Small, Big-Brained Animals Dodge Extinction 85
ananyo writes "Large-brained animals may be less likely to go extinct in a changing world, perhaps because they can use their greater intelligence to adapt their behavior to new conditions, according to an analysis presented to a meeting of conservation biologists this week. Plotting brain size against body size creates a tidy curve. But some species have bigger or smaller brains than the curve would predict for their body size. And a bigger brain-to-body-size ratio usually means a smarter animal. The researchers looked at the sizes of such deviations from the curve and their relationships to the fates of two groups of mammalian species — 'palaeo' and 'modern'. Analysis of each group produced similar results: species that weighed less than 10 kilograms and had big brains for their body size were less likely to have gone extinct or be placed on the International Union for Conservation of Nature red list for endangered species. For species larger than about 10 kilograms, the advantage of having a large brain seems to be swamped by the disadvantage of being big — such as attracting the unwelcome attention of humans."
Two ways of surviving changes (Score:2)
One of the ways was already outlined by TFA - using intelligence to adapt their behavior to the changing environment
The other way is to evolve, and to evolve very very rapidly - in a shotgun approach - to ensure that _some_ of the offsprings, no matter how much they have changed, would made it through
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at least as measured by IQ
This is the most important part... Don't forget that our definition of intelligence today might be very different from the original "natural" one, as in "surviving in a wild environment". Maybe the bigger brain is better suited for the wildlife thing; from TFA: "Animals with larger brains relative to their body size have been shown to be more likely to thrive when introduced to new places"
On an another subject, I cannot find the curve they're referring to, to predict the brain size from the body's. From wh
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Take a look at sharks: they got massive brains, comparable to mammals of similar sizes, and were able to survive mostly unchanged for 450 million years. That's older than land animals exist.
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Take a look at sharks: they got massive brains, comparable to mammals of similar sizes, and were able to survive mostly unchanged for 450 million years. That's older than land animals exist.
The lasers provide a survival advantage.
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Not smart enough to grow bones let alone legs and evolve into politicians. You got a point, sharks are dumb. Inability to adapt to modern needs and further the species up the food chain would make them the equivalent of todays Repubmocrats and their analogs worldwide.
Re:Except (Score:4, Funny)
Penalty! Invalid politicization of scientific debate - five minutes in the penalty box!
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Not true. Nearly two-thirds of the U.S. Senate are sharks. [answers.com]
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Shark brains are tiny, but their distributed nervous system is perhaps more autonomous and substantial than mammalian ones. I've had a dogfish (small Atlantic shark) wiggle off the cutting board and swim away well after I had head and gutted it. When you eat their fresh meat it squirms when you bite it. Mako has a significantly bigger brain than a blue shark, but they're both much smaller than a deer's brain.
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At that point, scatological testing points up evidence of those individuals who feed themselves well enough to live long lives and thus a rudimentary intelligence just a bit higher than the benchmark. No shit....
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Actualy the important bit is that brain burns a lot of energy which is why we don't see smart animals everywhere. Given similar body weight, having more of that weight occupied by brain means that the animal has evolved with greater importance of inteligence (larger brain needs more energy) but just because inteligence is more imporant compared to other similaranimals doesn't mean there's more of it than a larger animal would have. Anyway, the point stands - inteligence helps to survive, at least as long as
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As other people have pointed out, this isn't necessarily a good measure. If two animals have the same brain size and one is smaller, it doesn't mean the smaller one is smarter.
A better measure may just be the number of neurons in the cerebral cortex. See this list [wikipedia.org] for example. Humans come out on top by this definition, even though whales have much bigger brains.
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It's not about brain size alone though.
From the Summary
"And a bigger brain-to-body-size ratio usually means a smarter animal"
Intelligence isn't even mentioned, behavioural flexibility is.
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You have to look at it in aggregate the way the study is. Groups of individuals wiped out in natural disasters are just that individuals. Humans survive those disasters because our big brains have enabled large populations of us to live outside what might be considered our most natural habitat. That geographic diversity has protected us as a species from natural disasters.
Your fish example is kinda the same issue. No individual fish however smart is going to be able to cope with the lake going totally dry. However smarter fish might be able to last longer in a lake with changing ecology and shrinking size, during a severe drought, and therefore survive until the rains come. While other species in the lake might die out.
A fish might migrate to a new lake when they are joined by floods. When they separate again a smarter fish species might be better equipped to adapt to the environment of the new lake, colonizing it successfully where other species might have failed. That might enable it to survive as a species even after the first lake dries up.
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But if you are suggesting brain power as a driving evolutionary force, then this fails to explain that large brains are a fairly "recent" development in evolutionary time.
Large brains are not a recent development (think cephalopods and sharks.)
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So human populations that are wiped out by disease or natural disaster are not smart enough to survive and if we look hard enough humans who have survived have bigger brains?
In the spans of centuries or even millenia? No. In the millions-long time spans from the early Homo species to the precent? Very likely.
There are plenty of variables that go into determining whether a species becomes extinct or not.
True. Glaciation, desertification, plagues. Barring sudden, catastrophic events, like the Toba supervolcanic eruption event, most of these variables are gradual, taking millenia to occur. That is the general case, and in the general case the ability to cope with such events, be it by physical or behavioral/intelligence adaptations is what matters. In the case of Human evolu
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Intelligence dictates behavior, what's the problem with the correlation?
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More intelligence does not directly tie to behavioural flexibility. Many highly intelligent people are very rigid in their doctrine, refusing to adapt. Many highly intelligent people also overspecialise(As the quote goes: Overspecialise and you breed in weakness).
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No , but it ties to a probable pallet of behavioral choices. You use only the tools you have available.
