A company that is trying to bring the woolly mammoth back to life has created woolly mice.

Colossal Biosciences tweaked the genes in mice embryos to make mice with long, thick hair (genes are found in all cells and control how the body grows and functions). The company calls its creation the “colossal woolly mouse”.

The next plan is to do the same to the embryos of Asian elephants, in the hope of achieving its big mission of recreating woolly mammoths for the modern world.

Asian elephants are the closest living relative of the woolly mammoth, but they’re still a very different species, having split onto a different evolutionary path (how species change over time) about six million years ago. They’re also endangered, so experimenting on their embryos would be difficult.

Colossal Biosciences claims that its work could help with animal conservation efforts. However, other scientists are critical.

Christopher Preston, a wildlife expert from the University of Montana, pointed out that the company isn’t actually achieving what it aims to. He told Sky News: “You might be able to alter the hair pattern of an Asian elephant… but it’s not bringing back a woolly mammoth. It’s changing an Asian elephant.”

Dr Adam Rutherford, a genetics lecturer from University College London, wrote in The Guardian that the project is “absurd” and “ghoulish”. He said that science should focus on protecting existing creatures instead.