crossposted from unbossed
Well, SSF is back from winter vacation, tan, rested, getting over a cold from all that glad-handing and air travel, and ready for some lifely talk about intelligent life.
And at long last about octopuses. To get started, here is a link to a video of an octopus escaping from a plexiglas box. Video copyright James B. Wood 2006 Notice how the octopus elongates its head into a 1 inch cylinder that stretches back far from the hole - it seems to have measured the hole's diameter and anticipated exactly how small its head must get to go through. It doesn't just squish its head through.
If a conversation with a bottlenose dolphin would give us some interesting perspectives, remember that we and dolphins are both mammals and therefore have a lot in common. Our ancestors were hanging out together a relative blink ago compared with, say, an octopus. Consider a heart-to-heart conversation with a creature whose ancestors diverged from ours about 1.2 billion years ago. "Genetic studies show that mollusk ancestors split from the vertebrates around 1.2 billion years ago, making humans at least as closely related to shrimps, starfish, and earthworms as to octopuses." link
So different are octopuses from us - not only in living in the oceans but in structure and apparently motivation - that it is difficult to know what scale to use. It is unlikely that we will be having tea and discussion together any time soon, but here are some interesting bits of evidence as to octopus intelligence. Or perhaps that evidence has been misinterpreted.
More study is certainly needed, but it is fun seeing where we are now and speculating about possibilities.
Until recently, we thought that, technically speaking, octopuses and humans saw the world in the same way because we both have "camera eyes" but that this was merely a coincidence - a consequence of convergent evolution and not evidence of any true similarity between us. However, new research shows that we and they have a lot in common - at least when it comes to how we see. Although perhaps not in how we see things, if you get my pun.
We know that at the gross anatomical level the brains of mammals and octopuses are very different. Octopuses store some of their brain power in their arms. Here is another link showing anatomy and pictures.
There is evidence of octopus intelligence, but that evidence, though interesting, is not without controversy. link
Some captive octopuses lie in ambush and spit in their keepers' faces. Others dismantle pumps and block drains, causing costly floods, or flex their arms in order to pop locked lids. Some have been caught sneaking from their tanks at night into other exhibits, gobbling up fish, then sneaking back to their tanks, damp trails along walls and floors giving them away.
That Steve was named Steve was also revealing: Octopuses are the only animals, other than mammals like cuddly seals, that aquarium workers bother to name. So Anderson, Seattle's lead invertebrate biologist, began to wonder: If keepers recognize octopuses as individuals, how much difference is there among individual octopuses? Might these bizarre-looking mollusks have personalities? And if so, how else might their evolution have converged with ours across a billion-year chasm?
Meanwhile, in the waters off Bermuda, Canadian comparative psychologist Jennifer Mather was asking similar questions. Mather had observed an Octopus vulgaris, the common Atlantic octopus, catch several crabs and return to its rock den to eat them. Afterward it emerged, gathered four stones, propped these at the den entrance and, thus shielded, took a safe siesta. The strategy suggested qualities that weren't supposed to occur in the lower orders: foresight, planning, perhaps even tool use.
This article discusses some of those differences and reviews some research on octopus intelligence, including this:
The US Air Force thought that studying octopus might help their engineers design better computers. But the octopus proved far too complex for them.
Fifty years later the cephalopod's brain remains a mystery. Cephalopods are not much like us in their body plans or their lives. Many are underwater predators and are powered by high-speed jet- propulsion systems. Those that live socially communicate with each other using patterns of body colour which change so rapidly that they make our own facial expressions look sluggish.
They also have very differently organised nervous systems. They have large brains but in order to react very rapidly and control the movement of many rubbery legs (as well as controlling their body colour), a lot of information processing happens in ganglia distributed around the body. What mental powers do they have?
Recently there has been a new ripple of interest in their psychology after researchers at Naples found evidence that one octopus was capable of learning by watching what another octopus did. "Observational learning" was thought to be evidence of intelligence and restricted to the "higher" mammals and birds.
The experiment has not yet been repeated, but there is a sense in which it may miss the point. Until the 1970s, researchers tried to classify the intellectual abilities of different animals and rank them within a universal intelligence scale with humans at the top. That view crumbled as it became obvious that the abilities of different animals were tuned to the circumstances in which they live. link
One of the issues discussed in that piece is evidence that octopuses can learn tasks from observation of other octopuses. What is most interesting is more possible evidence of intelligence. It is that one operating theory is that intelligence develops among social animals, and one important part of intelligence is learning by observing others in the flock / herd / group. So far we have found intelligence among social animals - humans and other primates, crows and other birds that flock, and elephants all can learn from observing others.
