Category Archives: Amphibians

Land of the Lost

The other day we discussed adaptive radiation, the process by which a single ancestor can split into an aardvark, an elephant, a manatee and a mole. But how do species split from one another? Usually by being physically separated for a good amount of time. The obvious illustration would be a species radiating between islands, but “islands” can occur on land, too. Even within islands.


Rodents Of Unusual Size? I don’t think they… oh, there’s one.

Meet the Bosavi Woolly Rat, a cuddly cat-sized rodent and the largest rat in the world. What makes it remarkable isn’t just its size, but its location. It was discovered only last year in the Bosavi volcanic crater in Papua New Guinea, along with at least 40 other amazing animal species heretofore unknown to science and native only to this one crater, including a fanged frog, a fish that “grunts,” a marsupial called the Bosavi silky cuscus, a tree kangaroo, a new family of sleestaks, an ogre-faced spider that fishes for its prey, a new species of bat, the world’s smallest parrot, a new bird-of-paradise and caterpillars that collaborate to look like a snake. These creatures had no fear of humans, having probably never seen one before. After all, they’ve been walled inside an extinct volcano for 200,000 years.

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Oblivious

Yesterday I talked about the animal that gets the most sunlight. Today, one that gets none at all.

It’s the Olm, also called the Proteus. It’s an amphibian endemic to the subterranean caves of the Balkans, and being cave-dwelling, it has no use for eyes or pigmentation. Its body has become serpentine, to incorporate more touch receptors. Its tiny feet, instead of having the four toes like most amphibians, have only three toes each on the front limbs, two on the hind. Like the axolotl, it retains neotenic features such as external gills: it is a dragon embryo surviving in the dark, an infantile troglodyte.

With its acute sense of smell and touch, the olm gets along just fine in what, for us, would be the equivalent of a sensory-deprivation chamber. Hundreds of yards beneath the Earth’s surface, the water temperature remains constant, there is almost no sound, and the olm has no predators to worry about. But then, there is very little food. Barring tiny crustaceans and snails, as well as its own bacteria-laden skin molts, there is almost nothing to eat in a world so far removed from the sun. Instead of shutting down its life functions like the water bear, the olm has gained the ability to go up to ten years without eating. With a lifespan of up to 70 years, and perhaps even 100, an unlucky olm may eat only a few times in the course of a century. But centuries do not exist here: where the olm lives, there are neither years, nor seasons, nor hours, nor day and night.

If outer space is a vacuum, there are places in inner space that are as close to oblivion as possible, and there is a vertebrate uniquely adapted to thrive here in this near-nothingness beyond light and time – slithering, starving, waiting for rains it will never know to wash down a few crumbs of life to eat. As an atheist, I think of Earth as the closest thing to Heaven. But there is also an underworld here, like the atheist’s afterlife: noiseless, blank, without time or change or meaning. And here, too, life persists.


Airbenders

The origins of flight are debated, but one thing is certain: it began as gliding. And, most likely, it began as gliding from tree to tree in the forest canopy. As of yet, there are only two ways to truly fly: have wings on the back (like insects), or wings on the forelimbs (like birds and bats). But nature is constantly innovating, finding new ways to get high. Today, we look at some gliding prototypes being developed in the laboratory of the rainforest canopy, and imagining what kind of flying animals they might become.

The Prototype: Flying Dragon

I love animals that sound like kung fu moves. The flying dragon of Southeast Asia has developed a different way to glide: it extends flaps of skin connected to special, movable ribs to create “wings” in its midsection; its obvious advantage is that, unlike birds or flying squirrels, its arms and legs are free, so it can read the SkyMall catalogue. It’s able to glide about 25 feet, even executing a nifty little loop-de-loop to slow its descent near landing.

The Future Model: The Butterfly Lizard

Okay, gliding lizards have existed for 144 million years. So if this design could turn into powered flight, it probably would have by now. But if you gave the lizard a keel, the breastbone in birds to which the flight muscles attach, the flying dragon could conceivably evolve into a fluttering lizard with brightly-colored wings, making short, powered jumps upwards into the canopy to catch slow-moving insects in its elongated forearms.

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Axolotl

Meet the axolotl. It’s a type of aquatic salamander, endemic only to the nearly-extinct Lake Chalco underneath Mexico City, and the nearly-extinct Lake Xochimilco. As you can imagine, it is nearly extinct in the wild. The species is mainly bred as pets, for scientific experiments, and for food. (It was a staple of the Aztecs, and remains so today, fried by street vendors.)


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