In 2025, scientists successfully engineered 'woolly mice' using genes from what extinct animal?

In a remarkable scientific advancement in March 2025, researchers successfully engineered "woolly mice" by incorporating genes from the extinct woolly mammoth. This groundbreaking achievement was a significant milestone for Colossal Biosciences, a company dedicated to de-extinction efforts, particularly focused on bringing back a functional equivalent of the woolly mammoth. The creation of these mice served as a crucial proof-of-concept, demonstrating the ability to introduce and express traits characteristic of the ancient megafauna in a living organism.

The engineered mice exhibited several key traits associated with the woolly mammoth, including altered fur thickness, color, and texture, as well as adaptations for cold tolerance. Scientists meticulously studied the genetic code of woolly mammoths, comparing it with that of modern-day elephants, their closest living relatives. By identifying specific genes responsible for traits like long, shaggy hair and efficient fat metabolism, they were able to make targeted edits to mouse embryos using advanced gene-editing techniques. This process is not about creating an exact replica of the extinct animal, but rather engineering a cold-resistant elephant with the core biological traits necessary to thrive in Arctic environments.

This innovative research holds broader implications beyond simply recreating extinct animals. The techniques and knowledge gained from engineering these "woolly mice" are vital for advancing genetic technologies that could be used for conservation, potentially helping to preserve endangered species by restoring lost genetic diversity or enhancing their resilience to changing climates and diseases. The ultimate goal of the woolly mammoth de-extinction project is to reintroduce these animals to the Arctic tundra, where they could play a role in restoring the ecosystem and mitigating climate change.