But we observe that octopuses live solitary lives for the most part. It's hard to understand why a non-social animal would develop this capacity. Yet we have evidence that at least some octopuses have learned by observation.
In fact, you may have seen this BBC story of an octopus that learned to open jars by watching humans. And here is the story of another such octopus.
Perhaps octopuses survive by being keen observors of prey and enemies. And as for being solitary, perhaps that conclusion is based on our inability to observe. There is some evidence that octopuses communicate with others across distances. link:
Other evidence suggests that solitary octopuses, like solitary orangutans, may communicate more with others of their species than researchers previously realized. Cigliano found that California octopuses that were kept together quickly established hierarchies and avoided wasteful, dangerous confrontations; the weaker animals seemed to recognize and yield to the stronger ones, even when the latter were hidden in their dens. The flip side of communication is deception, another hallmark of intelligence. And some octopuses and cuttlefish practice it. Male cuttlefish adopt female coloring, patterns, and shape—to mate surreptitiously with females guarded by larger rivals. And the Indonesian mimic octopus fools predators by impersonating poisonous soles and venomous lionfish, sea snakes, and possibly jellyfish and sea anemones.
More ceph links
here is a link to videos, articles, and more on cephalopods (octopus, squid, cuttlefish and nautilus).
You can find here a summary of octopus intelligence, including:
- "Reference memory for places where food might be found and working memory for where they had already hunted."
- Spatial memory
- Tool use
One way octopuses use water as a tool is to change the niches that they find in the landscape to make them into suitable shelter, into homes. An octopus will find a 'likely' place, but it is usually clogged with sand and the shape may not be appropriate. It will gather sand and small rocks into the area under the arm web and carry them out to the entrance of the home. Once there, it will tilt up the web, let go with the suckers and jet it all away with a blast of water from the siphon. For a smaller amount of material it may not carry but just jet water at it, much as we would sweep with a broom.
A second way octopuses use water as a tool is to get rid of what could be described as nuisances. After capturing crab prey, the octopus will usually kill them and hold one or several under the arm web, dissolve the cartilage holding the joints together, digest out the meat, and keep the exoskeleton bits. When it's finished, it will take the remains to the den entrance and jet the lot out into what becomes a midden. If a scavenging Serranid fish comes by to eat these remains, the octopus may jet a blast of water to remove the 'pest' from the vicinity (Mather, 1992, Marine Behaviour and Physiology 19, 175-182). This water jet can be aimed also at a curious observer or researcher, as has happened to both of us when removing bits of prey remains to catalogue them, or just getting a hand too close to the octopus.
What all this means is that the octopus has a lot of flexibility in using the water all around it to change its environment, that it can compute the effect of what is really a current for respiration and use it in a lot of ways. We discovered that this water jet could be used in a behaviour that's really far from what is expected of an invertebrate. Octopuses can use the water jet to play, too.
Play, tools, and Learning
Octopuses seem to play with toys and their environment and may do things that demonstrate a sense of humor. link
Previous researchers tested octopuses in artificial mazes; Mather and Anderson found ways to observe learning and cognition in more natural circumstances. They charted the efficiency and flexibility with which giant Pacific octopuses switch strategies to open different shellfish—smashing thin mussels, prying open clams, drilling tougher-shelled clams with their rasplike radulae. When served clams sealed with steel wire, for example, octopuses deftly switched from prying to drilling.
Tool use was once commonly invoked as uniquely human. Scientists know better now, but they still cite it as evidence of distinguishing intelligence in chimpanzees, elephants, and crows. Mather describes several ways octopuses use their water jets as tools: to clean their dens, push away rocks and other debris, and drive off pesky scavenger fish.
In 1999 she and Anderson published an even more sensational claim: that octopuses engage in play, the deliberate, repeated, outwardly useless activity through which smarter animals explore their world and refine their skills. Amateur aquarists were the first to suspect that octopuses played. While still in high school, James Wood, now a marine biologist at the University of Texas's marine lab in Galveston, watched his pet octopus grab, submerge, and release her tank's floating hydrometer as if she were a toddler with a bath toy. She also spread her mantle and "bubble surfed" the tank's aerator jets.
Anderson tested for play by presenting eight giant Pacific octopuses with floating pill bottles in varying colors and textures twice a day for five days. Six octopuses examined the bottles and lost interest, but two blew them repeatedly into their tanks' jets. One propelled a bottle at an angle so it circled the tank; the other shot it so it rebounded quickly—and on three occasions shot it back at least 20 times, as if it were bouncing a ball.
For teachers, here are some cephalopod lesson plans
For octopus fanatics, here is your site - The Octopus News Magazine.
For earlier parts of this series on intelligence, see:
Sunday Science Fun - Intelligent Life, Part 1