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It dictates a pallet of probable behaviors. You only use the tools you have. Success, morality and ability are an oddly Freudian assumption. Have you been bothered by these gang bangers? Do you feel somehow intimidated by ethnic men? Are you in the demographic of middle aged men? Do you consider your self virile and an active breeder? What was your relationship with your father like before you left home? Your mother?
You seem to be an angry person, with a bit of work we can bring catharsis and send you on yo
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RELATIVE brain size is closely correlated with intelligence - not absolute brain size. The brain size of a whale is MUCH larger than yours, but that is because it has a lot more body to regulate. Dolphins have larger brains than humans and much larger than chimps, and while they obviously have some intelligence, there is no evidence that they are more intelligent than humans or chimps.
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Yeah, because brain size alone is directly equivalent to intelligence. I would venture that the authors of this study have rather small brains.
It's pretty well correlated if you compare the ratio of body:brain.
Which they're doing. It even says so in the summary.
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> I do not thing size matters at all actually.
In your case I'm inclined to agree.
The main reason for going extinct: (Score:1)
Being tasty.
Re:The main reason for going extinct: (Score:5, Insightful)
A Modest Porpoisal [colbertnation.com]
Snake meat tastes much better than chicken meat (Score:2)
Chickens and cows as species are doing phenomenal with no end in the foreseeable future for the sole reason that they are tasty
If taste is the only criteria, snakes taste much better than chickens !!
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I think I had snake once, and it was really quite tasty. I don't know which kind it was, or indeed if it really was a snake. The idea of snake farming is rather amusing though, especially if there's a risk/reward factor there. Is there a golden taste-to-poison ratio?
Re:Snake meat tastes much better than chicken meat (Score:5, Informative)
I think I had snake once, and it was really quite tasty. I don't know which kind it was, or indeed if it really was a snake. The idea of snake farming is rather amusing though, especially if there's a risk/reward factor there. Is there a golden taste-to-poison ratio?
While there are many species of venomous snakes there are vey few species of poisonous ones. Many kinds of snake venom can be ingested. The venom will not kill you (unless you have a wound in your mouth) but it may make you throw up. That's why you can suck snake venom from a wound without dying yourself.
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Furthermore, most snakes have their poison glands near their mouths. The actual meat/body of the snake isn't saturated in poison, although I assume they might have some resistance to it.
Re:Snake meat tastes much better than chicken meat (Score:4, Informative)
Do NOT cut and suck. Cutting into the bite site can damage underlying organs, increase the risk of infection, and sucking on the bite site does not result in venom removal. [emedicinehealth.com]
Incising (cutting) and suctioning the bite area has not been shown to be beneficial, but a venom extractor (found in commercial snake bite kits) may be helpful if it is applied to the area within five minutes of the bite and left in place for 30 minutes. A 2004 study of mock venom extraction using a suction device, however, questioned the validity of venom extractors and suggested that their use is unlikely to be effective. [medicinenet.com]
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Cows, chicken, pigs have parasites. (Score:3)
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Except there are far far more examples of species we drove to extinction because we liked them.
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Think of it as evolution in action....
They researched on the wrong head (Score:1)
So you should be proud of your species dominance for having a bigger penis, no matter how small in absolute term it is; chances that it's already bigger than an average chimpanzee, in relative term.
Good (Score:1)
That will explain the Japanese resilience.
Welp... (Score:2)
Well, that explains Ewoks, I guess.
Hmmm.... George Lucas was actually right about something. Has anyone measured his skull capacity recently?
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What about Jar Jar Binks?
Evolve this! (Score:1)
> "Large-brained animals may be less likely to go extinct in a changing world, perhaps because
> they can use their greater intelligence to adapt their behavior to new conditions, according to an
> analysis presented to a meeting of conservation biologists this week.
Umm, they're only figuring this out now?
Each step in evolution has involved milestones that allow a magnitude or more faster scouring of the evolution fitness gradient descent space.
Slowest
1. Random mutation due to stray neutron or copy e
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Until our Brains get too big! (Score:2)
How do bigger brains protect you.... (Score:2)
Isn't that what wiped out the dinosaurs?
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For intra-mammal comparison, once their brains get large enough, they destroy the entire planet
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Last I checked, birds had been moved under dinosauria, which means that the smaller, large-brained dinosaurs survived the C-T event quite nicely.
And if you bother to check, you'll notice that birds dominated the world for ten million years or so after the C-T event, not mammals...
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If you want to champion the case of bird
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As others have pointed out, bigger brains might allow a species to spread over a wider, more diverse area, increasing survival chances. Keep in mind, the asteroid might have killed the dinosaurs, but it took hundreds of thousands of years for them to all die out, which is obviously plenty of time for intelligent problem solving to be a useful survival skill. Global scale events aren't generally things that happen quickly, a geological eye blink yes but that's still an awfully long time.
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Oblig... (Score:2)
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heh
Neanderthals (Score:4, Interesting)
Neanderthals and a number of other extinct early hominids had brain sizes of 1600cc to 2200cc. Modern homo homo sapiens have a brain size of around 1200cc to 1500cc. Einstein's brain was around 1250cc. Sharks are the most enduring vertebrate on Earth, and have one of the lowest brain/body mass ratios. There's plenty of evidence to refute the premise.
Marris in her Nature article is implying that large brain/body ratios increase species survival likelyhood, based on comparing a "primitive" class of mammals to a "modern" one. But it could just as well be their digestive system was more adaptable, superior immune systems, etc. She started with a theoretical classification of living and extinct mammals (paleo and modern) and tried to support her theory that one has a survival advantage. This is trying to make the empirical data fit the theoretical model, and is crummy science. If one were actually interested in extinction, they should study different species and why they went extinct or not, and then build a theory based on those empirical results.
Dodge Extinction (Score:1)
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Jesus Christ! (Score:1)