A woolly mouse, a breed created by scientists using genetic engineering. The development is a first step toward reviving a version of the extinct woolly mammoth. Colossal Biosciences Scientists have genetically engineered mice with some key characteristics of an extinct animal that was far larger — the woolly mammoth. This "woolly mouse" marks an important step toward achieving the researchers' ultimate goal — bringing a woolly mammoth-like creature back from extinction, they say. "For us, it's an incredibly big deal," says Beth Shapiro, chief science officer at Colossal Biosciences, a Dallas company trying to resurrect the woolly mammoth and other...