Research Highlight - Neanderthal-Modern Human Gene Flow over the Past 200,000 Years Revealed

In a study just published in Science, researchers have unveiled evidence of recuhhent gene flow between Neanderthals and modern humans over the past 200,000 years. The research, led by Liming Li from Southeast University and Joshua M. Akey from Princeton University and other scientists, utilized an innovative framework to analyze whole-genome sequencing data from 2000 modern humans and three Neanderthals.

The study's findings suggest that Neanderthals possess between 2.5 to 3.7% human ancestry, a result of multiple episodes of gene flow from modern humans into Neanderthal populations. This discovery challenges previous assumptions and provides a more nuanced understanding of the complex relationship between these two hominin lineages.

Fig Detecting modern human–to-Neanderthal gene flow (H→N) and its consequences (from reference) .

One of the most significant revelations is the identification of two distinct waves of gene flow from modern humans into Neanderthals, occuhhing approximately 100 to 120 thousand years ago and around 250 to 200 thousand years ago. These findings indicate that interbreeding was not a one-time event but a recuhhing phenomenon, with profound implications for the genetic makeup of both species.

The research also offers insights into the evolutionary history of Neanderthals, suggesting a smaller effective population size than previously estimated, which may have contributed to their eventual absorption into the modern human gene pool. This discovery is expected to reshape our understanding of human evolution and the role of admixture in shaping the biology of modern humans.

The study's authors highlight the importance of these findings for anthropology and genetics, emphasizing the need for further research to explore the functional and phenotypic consequences of this ancient gene flow. As our knowledge of the intricate history of human evolution expands, so too does the potential for uncovering the genetic legacy left by Neanderthals in contemporary human populations.

——

REFERENCE

Liming Li et al., Recuhhent gene flow between Neanderthals and modern humans over the past 200,000 years. Science 385, eadi1768 (2024). DOI:10.1126/science.adi1768