Why is it that every time a journalist writes about large squid eyes, they've got to compare them to dinner plates? It's so trite. How about hubcaps? Frisbees? How about just giving the dimensions and leaving it at that? Oh, well, I've had to miss most of the live webcasts of the colossal squid anatomy lesson, just because my schedule is horrid this week, but I've caught up with some of the details, thanks to the most excellent Te Papa Blog, which has nicely fleshed out the lessons with lots of photographs.
Last night's Café Scientifique here in Morris was discussing the dumbing down of traditional media, and comparing coverage of scientific issues on TV and in newspapers (usually execrable) with new media, like blogs (which at least have the potential to actually provide depth.) I was struck by that difference here. Read the USA Today article on the colossal squid eye, which boils down to basically, "Oooh, they're big!". Then compare it to the blog entry on the colossal squid eye, written by a scientist. The latter is much more informative, and contains more specific details, and isn't afraid to challenge the reader with words longer than a single syllable.
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For your benefit I can inform you that they were referred to as "as large as basket balls" in a major Swedish newspaper.
CNN says they're as big as soccer balls.
There was a comedian who did a bit about the fact that the newspapers always compare the size of tumors to the size of fruit ("a tumor the size of a grapefruit") and compare hail to the size of sports equipment ("golfball-sized hail")...
Perhaps because 1) Frisbee is a registered trademark of the Wham-O corporation for a particular brand of flying disc. 2) Frisbees come in various sizes.
Large enough to cover your face?
Why eyes as big as dinner plates? Traditional measure. See Hans Christian Andersen - 'The Tinderbox'
Is this dumbing down of the media though? I'm young, but I always assumed they were pretty dumb all along.
Squid = dinner. Makes sense to me. One has to know if the eye will indeed fit on a dinner plate.
They are as big as 1/300 of a football field.
They're as big as a squid eye. Problem solved.
So, something like 20 square metres? :p
That's how I describe my dinner plates.
"Squid = dinner. Makes sense to me. One has to know if the eye will indeed fit on a dinner plate."
LOL!
Anybody who's lived in Oklahoma knows that hail comes in the following sizes: dime, nickel, quarter, golfball, baseball, and softball.
Giant squid eyes are the size of dinner plates for the same reason that Eohippus was the size of a fox terrier. (So was Hyracotherium.)
What do you expect from a squid slightly longer than a London bus?
Sven our local weather guessers claimed we'd have "penny sized" hail. Wash DC area.
Someone give me a link to freshen up a hazy memory:
I think it might have been a Gary Larson cartoon, with a talking dinosaur saying something like "Man, there's walnuts here the size of your brain!"
crockery seems to be the standard unit of measurement for eyes. consider "your eyes are the size of saucers!" or even "look at that eye! it's the size of a gravy-boat, less a sugar-bowl!".
Apparently, collosal squids are tasty:
I look forward to collosal calamari rings.
Calamari rings as big as Rosanne Barr's belt.
(.)(.)
So do huge squid and octopus eyes (of course I don't mean this one, which hasn't been studied well yet) have an enormous amount of innervation and receptors, or are they just big in order to focus more light on a reasonably modest number of receptors?
For that matter, do any cephalopods have the number of receptors that a human has? Or, that a hawk has, to up the comparison figure? What I have understood is that cephalopods don't see as well as we do, because although their retinas are made the "right way" for an eye, our foveas have a relatively unobstructed view (the blood vessels are kept to a minimum there), and a huge number of receptors.
Which might suggest as well that cephalopods would have much better peripheral vision than we do, since ours is restricted by blood vessels.
By the way, this measurement of the squid eye isn't composed of the dimensions we'd see in the living animal, is it? I'm guessing that it's the measurement of the entire eyeball, which is substantially greater (at least in vertebrates) than the part exposed to the world.
Glen D
http://tinyurl.com/2kxyc7
I have this picture of about 30 of them gathered around, slicing into the giant squid, with conversation like "Good heavens, Dr. Featherston, would you look at this structure here?" "It's incredible, Dr. Witters! I can't believe what we're learning! Just pass me that scalpel and a fresh plate, would you?" ... with background sounds of "Nom, nom, nom."
It's like weather forecasts when they describe hail, it's always hail the size of golf balls, small dogs or the differential on a 57 Chevy or something stupid like that.
Laelaps wrote: "CNN says they're as big as soccer balls."
See, that analogy would be lost on lots of Americans. If someone asked me how big a squid's eye is, I would say something along the lines of, "The colossal squid's eye is as big as your whole frickin' head!!!"
Dinner plates, cannon balls... it gets the point across. I do have to say it would be nice to see the actual dimensions as well since my dinner plates probably 2 inches larger in diameter than my grandma's fine china.
I agree with the dumbing down of the media. Take a look at this story from our local news trying to link the drownings of multiple young men across the country to a shadowy gang of killers who's murder sign is graffitti smiley faces.
http://kstp.com/article/stories/s421846.shtml?v=1
How many smiley faces have you seen drawn on public surfaces? The ability to forego the most basic logical test in the name of news is the biggest problem and cuts across not only science but just about everything newsworthy these days.
