The best science fiction and fantasy is rooted in reality. Arthur C. Clarke’s classic 2001: A Space Odyssey showed what could happen if our current computers developed human-like intelligence and emotion. Michael Crichton’s Jurassic Park captured the imaginations of kids and the young-at-heart with a seemingly plausible parable on how to resurrect long-extinct dinosaurs (look for a post on this possibility in the future). And as in Marvel’s Fantastic Four comics, the universe’s planets are often threatened with consumption by a peckish giant in a purple skirt.
Okay, maybe scratch that last one, but what about some of the superhuman feats of our more grounded champions? Comic characters get beat up a lot, yet they always seem to come back for more merely a month later. While a healthy suspension of disbelief is required to account for most of that, some of our favorites have built-in mechanisms to explain their near-miraculous recoveries. How realistic are these regenerative capabilities? Might they even translate to human applications?
The world famous Wolverine, star of the breakthrough X-Men movies as well as his own solo venture (with a sequel on the way), is the king of stitching himself back together. His mutant healing factor rapidly regrows enormous amounts of tissue, at one point in his serial even regenerating an entire body around his metallic skeleton after the explosive villain Nitro seared away his flesh. After his amazing ability was supercharged, he was even able to bring himself back from a single drop of blood!
Such stunts will never be within our grasp, but the concept itself is not unheard of. Planarians, commonly called “flatworms,” are simple critters less than an inch long that typically live in ponds and rivers. They themselves are famous for coming back from extreme situations, spawning multiple complete organisms when cut into pieces. In one mind-blowing study, a planarian was irradiated so that none of its cells could reproduce and it would slowly die. A single, solitary c-Neoblast (an undifferentiated unit akin to stem cells) was transplanted from a donor into the victim’s tail, and subsequently grew all the former tissues back to create a new, functional animal! Too bad people are not planarians.
Sure, coming back from a single cell or a little bit of blood is literally incredible. How about something simpler? Like, I don’t know, decapitation? Wolverine’s final foe in the X-Men:Origins film was the regeneratin’ degenerate known as Deadpool, a product of the same super secret government program and perhaps the only dude bad enough to rival our hero in the healing department. The creep’s head was shown to still be conscious after being removed from his body, a fate the comic book counterpart has suffered on numerous occasions, proving it to be little more than a minor inconvenience.
The many-headed, mythologic Hydra would regrow two heads for every one lopped off, and the tiny creature for which it’s named is not far behind. Composed of a basal disc used to adhere, a tubular body and a mouth opening surrounded by thin tentacles, the bitty beast will actually regrow its “head” when lost, thanks to constant mitosis (cell reproduction) in the body. If a hydra is chopped up in a blender (who came up with that experiment?), a centrifuge can be used to reaggregate it and bring it back to life, much like Deadpool returned from being smashed to bits by the sinister Iceman in “Uncanny X-Force #16″. I wouldn’t try this one at home.
All right, all right, no one’s expecting that we’ll ever be able to regrow a head or our entire musculature, but something like limb regeneration seems just feasible enough. So much so that Dr. Curt Connors, an ordinary scientist, tried to restore his departed right arm with a serum inspired by reptilian recuperative tactics. The treatment succeeded, but side effects included skin irritation, spontaneous tail appearance and a beatdown from the Amazing Spider-Man.
Similar to a scene in the cinematic adaptation of 2012, there are lizards called skinks whose tails snap off when grabbed by predators, allowing the animal to escape. Amphibians are better known for regrowing limbs, but the potential for human use recently took a less optimistic turn. It has long been thought that such recuperation was a skill developed early in evolution, and that the ability had been “switched off” in mammals and birds. New studies of the red-spotted newt, however, show that many of the newt’s RNA transcripts that code for proteins used in the process are unique to the organism, i.e. not found in other things like us. That innate ability may just not be there for people, and no magic potion is likely to instill it.
WHAT DOES THIS MEAN?
You should take any story of human regeneration with a grain of salt. In 2008, hobby store owner Lee Spievack claimed to regrow a lost fingertip by applying a powder derived from pig bladders, an assertion called “junk science” by University of Leeds professor Simon Kay, adding that, “If you could regenerate body parts like this, your first port of call would be a serious science journal like Nature because it would be a Nobel prize winning revolution.” A similar if not as spectacular story was reported by Californian Deepa Kulkarni, but closer examination suggests it was the proper dressing of the wound to prevent the growth of scar tissue that restored the finger’s appearance, and not a sprinkling of “pixie dust.”
But perhaps the cause is not completely lost. African spiny mice were found in 2012 to have brittle skin that tears off when attacked; skin they can regenerate complete with hair follicles and sweat glands. The regrowth begins from a clump of cells comparable to the blastemas employed by salamanders. People aren’t mice, either, but at least mice are closer cousins than a minuscule, glorified gut tube. The precedent is now there in mammal physiology, so that one day we may learn how to become superhuman. Ya know, like a lizard.