DNA analysis, and archaeological context to illuminate long-term interactions between domestic and wild felids.
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