THIS WEEK

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| NewScientist | 20 July 2013

BONES. That is all the passing millennia have left us of the Neanderthals and the more elusive Denisovans. Until recently, the main insights gleaned from these bones have been physical: what our cousins might have looked like, for instance, and how they moved. But cutting-edge genetic science is changing that. We can now see, for the first time, which genes are switched on in humans but were not in Neanderthals and Denisovans, and vice versa. The findings point to subtle differences between our brain structure and function, and theirs. The research, presented last week at the Society for Molecular Biology and Evolution meeting in Chicago, reveals that after our ancestors split from Neanderthals and Denisovans, they evolved differences in genes connected with cognitive abilities. Many of those genes are associated with mental disorders in modern humans. Working out which genes are switched on or not involves looking at the epigenome, or the chemical “methyl” tags attached to genes. Genomes, in contrast, show only the basic sequence of genes. Liran Carmel at the Hebrew University of Jerusalem, Svante Pääbo of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and colleagues analysed the epigenomes of Neanderthals and Denisovans and compared them with those of modern humans (s ee “What’s good about decay”, top right). Altered methylation patterns are frequently associated with disease, particularly cancer and mental disorders. So Carmel’s approach has the potential to give us unprecedented insight into the

– Dem bones got something to say –

The first look at which genes were switched on and off in our extinct cousins is allowing us to peer into their minds

Inside the brain of a Neanderthal

Sara Reardon, Chicago

“The approach could offer unprecedented insight into the mental abilities of extinct hominin species”