Mammals Could Once Regrow Limbs

Salamanders are unique among their four-legged vertebrate brethren in that they can regenerate tails, limbs and even internal organs throughout their lifespan.

Salamanders, in short, can heal themselves.

Could studying the salamander’s spectacular regenerative ability translate into advancements in animal and human medicine? Researchers have long hoped so — and now new findings add key information.

Recent fossil discoveries from the Carboniferous and Permian periods — around 300 million years ago — show that some other amphibian groups may have regenerated legs and tails in a way similar to salamanders, suggesting that all land mammals once carried within them the ability to regenerate limbs.

That ability was lost through time.

“The fossil record shows that the form of limb development of modern salamanders and the high regenerative capacities are not something salamander-specific, but instead were much more widespread and may even represent the primitive condition for all four-legged vertebrates” lead author Nadia Fröbisch said in a release.

“The high regenerative capacities were lost in the evolutionary history of the different tetrapod lineages, at least once, but likely multiple times independently, among them also the lineage leading to mammals.”

Read more at Discovery News