The demands of managing life in a wide social group is one explanation for the development of intelligence. Chimps can handle a bigger group than Neanderthals, while humans can handle bigger groups than chimps © Getty Images

How can chimps share 98 per cent of our DNA and be so different?

With DNA, that two per cent difference is actually pretty high, especially considering how similar we actually are to our primate cousins.

Asked by: Ananda Singh, Southampton

Advertisement

I actually find it surprising that the difference is as much as two per cent, given how similar we are. Humans and chimps are roughly the same size, have the same number of arms, legs, fingers and toes. We are both warm-blooded, we have binocular, colour vision and hairy bodies. We suckle our young, laugh, fight with our fists and tickle each other. We are composed of the same kinds of cells, with the same membranes and mitochondria and ribosomes. We convert glucose from food and oxygen from the air into energy and exhale carbon dioxide.

Because all life on Earth is descended from a single common ancestor, much of the very basic cellular machinery is common to all living things – particularly among multicellular organisms. We share 85 per cent of our DNA with a zebrafish and 36 per cent with a fruit fly. Chimps and humans diverged from a common ancestor only around six million years ago. This is only about 0.13 per cent of the total history of life on Earth.

Chimps look so different from us, mostly because we are very good at spotting differences between things that are quite similar to us. Most people can’t distinguish a cod from a haddock, yet we have no difficulty telling an Ethiopian and an Inuit apart, despite them differing by less than 0.25 per cent of their DNA.


Advertisement

Subscribe to BBC Focus magazine for fascinating new Q&As every month and follow @sciencefocusQA on Twitter for your daily dose of fun science facts.