Scientists at Colossal Biosciences have created genetically modified “woolly mice” with thick, wavy golden coats as part of their broader effort to bring back the extinct woolly mammoth. This development, announced in March 2025, represents what the company calls a significant step toward their goal of de-extinction. The experiment involved editing seven genes in laboratory mice, targeting traits such as hair length, texture, and fat metabolism. These modifications were designed to mimic characteristics that helped mammoths survive in cold environments thousands of years ago. “For us, it’s an incredibly big deal,” said Beth Shapiro, chief science officer at Colossal Biosciences. … Continue reading Colossal’s ‘Woolly Mice’ Created with 7 Gene Edits: A Step Toward Reviving Woolly Mammoths