"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." A 2021 study out of Japan showed how targeting genes can regrow teeth in animals. Now, the team has ...

Piranha teeth have the tough task of crunching bone and shredding flesh and, like well-used kitchen knives, they dull over time. Since they have no way to sharpen their teeth, piranhas lose and regrow ...