Sunday, April 26, 2015
Sunday Science Blog
So you think you're smarter than an octopus?
Octopus dexterity is a thing of awe. One veterinarian saw an octopus undo its own surgical sutures. Divers off the Pacific Northwest Coast have seen male octopuses stand on undersea rocks in the cold salt water, stretching two arms out before them like antennae, apparently searching for that perfect female. Cephalopods – squid, octopus, cuttlefish and nautiluses – have been around for millions of years. The word "cephalopod" means "head-foot."
Some scientists believe that we humans separated from cephalopods, evolutionarily speaking, perhaps more than 700 million years ago. That’s hundreds of millions of years before the Cambrian Explosion, when so many life forms radiated throughout our planet’s oceans. Given that long divergence, we should be very different species. And we are. In some ways.
Cephalopods are invertebrates, animals without skeletons. They usually have eight arms, some have a couple tentacles too. These appendages attach not to the main body; instead, they encircle the animal’s mouth like some kind of living beard. Many cephalopods can change the color of their skin almost instantaneously. Some, like the fabulous cuttlefish, look like flashing neon lights. These guys are weird.
And yet – they are a lot like us, in some very basic ways. For one thing, we both have similar brain cells. For almost 100 years, scientists have used the giant axon of a little squid, Loligo pealeii, to study how our own brains work.
In most animals, the neuron is the cell that’s the central processor of the world outside the body. The neuron has a main body and an axon, a long thin living tube that extends from the main body somewhat like a thread or a wire. Our own axons are gossamer-like, delicate and easily damaged. It’s difficult for researchers to work with them. But the little squid’s axons may be as thick as a pencil lead. They are visible to the naked eye and are easily handled.
By studying how the squid axon works, scientists have learned quite a bit about how ours function. They hope to apply some of what they’ve learned to finding cures for diseases like Alzheimer’s.
Disturbing Octopus Facts and Their Eventual Global Conquest
Planet of the Apes?
It’s an OCTOPUS UPRISING we need to worry about:
Intelligent eight-tentacled animals could evolve to become even smarter Octopuses are highly intelligent, more so than any other invertebrates
They can be trained to distinguish between different shapes and patterns In some studies, they have been shown to practice observational learning
Scientists says they may one day build structures other than simple shelters
MEASURING THE MINDS OF OTHER creatures is a perplexing problem.
One yardstick scientists use is brain size, since humans have big brains. But size doesn’t always match smarts. As is well known in electronics, anything can be miniaturized.
Small brain size was the evidence once used to argue that birds were stupid — before some birds were proven intelligent enough to compose music, invent dance steps, ask questions, and do math. Octopuses have the largest brains of any invertebrate. Athena’s is the size of a walnut — as big as the brain of the famous African gray parrot, Alex, who learned to use more than one hundred spoken words meaningfully. That’s proportionally bigger than the brains of most of the largest dinosaurs. Another measure of intelligence: you can count neurons.
The common octopus has about 130 million of them in its brain. A human has 100 billion. But this is where things get weird. Three-fifths of an octopus’s neurons are not in the brain; they’re in its arms. “It is as if each arm has a mind of its own,” says Peter Godfrey-Smith, a diver, professor of philosophy at the Graduate Center of the City University of New York, and an admirer of octopuses.
For example, researchers who cut off an octopus’s arm (which the octopus can regrow) discovered that not only does the arm crawl away on its own, but if the arm meets a food item, it seizes it — and tries to pass it to where the mouth would be if the arm were still connected to its body. “Meeting an octopus,” writes Godfrey-Smith, “is like meeting an intelligent alien.”
Their intelligence sometimes even involves changing colors and shapes. One video online shows a mimic octopus alternately morphing into a flatfish, several sea snakes, and a lionfish by changing color, altering the texture of its skin, and shifting the position of its body. Another video shows an octopus materializing from a clump of algae. Its skin exactly matches the algae from which it seems to bloom — until it swims away.