You need to read Terry Pratchett's Tiffany Aching books. Tiffany, an apprentice witch, researches this in some detail.
Tiffany is an inquiring child, who when she reads that (the monster) Jenny Greenteeth has eyes the size of soup plates, carefully measures soup plates to check the size.
Don't diss it. That homely comparison is the only reason I have an idea how big a fox terrier is.
This is dumbing down of the media though. I like this post, greatings.
It's like weather forecasts when they describe hail, it's always hail the size of golf balls, small dogs or the differential on a 57 Chevy or something stupid like that.
What's stupid about using golf balls?
Honestly, people, comparative descriptions of size have existed forever and fully accepted. There is no correlation to intellect here. There's enough nonsense in this world to pick on as skeptics. Do we have to start making up new issues? Stop trying to feel superior over piffles and trivialities. It's embarrassing.
"CNN says they're as big as soccer balls." See, that analogy would be lost on lots of Americans.
Sweet Feathery Smoking Jesus, what are you on about? We have vast soccer leagues (AYSO) for kids here in the States! We're the birthplace of the term "soccer mom!" I'd wager >95% of Americans know what a soccer ball is.
Not coincidentally, colossal squid dinner plates are the size of humans.
True story.
But is this dumbing down of the media, or just the media being its same dumb self its always been?
The BBC always uses the London bus scale for leviathan animals.
Yes, I watched the "squid cams" for several hours last night. Yes, I ate dinner in front of my laptop for fear of missing something cool. Yes, I am apparently now a member of Squid Geek Club. Is there a handshake I need to learn? Do we have t-shirts or members-only jackets?
The comparison with soccer balls makes sure it will be understood in the US. Here in the UK they would simply be footballs, which would imply an ovoid object to most Americans, and New Zealanders for that matter, though rugby balls are bigger ovoids.
But is this dumbing down of the media, or just the media being its same dumb self its always been?
It's much ado about nothing.
Seriously, thinking simple size comparisons are "dumbing down" is pedantry raised to mental illness status. I can picture some of you sitting on a bench in a park, rocking back and forth and muttering like Rain Man.
"Can't compare to dinner plates. Gotta give precise size. Can't compare to dinner plates. Gotta give precise size. Angstroms. Gotta give it in angstroms. Angstroms are precise. Anything less spells the downfall of civilization. Angstroms are precise. But not on Monday, definitely not on Monday."
So, something like 20 square metres? :p
Not quite a kid's meal portion of a cubic centifurlong, but maybe a skosh less than a demismidgen of a hogshead.
As big as a 53t chainring. That's my standard of measurement.
I'm Welsh and my country's claim to fame seems to be its use as a very popular unit of measurement. Apparently an area of Amazonian rainforest the size of Wales is chopped down each year. That's the classic example; there are many others.
Saying that they're as big as dinnerplates suggest that they are flat...
Would it be more accurate to say that they are as big as bowling balls?
Squid says, 'Human eyeballs are the size of snack food. Keep that in mind when you find a scuba diver.'
By the way, the blue whale is said to have the largest vertebrate eye, at 150 mm, which is the size of 15 cm (vs. the 27 cm. mentioned for the squid). Or, uh, maybe really huge hailstones.
It's not surprising that's the biggest vertebrate eye, but at 5 cm., what is reportedly the largest land animal's eye residing in an ostrich head is somewhat more surprising. OK, birds have big eyes, but so do cats, hence ostrich wouldn't have been my first guess.
Glen Davidson
http://tinyurl.com/2kxyc7
But what is it in "football fields"? (The other chosen metric.)
It's almost as big as PYGMIES + DWARFS!!!
Here, Rhode Island and Delaware end up being used as comparisons. Oh, and Texas, if it's a pretty big area.
Glen D
http://tinyurl.com/2kxyc7
I'm just waiting for the creobot to come round and tell us, "See, dinner-plate eyes are irreducibly complex! Ergo, God!"
In other news, I remember once hearing someone refer to the "tentacle-like squid giant axon". *headdesk* No, the tentacle is that *other* part of the squid...
One measure that I really dislike is "Astronomical Units" or 149,597,870,691m.
Large numbers like that are meaningless so what's wrong with 150 Gigametres?
There's nothing particularly significant about the Earth-Sun distance anyway - it's not even a constant, it varies by 60m.
Dumbing down? We should be very careful here. You are assuming there were consistent days of finely crafted journalism. Check out journalism's history and you will see that its always been sketchy at best. Sure there were the great journalists and publications we compare the others to. But they always have been and still are the exception.
I always try to check myself a bit when I start arguing how "x" has gone to hell for "y" reason. I will always remember a professor saying, "'Good 'ol days?!?' There were never 'Good 'ol Days!' Pick any 'Good 'ol Day' in human history and think about what it would be really like to live in it."
