Friday Squid Blogging: Squids Have Personality

At least the Southern Dumpling Squid does:

Squid have personalities that appear to be passed down from parent to offspring, but those traits can be modified by environment, an Australian researcher says.

Posted on April 28, 2006 at 3:47 PM • 12 Comments

Comments

JungsonnApril 29, 2006 1:53 AM

"He says this is probably to compensate for the loss of their protective shells during evolution, with more brain capacity needed to protect their vulnerable bodies from predators."

I don't think brainsize has anything to do with this. A simple "ink" mechanism can instantly protect the squid, you won't need a brain to understand that. If brainsize "mattered" the elephant would be ultra smart.

Bruce SchneierApril 29, 2006 8:07 AM

"I don't think brainsize has anything to do with this. A simple 'ink' mechanism can instantly protect the squid, you won't need a brain to understand that. If brainsize 'mattered' the elephant would be ultra smart."

I think you misnderstand how evolution works. Evolution does not result in the best, most efficient, easiest, or most logical solution to a problem. Evolution does not try different solutions until it settles on some optimal one. Evolution tries random solutions, and stops at the first one it finds that just barely works.

mud and flameApril 29, 2006 7:13 PM

@Jungsonn:
"A simple 'ink' mechanism can instantly protect the squid, you won't need a brain to understand that."

Cephalopods' defense against predation isn't just a matter of "one squirt and you're safe." Some cephs squirt out a blob of ink and mucus that's the same size and shape as they are, while lightening their own colors and jetting away, so that the predator attacks the blob. Others ink and then change to a dark color and a drifting-blob-like shape, so that the predator mistakes them for more ink.

Their defenses are also not limited to inking; they often involve changing color, pattern, and body language in complex ways in order to hide or mislead. In one study, young cuttlefish who saw a predator moved away with erratic motions while alternately changing their colors to match the sand below them and then the floating algae around them. The mimic octopus can change its coloration and body language to impersonate several different kinds of poisonous animals, including a sole, a lionfish, and a sea snake, and it chooses among these based on the natural predators of the animal attacking it. _Sepioteuthis_ squids can show 40 or more different body-color patterns to confuse or deter predators, which is so effective that in hundreds of hours of observation all attacks on them were unsuccessful.

No one is suggesting that cephs brainstormed defensive ideas and thought up all these behaviors on their own; just that they're complex behaviors and require some brains to carry out. It's hard to quantify exactly how smart they are, and the idea that you can compare a cat's and a squid's intelligence by their relative brain weight is pretty silly in my opinion. But they're clearly brainy as hell compared to other mollusks. It makes sense to speculate that the lack of external shells creates a need for all these complicated defensive behaviors that take more brain cells.

Filias CupioApril 30, 2006 5:15 PM

"Evolution does not result in the best, most efficient, easiest, or most logical solution to a problem. Evolution does not try different solutions until it settles on some optimal one. Evolution tries random solutions, and stops at the first one it finds that just barely works."

This is overstating things. Evolution uses a local optimisation algorithm - i.e. it uses hill climbing. It doesn't stop when the solution "just barely works", it stops when it reaches the top of the local hill. It then stays there until environmental changes change the fitness landscape, and either the hill shifts (and evolution follows the shift) or the hill gets submerged (quickly followed by extinction.) (One way for an organism's hill to get submerged is if another organism finds a better hill in the same ecological niche and raises the water level by outcompeting them.)

A different organism has a different start point on the fitness landscape, and so may climb a different hill. Consider fish and dolphins. In terms of shape, they climbed the same hill (shapes are very similar), except for the axis they undulate to move: fish side-to-side, dolphins up and down. In terms of hearing, the dolphins found a better hill, because their start point (air-adapted hearing system) was different.

jayhMay 1, 2006 8:51 AM

>>and the idea that you can compare a cat's and a squid's intelligence by their relative brain weight is pretty silly in my opinion

this is correct. Ceph neurons do not have a myelin sheath hence they cannot be packed as tightly without crosstalk. Nonetheless animals like squids and cuttlefish display some pretty high intelligence relatively speaking from a brain organization very different from vertebrates. In a sense it's natures way of reminding us that there is more than one way to achieve intelligence.

