Startup Trying to Revive Woolly Mammoths Creates ‘Woolly Mouse’

Colossal Biosciences, a startup trying to bring the prehistoric mammoth back from extinction, said it has achieved a first step: the Woolly Mouse.

Using DNA and genomics technologies, scientists have modified the mice to have longer, thicker hair and an altered metabolism expected to allow them to tolerate colder temperatures, the startup said Tuesday — claiming a breakthrough in its mission to revive the long-extinct mammoth. The company said it’s on track to produce a woolly mammoth calf born to a surrogate elephant mother by late 2028.

“Woolly Mouse is not just a feat of engineering,” said Chief Executive Officer and co-founder Ben ...