For humans, regrowing a lost body part would require superpowers. But for some other animals, it’s business as usual.
Salamanders are perhaps the most famous examples. If a salamander loses a leg or a tail, it can grow a new one in a matter of weeks. Golden apple snails can rebuild eyes within months. Some sea spiders can regrow their backsides in months, too. And those aren’t even the most extreme cases of regeneration. Some sea slugs can rebuild their whole bodies from the head down!
Scientists have long been fascinated by animals’ powers of regeneration. They want to know why some creatures can rebuild body parts while others can’t — and how these species pull off their feats of superhealing.
Recent studies have offered some clues. Salamanders, for instance, develop very slowly. As a result, adult salamanders may still have plenty of stem cells in their bodies. Stem cells can grow into many different types of tissue, making them useful building blocks for new limbs. Lungfish — which also develop slowly and can regenerate — may have a similar trick in their genes as salamanders.
Scientists have also watched closely as salamanders and fish regrow limbs and fins. Researchers have found that in these species, immune system cells, blood cells and repair genes work together to help new tissue grow at a wound site.
Such insights might someday bring the power of regeneration to people. Experiments in frogs have already suggested this may be possible. Scientists worked with African clawed frogs that had lost a limb. Those frogs don’t normally regenerate. The researchers built a device that held a special mix of medicine at the wound sites. Over 18 months, the medicine coaxed their bodies to grow new limbs.
Just because this treatment worked on frogs doesn’t mean it would work on people. But the results do hint that just maybe, future technology could make comic-book superhealing a reality.
Want to know more? We’ve got some stories to get you started:
A new drug mix helps frogs regrow amputated legs Coaxing animals to regrow limbs could be a stepping stone to giving people the same ability. (2/25/2022) Readability: 6.6
A sea slug’s head can crawl around and grow a whole new body Some may disconnect a parasite-infested body, then grow a new clean one. (4/30/2021) Readability: 6.7
Living mysteries: This critter has 38 times more DNA than you do DNA may offer clues to how salamanders and lungfish are able to regrow body parts. (9/29/2022) Readability: 6.8
Explore more
Explainer: What is a stem cell?
Explainer: What is the immune system?
Regeneration of fins and limbs relies on a shared cellular playbook (from Science News)
This snail may hold a secret to human eye regeneration (from Science News)
Some young sea spiders can regrow their rear ends (from Science News)
How salamanders can regrow nearly complete tails but lizards can’t (from Science News)
Gene-edited stem cells help geckos regrow more perfect tails (from Science News)
Activities
Animals aren’t the only ones that can regrow lost pieces of themselves. Plants can do it too — though some are better than others. Learn which plants best regenerate after damage in this experiment from Science Buddies.
