While humans and other mammals exhibit little or no ability to regenerate damaged limbs, tissues, and organs, many more primitive animals--including marine species such as skates and sharks--can do so. Indeed, animals representing all major groups of limbed vertebrates can grow new limbs as adults, suggesting that regeneration was once the norm for vertebrates.
At what point in evolution was the ability to regenerate complex tissues, organs, and limbs lost? Can regenerative capacity be restored in mammals? Scientists in the Davis Center for Regenerative and Aging Biology are defining the cellular and molecular mechanisms of regeneration in a variety of non-mammalian organisms to understand what underlies the process of regeneration and, potentially, to point the way to new therapies.