Regeneration is a popular superpower in comics - after all, who doesn't like the idea of being able to recover from any injury? Let's have a look at nature's take on Deadpool and Wolverine, including...
- Skin-shedding African spiny mice
- Bisectable sea spiders
- Limb-regenerating axolotls
- Head-removing sea slugs
- Hydra that survive being torn apart
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| Some sea slugs can shed their body and regrow from their head! (Christian58) |
1. Skin-Shedding, Spine-Mending African Spiny Mice
Mammals are pretty poor at regenerating injuries - we don't regrow limbs, and we tend to "mend and make do" when it comes to injured organs. There are exceptions to this, however, such as African spiny mice.
These little rodents seem capable of regenerating critical injuries to the heart, spine, kidneys and skin. It was the ability to regenerate skin that first clued researchers into this talent - the mice shed strips of their skin if gripped, allowing the rodent to streak to safety!
Further research revealed that the mice could recover from a severed spine without any problems, going from lower body paralysis to full mobility in a matter of weeks. Other injuries (such as missing skin or holes in the ear) seal and are regenerated in a few days, leaving no scar tissue. Scientists are currently looking into the species in the hope of finding ways for humans to borrow this talent!
2. Bisectable Sea Spiders
One of the less well-known marine creatures, sea spiders, are not true spiders. Instead, they belong to the chelicerates, a group of arthropods containing arachnids and horseshoe crabs - though some researchers suggest that they may be the survivors of an ancient sister group of all other living arthropods.
Sea spiders are not venomous, but they do have an impressive healing factor. Many molting animals (such as lobsters) are capable of regenerating lost limbs when they change shells. Sea spiders take things much further - one study found that juvenile Pycnogonum litorale sea spiders can regenerate their hindbody after being cut in half. This involved growing back segments of the body, anus and gut!
3. Limb-Regenerating Axolotls
Researchers believe that all animals possess regenerative capabilities as an embryo - even humans. This ability degrades or is lost as we develop, but some species of animal retain it through their lives. The Mexican Axolotl is one such creature.
Living as long as 25 years, this salamander retains many of its larval traits into adulthood - including regeneration. They are able to regrow lost limbs and seem resistant to the age-related illnesses and cancers experienced by humans. Regeneration does take more time in older animals, though this may be due to their size - axolotls continue to grow all the way through their lives.
When a salamander loses a limb, cells beneath the wound de-differentiate. Bone, cartilage, muscle and nerves revert to stem cells (like those found in an embryo), which can then grow back into a replacement limb. It's actually possible to grow additional limbs on an axolotl by grafting on tissue that has started to regenerate!
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| The axolotl can regenerate limbs if it needs to... (LaDameBucolique) |
4. Head-Removing Sea Slugs
Some animals can shed and regrow a tail to escape a predator, but there are sea slugs that take things to a whole new level. Scientists have discovered two species that can detach and regrow their entire bodies.
The heads of these sea slugs seem to survive thanks to photosynthesis, using chloroplasts borrowed from algae in their diets. This allows them to function despite having lost most of their organs, surviving on sunlight until replacements can be grown. The old body doesn't just die either - it continues to operate all by itself, sometimes surviving for months without a head.
The exact reasons for this extreme makeover are unknown, but researchers speculate that it could be a way of escaping parasites infesting the body.
5. Sliced, Diced and Thriving Hydra
Perhaps the most impressive example of regeneration is that of the aptly named hydra, a cnidarian that resembles a tiny sea anemone. Not content with replacing limbs, these animals can regenerate from immense physical trauma. If you slice one into pieces, you can expect a "new" hydra to grow out of every portion of the body except the tentacles and "foot." Even if torn into individual cells, hydra can clump back together and regenerate.
The hydra gets these capabilities thanks to being filled with stem cells. When damaged, these cells can rapidly replace missing body parts as needed. This extends well beyond simple healing - hydra are thought to be biologically immortal, as they don't seem to die (or even suffer impairment) from age. In perfect conditions, there's no reason hydra couldn't live forever!
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