The Crab at the Shore of the Known Universe

Meet today’s weird critter, the Yeti Crab!

It was only discovered in 2005, so scientists haven’t had time to study them properly yet. But they do know that those filaments on the arms house a bacteria which the crabs probably eat, and which might also filter out toxic chemicals from the water around the deep-sea vents where the crab lives.

And it’s those deep-sea vents I want to focus on. You see, all life on Earth relies on photosynthesis, in which plants use the sun’s radioactivity to turn minerals into sugars and starches. Even the hagfish and sea cucumbers that live in the pitch black sub-basement of the ocean and have no concept of what a “sun” is rely on the decaying material that falls from the sunlit realm above. To reiterate, all life on Earth ultimately relies on the sun. All life, EXCEPT, that is, life around certain rare deep-sea vents that spew sulfurous gases. There, a bizarre new ecosystem, divorced from every other earthly thing, relies not on photosynthesis but on chemosynthesis, an entirely different pathway by which bacteria turn sulfur into sugars and starches. These animals draw their energy not from the sun, but from the earth itself. The yeti crab is one of these.

You can see how the discovery of hydrothermal vent ecosystems was a total shock: here were life forms that played by an entirely different set of rules than every other life form. When presented with a vacuum that could be filled, it seems, life will find a way to fill it. And this may not just apply to the remote parts of Earth with different laws of biology,

but alternate universes with entirely different laws of physics.

If you want to know what “quantum biology” is about, check this out: The January issue of Scientific American leads with a study on the potential for life elsewhere in the multiverse. You may know the multiverse from such popular science fiction as the totally awesome Sliders, in which fucking Jerry O’Connell goes zipping around in parallel Earths, which are usually pretty much the same as this one except everyone there is, say, a vampire, or speaks Pig Latin. The root of the multiverse theory is that our universe, instead being Big Banged, was born from an infinitesimally small vacuum that, most likely, birthed other universes besides ours. It’s possible that these universes are infinite, and in another universe, another you is reading this very post, except you are a very evolved armadillo. But chances are, most of the other universes have totally different laws of physics.

It wouldn’t take much. A tiny difference in the weight of quarks (those subatomic particles that make up protons and neutrons) could mean that matter as we know it wouldn’t exist at all in those worlds. It’s generally thought that life is pretty rare; we haven’t found it anywhere but Earth, and it probably wouldn’t exist in a universe in which, say, carbon failed to materialize, or friction wasn’t sticky. But a couple of physicists did some models, and discovered that, even with a different set of physics in which the helium that fuels our sun doesn’t exist, stars could still be born, and a different isotope of carbon, and thus life could exist.

I’m inclined to believe them. If the yeti crab and its ilk have anything to teach us, it’s that we’re only living by one set of rules, and we shouldn’t imagine it’s the only game in town. Hell, maybe in another dimension, in which a weak sun fuses hydrogen and deuterium to create cold light, a giant crab is typing this with arms even hairier than mine.

Next Post: Imagining an alternate prehistory of Antarctica!