Warning: Mutant chickens may bite. Researchers have identified a genetic mutation that creates incipient teeth in bird embryos. The discovery provides a modern day glimpse of a feature that hasn't been seen in avians for millions of years.
Birds lost their choppers 70 million to 80 million years ago. That's what made an experiment in 1980 so surprising: After scientists grafted oral tissue from mice onto a chicken's gums, the birds grew round, mouselike teeth. But because avians and mammals are not closely related, scientists doubted whether the experiment proved that birds had truly retained a genetic vestige of their forbearers' bite.
