Fresh analysis of Neanderthal genomes rules out inbreeding as cause of extinction

A sweeping new genetic study has upended one of the most persistent theories about why Neanderthals disappeared around 40,000 years ago. By analyzing more than two dozen Neanderthal genomes, researchers found that some of the last surviving groups maintained healthy levels of genetic diversity, suggesting that inbreeding was not the deciding factor in their demise. Science.org reported that the study, published in Nature, challenges the long-held idea that our closest cousins dwindled because of a shrinking, inbred population.

science.orgStudy of 25+ Neanderthal genomes suggests inbreeding did not cause their extinction

"some of the last surviving Neanderthals lived in genetically diverse, well-connected groups"

The analysis focused on high-quality genomes from specimens in north-western Europe, expanding what New Scientist called a genetic dataset that was previously limited mostly to Siberian individuals. This new geographic breadth reveals that Neanderthal populations on the western edge of their range remained well-mixed and genetically robust even in their final millennia.

"our closest cousins remained genetically healthy just before they vanished"

The finding shifts attention away from inbreeding and toward other possible drivers of extinction, such as competition with modern humans, rapid climate shifts, or demographic pressures that did not leave a clear genetic fingerprint. Science.org noted that the study adds a new twist to the enduring mystery of why Neanderthals perished after surviving hundreds of thousands of years in Eurasia through ice ages and harsh conditions.

New Scientist also highlighted that the results challenge the assumption that inbreeding was a major factor in the Neanderthals' extinction around 40,000 years ago. The implication, according to both outlets, is that the cause of their disappearance remains an open question, and future research will need to look beyond their DNA for answers.