Contemporary Europeans possess an excess of Neanderthal variants in genes involved in lipid catabolism, suggesting that Neanderthal DNA may have contributed to adaptations in modern humans. This finding, reported in a study published this week in Nature Communications, additionally suggests that European populations have as many as three times more lipid related Neanderthal genes that Asian and African populations.
Although Neanderthals are extinct, fragments of their genomes persist in modern humans. Yet it is currently unclear whether these shared regions occur constantly across the genome or if some regions are particularly enriched with Neanderthal variants. Philipp Khaitovich and colleagues show that DNA sequences shared between modern humans and Neanderthals are specifically enriched in genes involved in the metabolic breakdown of lipids - in order to release energy - and this sharing of genes is seen mainly in contemporary humans of European descent. They note that these sequences show signatures of recent positive selection which may indicate that these specific sequences give modern humans carrying the Neanderthal genotype a selective advantage.
The authors suggest that further work is needed in order to fully assess the potential functional effects that these shared, and possibly advantageous, DNA sequences infer.