Take the case of the woolly mammoth. Colossal’s project aims to create a cold-adapted Asian elephant that can fulfil the mammoth’s former ecological role. But mammoths and Asian elephants diverged hundreds of thousands of years ago and differ by an estimated 1.5 million genetic variants. Editing all of these is, for now, impossible. Instead, scientists are targeting a few dozen genes linked to key traits like cold resistance, fat storage and hair growth.

Compare that to humans and chimpanzees. Despite a genetic similarity of around 98.8%, the behavioural and physical differences between the two are huge. If comparatively small genetic gaps can produce such major differences, what can we expect when editing only a tiny fraction of the differences between two species? It’s a useful rule of thumb when assessing recent claims.