Side point: Unlike vertebrate eyes, which have blood vessels in front of the retina (a dumb idea which reduces performance and requires very fragile vessels), cephs feed the retina the 'right' way, from the back. As I understand it, this is because, while there are superficial similarities in our eyes (required by the laws of optics) the evolution is from entirely different starting points. Vertebrate retinas are actually a part of the brain (and are thus nourished from the outside) whereas cephalopod retinas evolved from skin and are nourished from the back side.

JungsonnMay 1, 2006 10:59 AM

"I think you misnderstand how evolution works. Evolution does not result in the best, most efficient, easiest, or most logical solution to a problem. Evolution does not try different solutions until it settles on some optimal one. Evolution tries random solutions, and stops at the first one it finds that just barely works."

That's open for discussion. i cannot agree that evolution tries "random" solutions, i really do not believe in randomness a such in evolution, because biological seen, it will always adapt at it's own circumstances. The circumstances maybe totally random (in some way) but, it cannot be fully random. It's also more nucanced i think, sometimes nature uses the path of least resistance, and sometimes not. This is easy to understand with chimps, they can survive without us (even better i guess) so humans as results of that evolution line would -not be logical- beacause it would require more effort in evolving into a human. Life itself is organizing itself, but not at the roulette table. Also if life would take the line of least resistance, it would not produces any life at all, there would be only an energy cloud in this universe. So, cannot agree this time.

AnonymousMay 1, 2006 11:06 AM

@mud and flame

You won't need braincells, or a bigger brain to be optimal protected. Much of our own defence lies in our nerve cells in the spine an the autonome nerve centre, which instanly responds to danger. This system does not require a "brain" bacteria do not have brains, and yet they can adapt very rapidly to any circumstance, maybe even better than the "higher evolved life at the topmost foodchain"

RoedyMay 19, 2006 3:09 PM

To have a discussion about brainsize and intelligence, you first need data on brain weights and evidence of intelligent behaviours.

I find humans love to pontificate on the lack of intelligence of other species having never come closer to one of them than the pages of the National Geographic. It becomes a sort of theology science, Aristotelian style without need of theory-confounding observations.

EDTDecember 7, 2006 8:54 PM

Look science should not be tought in public schools if relegion can't be talked about. They are both virtually the same thing. They both are based on evidence which leads to my theory of relegions and science fighting because they know they both stand on the same common ground but are to afraid to open up and say " hey what the heck maybe your right" for once instead of constantly saying the stupid excuse " no science is not relegion it is based on facts." Yes geniouses it is based on facts but the key word in there is BASED on facts. Get it? Stop fighting and freaking listen to eachother and then maybe then you will find some answeres instead of being so stubborn. And no by saying this I am not saying Relegion can not be flawed either, because the fact of the matter is it can and most are. Well in my opinion every system ever made is flawed and there will never be a perfect system. Math probobly has it's deep flaws such as infinaty. I consider that a flaw because nobody really knows what it is and nobody will ever know what it is because IT dosnt exist. Infinity is just somthing to fill in the gap of never ending numbers. Im only 13 years old and you have to admit this makes since.

EDT2December 13, 2006 11:20 PM

Maybe evolution is switching from something random or nuanced, or even divine... To something methodical, starting with US. Changing DNA scientifically and trying things that nature would take millions of years to test out, within some of our lifetimes. You had some good points EDT, save your post, and look back at it in 10-20 years.

You might also be dyslexic (as I am, or is it as am I? :).

Science is based on the observed, religion is usually based on faith, but both apples and oranges are fruits that can be rotten or tasty at times.

jojoAugust 16, 2007 5:43 PM

Evolution is king - we may think intelligence is important (and it is to us - humans) however, we cold be wiped out, - just like the dionasaurs. Squids would probably be still around - so in the hierarcy of 'things' who would be smiling then? Let's not measure and gloat about one thing being 'more intelligent' than another. Brain power is only relevant if you are intelligent. If you not, (intelli)but you're a survivor, then you're smiling. We all need each other - team work is the way to look at it. use only what you need, look after others and treat all things as you would like to be treated. In other words - RESPECT. Just as you need a 20 stone beefcake at the bottom of the piramid and a 5 stone fairy at the top, so the chain-of-life relies on evolution. If we humans mess things up, the world will carry on without us - we only think we are running things, but the news for those who dont realise it , is.... we're not! We are only here but for the grace of evolution... is that what some call GOD? Maybe it is? What say u?

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