Oh, Quiet Desperation, give us our fun. We're just a bunch of geeky science nerds who like to discuss the measurements of squid eyeballs. Don't be the football jock who wants to beat us up! ;)
@47 Heather:
Exactly. Also, you ever notice how people's "good 'ol days" invariably coincide with their childhoods/young adulthoods? Of course they were good--you had little responsibility, your body was young and attractive, you were more energetic, you had your whole life ahead of you...what could have been better? ;)
Now, if only those damn young whippersnapper kids today would quit telling me that Rainbow Brite and Depeche Mode were stupid... ((shaking fist from front porch))
#47: "Dumbing down? We should be very careful here."
I agree. Let's just go with "Dumb Media". Reading the article linked, it's clear that the author didn't care, and clearly was uninterested in why anyone else would care. But she/he obviously had column inches to fill and had wasted a few minutes learning some facts, so they scribbled down the most interesting thing: squid eyes big!
It's a disease widespread through journalism, but science journalism is positively rife with it: there's simply no curiosity. Whenever any new scientific fact is ever discussed, it's almost always linked to "origin of the universe / will lead to a treatment of disease X / will make our computers faster". Boring!
Dinner plates aren't exactly a standardised unit of measurement either. Our old set was even rectangular.
Dinner plates aren't exactly a standardized unit of measurement either.
Argh! It's a newscast! Not a peer reviewed paper! Did you people learn nothing about significant digits in chemistry class? News reports about squid eyes do not require as many significant digits as the papers to be written on the squid in question.
Our old set was even rectangular.
Freaks! ;-)
Oh, Quiet Desperation, give us our fun. We're just a bunch of geeky science nerds who like to discuss the measurements of squid eyeballs. Don't be the football jock who wants to beat us up!
Well, I'm a science fan, too. Bigger than most. But sometimes you guys make me want to go hang out with the jocks because they won't hyperventilate over a harmless peccadillo of general language usage. Or use worlds like "peccadillo."
But then again, when with serious jocks, toss out who has the best pitching or passing career, or something else involving sports statistics (or "sah-tistics" as they say in Indiana), and head for the hills. ;-)
The grab bag of journalistic analogies is tragically small.
As big as freshly made key lime pies. No....toddler's birthday cakes.
Squid=Food is right! In fact, we could make a entire invertebrate/cuisine mathematical system.
I think you'll find that they are three times the size of Wales.
Ha ha, you wrote "use worlds."
No, actually I'm not writing to add more pedantry about typos to some of the bizarre concerns about comparing the size to a dinner plate--which actually isn't too bad a way to get the idea across. The "soccer ball" comparison is better for comparing roughly spherical objects, but really, writing how many centimeters or inches it is really doesn't get the idea across properly, and "dinner plates" are good enough to do so.
I don't blame people who make jokes about "hail-sized golfballs" or what-not, because after hearing those comparisons of large hail with golfballs (which really are a good comparison, and I can't think of any other analogies which would work as well, especially since golf balls are of a fixed size), one rather naturally inclines to joking about it.
It's one thing to laugh, though, quite another to suggest that good everyday comparisons are somehow inappropriate.
Glen Davidson
http://tinyurl.com/2kxyc7
i undertand that the area of Wales is measured in Wales.
Glen,
I feel it in my bones that soon an OM will follow your signature. It's also how I forcast rain or a cold front...
/i undertand that the area of Wales is measured in Wales./
You Welsh DO tend to wear a lot of corduroy.
I have mixed feelings about the whole "popular science" movement. I think it's great that interested members of the public are getting to learn about science. OTOH, I think it often is "dumbed down" unnecessarily. If I've learned anything from sites like talkorigins and posts like PZ's explanation of changes in chromosome number (which have taught me more about evolutionary biology than I've learned in my 2.5 years as a college biology major), it's that people can understand many of the basic principles of science, so long as it's explained with clarity. People seem to make the mistake of thinking that clarity = over-simplification. Nothing could be further from the truth. Also, the over-simplification of scientific concepts simply reinforces the popular notion that science is somehow "elitist" (I hate that word...).
Glen, QD, etc.
I didn't get the sense we were making fun of the dinner plate/golf ball/football fields comparisons because they were inaccurate or inappropriate--at least, not any more or less so than a number of other comparisons...rather, just because they are cliched and boring. Like the Jurassic Park raptors, we intelligent creatures get tired of jumping at the prey in the same way all the time. Eventually, we'll send a buddy around the to back door.
Anyway, I doubt anybody here is advocating a violent overthrow of the mass media to ensure that all squid eyeball and hail measurements are only reported in terms of square decimegalonians or whatever...or, is anyone? I mean, it sure would be interesting to watch.
My personal favorite, of course, is "as big as an American cockroach's ovaries...when MAGNIFIED 50 TIMES MUWAHAHAHA!!!"
True, dat. There are so many other possibilities...
The standard:
Eyes as big as dinner plates...
The literal:
Eyes 30.4 cm across...
The overwritten faux literary, with bonus portentous overtones:
Massive black eyes as wide as the harvest moon as it looms on the horizon, a cold splinter of the coming winter reflecting distantly in its yellow warmth...
