From NPR.

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 extinct species.

Scientists implanted genetically modified embryos in female lab mice that gave birth to the first of the woolly pups in October.

"This is really validation that what we have in mind for our longer-term de-extinction project is really going to work," Shapiro told NPR in an interview. The company says reviving extinct species like the mammoth, the dodo and others could help repair ecosystems. Critics, however, question whether de-extinction would be safe for the animals or environment.