Biologists long have been fascinated by the ability of salamanders to regrow entire limbs. Now Harvard researchers have solved part of the mystery of how they accomplish this feat — by activating stem cells throughout the body, not just at the…

Biologists long have been fascinated by the ability of salamanders to regrow entire limbs. Now Harvard researchers have solved part of the mystery of how they accomplish this feat — by activating stem cells throughout the body, not just at the…