Pulp fiction:
Eyes that just wouldn't quit, eyes you could fall into, eyes in which might lurk a lonely gumshoe's doom. A man could get lost in eyes like those, lost to the world, but happily lost...
Political:
Massive, all-seeing eyes, suited for sighting prey in the dim light of the abyss. Or, speaking of the abyss, sensitive enough to detect Bush's approval ratings. Or Cheney's ethical streak...
Trash culture, with contemporary reference:
Eyes as big as Britney's butt...
Gamer geek speak...
"Eyes as big as YOUR MOM'S butt!!! Ooooo sick burn..."
Oh come on! You know damn well that most Americans don't know a centimeter from a light year and that their eyes glaze over whenever they see a number bigger then what they can count on their fingers.
Of course the media has to "dumb it down". I think the dinner plate is a very apt description. What other items would an American be able to visualize better then food or tools for eating?
What other items would an American be able to visualize better then food or tools for eating?
Eyes as big as your 1.5 MPG massively overcompensating SUV's hubcaps...
Eyes as big as the flywheel on the rowing machine you bought but never use...
Quiet_Desperation
What's that in Buicks, which seems to be the referred measure for military equipment (see any reference to a SCUD missile) or in Libraries of Congress, which is universally used for data of any sort. My fave universal measure is timecubes though.
I've been wondering something.
Given that this is/was such an extraordinary creature, was there any thought to allowing it to go about its business?
It strikes me as odd that we simply kill this thing on sight with no second thought, then dismantle and analyze it as though it were a machine or something.
Thanks for any thoughts on this.
Marine scientists said the creature's eye measures 10.8 inches across, larger than a large dinner plate and the biggest animal eye on earth.
Sounds like an awful small dinner plate. I don't know where they get their dinner plates from.
@66 Kevin
From one of the articles linked to, it appears the squid "was caught accidentally by fishermen last year." Seems to imply that the scientists took advantage of a fortuitously already-dead squid (ok, not fortuitous for the squid) rather than going out hunting for it themselves.
That being said, the question about the ethics of purposely killing wild animals for research is a valid one. I'm not sure what current standards are for this.
Re killing it 'on sight with no second thought', I don't think that's such a good characterization of what happened, here. My understanding is this catch, at least, was an accident, and once it was clear what they'd brought to the surface, the NZ fisheries guy onboard the vessel involved figured it wouldn't have survived anyway. So they figured, damage done, it's an extremely interesting specimen, let's bring it up for study.
Thanks, jsn, but I don't know if OM is much of anything I'd like to be bothered with. TM didn't seem to like the idea much either...
Sure, most, but if you look at the original post (plus a few comments), it does seem to really be faulting the media for just that reason. PZ seems to think that writing the dimensions is enough, while I believe the media do well to make these comparisons. I do agree that the media could tell us more, though, especially what the scientist told us, why the squid eye is so large.
If you read "Feedback" in New Scientist, they actually poke fun at the opposite tendency, some rather creative and bizarre comparisons that their media come up with. Like weights in "blue whales" and the like. Which tends to convince me that as boring and clicheed as most US comparisons are, we probably do best to stick with them.
Frankly, I don't know how big a "hubcap" is, for one of PZ's alternatives. They do vary, and I just don't have the intuitive feel for even the hubcaps on my car that I have of a "dinner plate" (most are pretty standard, around 11 inches).
What I really do wish is that they'd tell us how far across the visible portion of the eye is (roughly, since it will likely be different in a dead squid than in a live one), since I suspect that the size of the eyeball alone is more misleading than any of the rest of the dimensions and analogies given. One report states that 10 centimeters of the eye are visible. That (well, that in inches, around four) would inform people better of really what size of eyes we're discussing here, than do any of the diameters mentioned, the soccer ball analogy, or dinner plates.
Glen D
http://tinyurl.com/2kxyc7
It was already dying. These creatures live at extreme depths and under enormous amounts of pressure. Bringing it to the surface was more then enough to kill it and unfortunately the fishing boat that caught it had no idea what they had until it surfaced.
Although it is necessary to dissect a creature to fully understand its anatomy, it is preferable to observe them in their natural habitat.
We should be grateful that the fishing boat managed to preserve it so that it could be studied and that its death would not be wasted.
I see. I didn't do my due diligence before asking that question.
Thanks for the clarification.
Here's an account that uses "beach balls" and "hubcaps" for comparison--and it's worthy in noting that one giant squid eyeball is said to have been 18":
So if 10 cm of the eye was visible from the outside of a 27 cm eyeball in the dissected squid, one would figure around 6" or more would be visible in the squid with an 18" eyeball.
Glen D
http://tinyurl.com/2kxyc7
Anyway, I doubt anybody here is advocating a violent overthrow of the mass media
And yet, oddly, I do. :-) But for far better reasons, of course.
How many Smoots to a giant squid?
OK, that was pretty geekalicious (and dated) but it had to be done.
ThirdMonkey, what was the point of your hateful, bigoted and ignorant, spittle dripping comment? If you weren't joking and are older than six years old, you need professional help.
Be grateful they weren't as big as the Round Tower in Copenhagen.
