Scientists working to bring back the woolly mammoth have created genetically engineered mice that they say have several features of the extinct ice age giant.

The mice were created by Colossal Biosciences, which edits DNA for species conservation, and has been working to bring back the woolly mammoth since 2021.

The journey to the woolly mouse began with the woolly mammoth. Scientists at Colossal examined more than 100 genomes of Asian elephants and woolly mammoths. They lined up those genomes side by side and compared them to find the parts which are crucial for making a mammoth.

US company Colossal Biosciences has announced the creation of a "woolly mouse"—a laboratory mouse with a series of genetic modifications that lead to a woolly coat. The company claims this is the first step toward "de-extincting" the woolly mammoth.

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, Colossal Biosciences said.

This week, the world met the woolly “mammouse”—a genetically engineered mouse with woolly mammoth hair. The scientists at Colossal Biosciences who created it think it’s a promising step toward their goal of recreating the woolly mammoth.

While the Colossal Laboratories and Biosciences project to bring back extinct species has been compared to “Jurassic Park”, it has started at a much smaller scale than a T. Rex: woolly mammoth mice.