The great apes – chimps, bonobos, orangutans and gorillas – are our closest relatives, genetically speaking. We share most of our genes with them, yet the remaining small differences can't account for the huge changes that separate us and our hairy relations. But, as the saying goes, it's not what you've got but what you do with it that counts. It's becoming clear that although we share most of our genes with apes, we use them in different ways. Scientists have discovered that patterns of DNA methylation – a kind of molecular 'tag' that tells genes to be switched off – are very different between apes and humans, even when the underlying genes are exactly the same. It's likely that these patterns, which affect when and where genes are turned on and off, lie at the heart of what separates us from the apes.
Written by Kat Arney
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