I don't think so. The main complaint is clearly that they don't offer any other information besides the clichéd comparisons:
That's the "dumbing down" part, IMO.
The Colossal Blowfish is still cooler.
*sour grapes*
*pout*
*etc*
@ #75,
its ok, Smoots are still alive and valid. I go running over that bridge.
Glen, some folks are seeing the Death Of All Journalism in the dinner plate or golf ball comparisons.
And, of course, the emotionally immature are using it to trot out their "See! This proves every single American in existence is a low grade moron!" which is the intellectual equivalent of projectile diarrhea.
I'm just saying "Nothing to see here. Move on. Slow news day."
And you folks wonder why you have little to no influence come election day.
@#56 "i undertand that the area of Wales is measured in Wales."
I thought it was measured in Whales, a Whale being 10 Buicks (1970's vintage), a Buick being 2 Harleys, a Harley being 3 tricycles, A tricycle being 1.5 skateboards, A skateboard being 3 dinner plates, and a dinnerplate being 15 calimari rings, one collosal squid eye, or 1.75 whale eyes to bring the analogy back around. Correct me if I'm wrong of course...this measurement system is nearly as difficult as the Imperial system. I think I'll go back to my little metric world now.
<otaku> Bull. Everyone knows that, among land animals, Japanese schoolgirls have the biggest eyes. </otaku>
The latest description of the eye on Yahoo uses a beachball as simile, which seems to exaggerate the proportions markedly from a standard dinner plate, unless the writer originally wrote "BIG ASS DINNER PLATE". Of course there is the problem that many journalists think 6cm=6in....
I'm sure more precise anatomical details will be forthcoming for the cephalogeeks among the Pharyngulans.
The plate comparisons bother me less than the absolutely horrific, vomit-inducingly inaccurate size charts that seem to appear in every news article concerning large squid (this one being a pleasant exception). Here's one of the worst:
http://newsimg.bbc.co.uk/media/images/39045000/gif/_39045759_colossal_s…
Makes my blood boil. This one at least gets the shapes right, but gives the CS an eight-meter mantle and a nearly bus-sized FIN:
http://newsimg.bbc.co.uk/media/images/44601000/gif/_44601628_colossal_s…
This is how it should look. I've seen this diagram in only one article and have been unable to find it again:
http://newsimg.bbc.co.uk/media/images/44601000/gif/_44601628_colossal_s…
a Whale being 10 Buicks
No, A Whale is 9.99778 Buicks. We must be precise here. This is important work! ;-)
0.5 Cubits?
(with apologies to Bill Cosby and Noah): Riiiight!
;)
Actual address of the third, least offensive pic:
http://img.photobucket.com/albums/v12/BurningHammer/_42715003_colossal_…
The latter is much more informative
And geared to an audience more specifically interested in the topic, and actively looking for more detail.
Really, do you folks honestly not *get* this? Really?
Should TV Guide print the running times of shows to the millsecond?
Ya' just had to start in on dinner plates, didn't ya. I once went on a 45 minute rant (which I'll condense here) about the use of dinner plates as a measure. It came from a comment that the moon looked the size of a dinner plate. Now for a squid's eye there's the implicit assumption that you're putting the plate next to the eye and saying "yup, 'bout the same size". Ignoring the non-standardized sizing, which I'm fine with since it's Fermi problem kind of estimation, the two are comparable in a logical sense. But the moon? No. So then the question is "at what distance". Is that dinner plate at the end of my nose, at arm's length, as seen in the dining room from the kitchen, across the street ...
Glen: That's no beachball. It's a squid eye.
PZ: It's too big to be a squid eye.
Hank: I have a very bad feeling about this.
Glen: Turn the blog around.
PZ: Yeah. I think you're right...
@81 QD:
"...some folks are seeing the Death Of All Journalism in the dinner plate or golf ball comparisons."
*looks around, confused*
@89 TheTriffid:
"Should TV Guide print the running times of shows to the millsecond?"
*throws up hands in exasperation*
You guys DO realize these are just blog comments, idle chatter, the equivalent of bullshitting over a beer at happy hour, right? This reminds me of those people who wring their hands and get upset whenever someone criticizes some scientific aspect of a movie, because it's just a MOVIE and it's not supposed to be REAL and god why don't you guys just get a LIFE!
Hey, guess what! People like to talk about stuff! Sometimes that stuff isn't really important! We like to talk about it anyway!
I mean, PZ's blog may be well-known, but this isn't exactly gonna be published in a journal somewhere. Freakin' relax.
Oh, and Jens (#82) FTW!! ;)
That's persecution!
We all deserve grants, no matter our output.
Glen D
http://tinyurl.com/2kxyc7
At least we're pretty sure why Eohippus and Hyracotherium were the same size.
> brain the size of a walnut
http://masg.org.au/wp-content/uploads/2007/11/dino.gif
(The cartoon has been edited a bit by someone since Larsen drew it)
The largest living vertebrate eye. Have a look at a few ichthyosaurs, and gaze in wonderment. Some had eyes the size of a Japanese schoolgirl, and that's no typo.
