How Do Axolotls Work?

of similarity between axelattles and human beings. In considering these feathery, pinkish salamanders, he says, it would seem easy, almost obvious, to fall into mythology. Cortisaar's narrator is, on the face of things correct in his estimation of the Axelatal for starters, the Oxelotal fell into mythology centuries ago. According to Aztec legends, the first Oxelotal appeared in the Lake system around modern day Mexico City, when the powerful underworld god Zolat transformed

himself into a small, feathery amphibian to escape capture. In ancient Mesoamerican culture, oxelotals were considered a food source supplied by Lakes of Jamilico for the good of humanity, and Courtsar was right about the oxelotals lack of similarity to humans, Our last common ancestor probably roamed earth around three hundred and sixty million years ago, and at first or even

fiftieth glance, they're excessively different from us. Among the first modern zoo animals, thirty four oxelotals were brought from Mexico to Paris in eighteen sixty four, and although they weren't as interesting to nineteenth century zoo goers as the larger, more charismatic animals, scientists quickly realized that these unassuming little buddies were strange, almost mythological in fact, in the wild, oxel attles are or at least used to be top

predators in their home ecosystem in the lakes and canals of central Mexico. They're unusual among amphibians because they remain underwater for their entire lives, breathing through gills, while most other salamanders walk around on land and breathe with lungs

during the adult stage of their life. Although they appear on assuming they're actually ruthless carnivores feasting on worms, mollusks, insects, and even small fish in the wild, and it turns out that they have the largest genome of any organism yet sequenced. Part of the Aztec mythology of the oxelotal centers around the fact that, like a powerful god, they're difficult to kill, and that they can regenerate virtually any

part of their body without much problem. While some lizards can grow back a tail bisected, flatworms can grow back their other half, and starfish can regrow a limb, an oxelotal can regrow its heart, afoot a part of its spinal core, you name it. We spoke with David Gardner, professor in the School of Biological Sciences at the University

of California, Irvine. He said, of the animals that are closest to us, the vertebrates, salamanders are the only ones that can regenerate in this way and can heal without scars. Other salamanders can regenerate, but oxelotles do it best. When the Europeans got wind of this, oxelotles went from being a sort of boring exhibit in the zoo to one of the most important and the longest self sustaining lab

animals in history. George Couvey, popularly considered the father of paleontology, studied axelottles in an attempt to figure out whether Carl Linneus was correct in categorizing the classes Amphibia and reptilia separately. It was a big question in those days. Covie incorrectly concluded the oxelotles, because they breathe through gills their entire lives, must be some sort of lizard that existed as a perpetual law va, in the words of paleontologists Stephen Jay

Gold quote a sexually mature tadpole. Couvy was correct sometimes, but not in this case. And because oxeltles did incredibly well in laboratory and aquarium settings, a nineteenth century zoologist took it upon himself to provide every lab in Europe with a supply of them, which resulted in some truly horrific studies in which scientists chopped them up just to

test the limits of their regenerative powers. Gardner said, these days, oxyletles are hugely important model systems for our studies about regeneration. We've known for decades, centuries even that we can remove parts of a developing embryonic structure and the cells that are left behind will fill in, repair, and regenerate that structure. But in most animals and mammals, for instance, the system sort of shuts down at the end of embryonic development.

Salamanders seem to be able to revert back to that embryonic like state, re accessing the developmental program that's already there. Humans have the program, we just stop being able to access it when we're no longer an embryo. You could say, we, like oxylottles, have evolved the ability to regenerate just fine, but we've also evolved a mechanism that inhibits that. Oxeltles can endure a lot, but they have not been able to endure their home ecosystem, being overrun with introduced predators

and environmental toxins. The lakes in their home around ultra urbanized Mexico City have become not only polluted by aging wastewater systems, but overrun by introduced telapia and perch, both of which view oxylottles as a delicious snack. Scientists counted around six thousand oxeltals per square kilometer in Lake Zotomilco, but these days fewer than thirty five animals take up

the same amount of space. It looks like the oxylottle is on the fast track to extinction even in their home environment, which is something of a paradox like the oxelottle itself. While wild oxelttles are critically endangered, they're doing great in captivity. They're the most widely distributed amphibian in the world. Millions of them live in labs around the globe, many more in fact, than live in the wild now, and while they're important in science, they're also quite popular

in pet shops. Today's episode was written by Jesslin Shields and produced by Tyler Clang. For more on this and lots of other regenerative topics, visit how stuff works dot com. Brain Stuff is production of iHeart Radio or more podcasts. My Heart Radio visit the iHeart Radio app, Apple Podcasts, or wherever you listen to your favorite shows.