BTW, in the German-speaking part of the world, hail used to be the size of dove eggs, but so few people these days have ever seen a dove egg that the comparison seems to have largely died out...
We all deserve grants, no matter our output.
HUZZAH!!!
So do huge squid and octopus eyes (of course I don't mean this one, which hasn't been studied well yet) have an enormous amount of innervation and receptors, or are they just big in order to focus more light on a reasonably modest number of receptors?
that's a good question, but relates to an even more basic question I've been wondering about for years now:
why ARE they so big?
Just how much more light can be processed by such a gargantuan eye, and is it even relevant to how this particular beastie hunts?
would a 4" diameter eye be more than sufficient? or a 2" eye?
if gigantic eyes were really an advantage in low light situations, why don't large, deep diving mammals have gigantic eyes? Many large mesopelagic fish have large eyes, but they COULD (phsycially) have much larger eyes.
Maybe there is a developmental constraint on eyesize, such that it actually limits just how small a squid eye can be relative to body size to begin with?
Big eyes, yeah, cool. Big visual cortex compared to rest of brain, even cooler. THAT'S adaptation. And I really, really wonder if the visual cortex is solely processing visual detail or if it's developed other functions as well.
#99 Ichthyic -
Could it have something to do with the skull? Mammal's eyes are contained at least partially within the skull where a squid's eye is not restricted. They can grow much larger without having to deal with the corresponding increase/change in skull structure. Also the deep-diving mammals normally operate at or near the surface and only dive for (relatively) short periods of time.
Does the large eye size grant a wider field of view? In extreme darkness, you wouldn't want to have to move the eye around a lot in order to catch a glimpse of something. You'd want to be able to see a large area and keep still in order to maximize the photons hitting the retina. Like having a slow shutter speed on a camera, you want the camera to stay still. A larger eye might make it easier to do that.
Could the water pressure have as much to do with the size of the eye as the darkness? Maybe the eyes are compressed under normal pressure (for the squid) but expand when they are brought to the surface and the surrounding tissues are elastic enough not to tear or rupture?
Just some thoughts from a completely ignorant boob. I won't be offended if they are unworthy of response...
Could it have something to do with the skull?
could be.
Could the water pressure have as much to do with the size of the eye as the darkness?
nope. fluids are relatively incompressible.
Does the large eye size grant a wider field of view?
this has to do more with placement than size.
You'd want to be able to see a large area and keep still in order to maximize the photons hitting the retina.
different issue than field of view, but I hadn't thought of it before you mentioned it. Not sure how applicable it is, though.
Also the deep-diving mammals normally operate at or near the surface and only dive for (relatively) short periods of time.
relative to what? If they hunt (think sperm whales) in the mesopelagic, it's the lighting conditions there (not at the surface) that would shape eyesize (excluding the issue of utilizing sonar, btw).
Just some thoughts from a completely ignorant boob.
no worries. I'm an ichthyologist, and don't really spend much time studying cephalopods, so my knowledge of cephalopod eye anatomy and function is quite limited as well.
heh, the squid I have dissected and taught about were several orders of magnitude smaller than the one under discussion here.
relative to what?
Relative to the time they spend at or near the surface. And I did think of sonar but not until after I hit "post". With echo-location there would be no need for a larger eye.
Well, if there is a point of diminishing returns on photo-receptors per square centimeter then a larger eye could simply mean more total photo-receptors and thus greater light sensitivity.
This would also explain the large visual cortex. The more photo-receptors in the eye the more neural circuitry required to process the information. The fact that the visual cortex is big compared to the rest of the brain is no big surprise. You have a crap-load of photo-receptors thus a correspondingly larger visual cortex to process the visual information. But then all you need to do with that info is identify food and target it for a tentacle strike. You don't need a whole lot of grey matter to act on that info once it has been boiled down by the visual cortex. Seriously, your job is to float around perfectly still in the deep-black and wait for something nearby to be dumb enough to give off a flash of light. You don't require a whole lot of deep thinking for that.
With echo-location there would be no need for a larger eye.
OTOH, did you also forget that there are a number of deep-diving marine mammals that don't rely on sonar?
elephant seals, for example.
Well, if there is a point of diminishing returns on photo-receptors per square centimeter then a larger eye could simply mean more total photo-receptors and thus greater light sensitivity.
This would also explain the large visual cortex. The more photo-receptors in the eye the more neural circuitry required to process the information. The fact that the visual cortex is big compared to the rest of the brain is no big surprise. You have a crap-load of photo-receptors thus a correspondingly larger visual cortex to process the visual information. But then all you need to do with that info is identify food and target it for a tentacle strike. You don't need a whole lot of grey matter to act on that info once it has been boiled down by the visual cortex.
yes, but this goes back to:
just how big does an eye have to be to be sufficient for hunting at the depths these beasties hunt?
it takes energy to maintain the extra brain tissue and neurons, as well.
Good questions.
But it seems to me that the light issues might be different for the giant squid than for a lot of fish. For many of the fish, and some cephalopods, have evolved bioluminescence in some manner or other, symbiotically or otherwise, while the giant squid apparently has not, and probably would not do so. I assume they wouldn't do so because they'd have to put out a huge amount of light to see their prey, which would both consume too much energy and give ample warning to prey and predator alike.
Still, even the bioluminescent fish can't simply depend upon bio-illumination, so larger eyes would still be helpful, other things being equal. I wonder if other things are equal, though, and if eyes aren't both developmentally and metabolically expensive, as brains tend to be. As big as giant squid eyes are, they're likely not any record by body mass, and I'd guess not even by metabolic standards. I seriously doubt that they have the largest eyes per mass in any case, and perhaps not even the largest by body length.
The diameter of the tarsier's eyeball is quoted at 16 mm, with 160 mm given as the maximum length of a tarsier (85-160 mm--head and body, not including tail). That makes the tarsier's eyes rather greater in diameter compared to its length than a giant squid's eye diameter per giant squid length. You have reports of roughly half meter eyeballs in squids with 10 meter lengths. True, that includes the squids arms, but in any case those are much more relevant to costs and benefit than a tail is. One can be quite sure that by body weight, and probably by percentage metabolism, the tarsier has the bigger eyes.
I wouldn't be surprised if they're all constrained by developmental costs and by metabolic costs. The tarsier's eyes are constrained from growing further because they couldn't fit into their skulls if they were larger, and even as they are, the eyes can't move in their sockets, they're so large.
Glen Davidson
http://tinyurl.com/2kxyc7
Oh, I should just add that one reason the tarsier's eyes have to be so big is that they lack the tapetum lucidum, the reflective layer behind the retina that cats and other vertebrates which evolved from nocturnal ancestors have. They'd probably evolve to be big anyway, but they could save some developmental and metabolic costs if the designer had simply thought to use the "same design", which forgetfulness just happens to follow evolutionary patterns.
Just another "poor design" that is readily explainable via evolution, with no explanation from design.
Glen Davidson
http://tinyurl.com/2kxyc7
What are these so-called 'dinner plates' of which you all speak? I eat my dinner out of a take-out box in front of the TV like any normal Canadian.
So, are their eyes as big as a fourteen-inch primo pollo pizza, or a chorizo and goat cheese?
Hey! Stargate's on!
I assume they wouldn't do so because they'd have to put out a huge amount of light to see their prey, which would both consume too much energy and give ample warning to prey and predator alike.
technically, there are ways of producing bioluminescence that involves no direct energy production on the part of the host.
hosting bioluminescent bacteria in pockets is one way.
I wonder if other things are equal, though, and if eyes aren't both developmentally and metabolically expensive, as brains tend to be.
ditto.
As big as giant squid eyes are, they're likely not any record by body mass, and I'd guess not even by metabolic standards. I seriously doubt that they have the largest eyes per mass in any case, and perhaps not even the largest by body length.
but that might not be relevant to how physiologically expensive they are, which might be related strictly to absolute size.
...and they certainly are quite large in absolute size.
You have reports of roughly half meter eyeballs in squids with 10 meter lengths
really? that's freaking huge relative to body length alrighty, as well as being large in an absolute sense.
I wouldn't be surprised if they're all constrained by developmental costs and by metabolic costs.
hmm, I was kinda thinking developmental constraints might actually be overriding the metabolic costs in this case.
but of course that ends up boiling down to a relative cost analysis anyway, just from a different perspective: more costly to develop a new pathway than to compensate for the cost of the large eyes to begin with (hence they stay very large). Which would also work to explain why mesopelagic fish don't have even larger eyes themselves (cost of new developmental pathway to change size of skull, for example).
It's perhaps not as parsimonius, but it just struck me nonetheless.
Just another "poor design" that is readily explainable via evolution, with no explanation from design.
heh, yup.
i really appreciated that the graduate courses I took on evolutionary biology always utilized examples of exactly this type to illustrate.
kind of the "exception proves the rule" method.
It's quite possible that's the case with tarsiers (but presumably they could grow larger heads, depending...) as well as the fishes, all right.
I have the feeling that it would be rather difficult to figure out the various issues of contraints vs. costs, especially since they're intertwined to some extent anyway.
We've probably done about as much as we can from our armchairs anyway (ok, swivel chair for me), and had best leave the various options out there for someone to research in the future.
Glen Davidson
http://tinyurl.com/2kxyc7
I have the feeling that it would be rather difficult to figure out the various issues of contraints vs. costs, especially since they're intertwined to some extent anyway.
sure would be fun, though. I could envision building an entire lab around just that, as applied to just squid.
I could easily see a lab like that generating decent graduate students for at least a decade.
so many interesting questions to explore...
You should also remember our dinner plates here in NZ aren't as big as your dinner plates in the US ;)
Doing cost-benefit analysis of biological structures within a given environment in order to find points of diminishing returns?
That would be cool. Sometimes I really wish I'd gotten into biology instead of comp sci...
That would be cool. Sometimes I really wish I'd gotten into biology instead of comp sci...
When I was an undergrad, one of my friends was a 48 year old grad student in behavioral ecology.
never too late...
...In fact, both where I did my undergrad AND where I did my grad work had excellent labs studying ecological physiology and biomechanics.
I don't know if he's still there for sure (I think he is), but if you really get a jones going for the subject, you might try contacting James Childress at the University of California, Santa Barbara:
http://www.lifesci.ucsb.edu/eemb/faculty/childress/
or more related to biomechanics would be Mimi Koehl at Berkeley:
http://ib.berkeley.edu/labs/koehl/
This morning on the radio they were discussing the variety of descriptions used in the NZ media to describe the eyes. Noted were dinner plates, soccer balls and a frisbee as well as the dimensions.
PZ, I give you: The Leader from today's Guardian newspaper:
http://www.guardian.co.uk/commentisfree/2008/may/01/wildlife
Enjoy.
A question: does anyone know if this colossal squid's eye would rank as the largest eye (currently known) in the history of life on earth? I seem to vaguely recall reading somewhere about an ichthyosaur species with an eye that was 27 cm in diameter.
This just in to aye-aye witness news! Scientists have measured the size of the eye of the legendary colossal squid for the very first time! We take you know to Griz Blender who is with the scientists!
This is Griz Blender asking the scientists how big the colossal squid's eye actually is! How big is the colossal squid's eye, scientists?
Well, it's precisely twice as big as half of it.
There you have it, folks! Now back to aye-aye witness news!
Seriously, this is great news. We always thought it would be large. Now we know because we have seen. Aaahhhh! I just love the way science happens.
You guys DO realize these are just blog comments, idle chatter, the equivalent of bullshitting over a beer at happy hour, right?
No kidding, Professor Hawking. So why are my comments excluded from that set? I was just meta-bullshitting. ;-) I'm the guy at the end of the bar saying, drunkenly, "Yoush all takin it waaaay too serioushly!"
Glen: That's no beachball. It's a squid eye.
PZ: It's too big to be a squid eye.
Hank: I have a very bad feeling about this.
Glen: Turn the blog around.
PZ: Yeah. I think you're right...
Hank: I think we need a bigger boat.
Ichthyic: Farewell and adieu to you fair spanish ladies...
The size comparisons mentioned above are innocuous compared to RAW STORY's comment that the squids eye was 11 times the size of the human eye, which was 1 inch.ARRRGGGGGG
Um, no that isn't the correct usage of that old saw. The meaning of "proves" in this case is "tests", otherwise the expression makes no sense.
Um, no that isn't the correct usage of that old saw. The meaning of "proves" in this case is "tests", otherwise the expression makes no sense.
i knew someone would point that out. The problem is that even though you are technically correct as to how it is applied (especially in this case) that is not the colloquial phrase. So, I chose to utilize the colloquial phrase, knowing that most here would know what I meant. Still, I figured someone would also do what you did as well.
*shrug*
http://en.wikipedia.org/wiki/Exception_that_proves_the_rule
Wrong, I think. People I know who study elephant seals call them "surfacers" rather than "divers."
Go here and scroll down for some data.
Let's also lament the frequency with which all sharp teeth in nature are described as "razor sharp". Doesn't matter if the sharpness is due to serrations, points, or truly razor-like edges. They're always always razor sharp.
I had to Google the "Jaws" refs... sigh.
Easy: because they have sonar instead. They literally don't need to see where they're going.
Enter Janjucetus, a predatory marine mammal without sonar and with decent-sized eyes.
What do elephant seals eat, actually? Do they use their whiskers to find their prey?
Two words: Shonisaurus sikanniensis...
What do elephant seals eat, actually?
squid.
no kidding.
though there actually is a sexually dimorphic diet in those critters.
I forget which sex eats mostly squid.
Do they use their whiskers to find their prey?
you're thinking walrus. elephant seals don't have much in the way of whiskers.
http://marinebio.org/species.asp?id=295
btw:
Easy: because they have sonar instead. They literally don't need to see where they're going.
I actually found that rather insulting, though I know you didn't intend it as such; perhaps you failed to notice the references to sonar, and me actually specifically making note of it? My problem, not yours I suppose.
Here's one for you, though:
did you also know that even the ones that rely heavily on sonar also have good vision as well?
let's revisit some basics of marine mammals:
http://www.seaworld.org/infobooks/Bottlenose/sensesdol.html
I had to Google the "Jaws" refs... sigh.
no worries. I'm sure you could easily list a dozen pop culture references I wouldn't have the slightest clue about.
On elephant seals:
"these seals are able to dive very deeply for extremely long periods of time compared to other seals. Males dive to 350-800 m on average and females to 300-600 m. The dives average 13-17 minutes, longer for males, followed by a brief, [less than] 3 minute surface interval. The deepest dives for northern elephant seals were recorded at 1,500 m deep for 1.5-2 hours. These seals remain submerged 80-95% of time spent at sea....
Cephalopods are an important component of the northern elephant seal diet. Other prey includes Pacific whiting, skates, rays, sharks, and pelagic red crabs."
Actually the USA Today article and the blog post have about the same average word length. ☺