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Fear of Snakes May Have Driven Pre-Human Evolution 553

Posted by Hemos
from the snakes-on-a-plane dept.
Krishna Dagli writes "An evolutionary arms race between early snakes and mammals triggered the development of improved vision and large brains in primates, a radical new theory suggests. The idea, proposed by Lynne Isbell, an anthropologist at the University of California, Davis, suggests that snakes and primates share a long and intimate history, one that forced both groups to evolve new strategies as each attempted to gain the upper hand. Early primates developed a better eye for color, detail and movement and the ability to see in three dimensions — traits that are important for detecting threats at close range. Humans are descended from those same primates. "
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Fear of Snakes May Have Driven Pre-Human Evolution

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  • by Anonymous Coward on Monday July 24, 2006 @09:00AM (#15768821)
    Snakes...ON A PLANE
  • Finallly (Score:5, Funny)

    by LiquidCoooled (634315) on Monday July 24, 2006 @09:01AM (#15768823) Homepage Journal
    Humans are descended from those same primates.
    And lawyers/politicians/managers are descended from snakes.

    At least its an explanation of the uneasy feeling I get when I see Darl Mcbride.
  • by countach (534280) on Monday July 24, 2006 @09:01AM (#15768825)
    Genesis 3:14-15 The LORD God said to the serpent, "Because you have done this, Cursed are you more than all cattle, And more than every beast of the field; On your belly you will go, And dust you will eat All the days of your life; And I will put enmity Between you and the woman, And between your seed and her seed; He shall bruise you on the head, And you shall bruise him on the heel."
    • by Roody Blashes (975889) on Monday July 24, 2006 @09:05AM (#15768852) Homepage Journal
      Unfortunately for the bible-thumpers, this isn't actually a theory, it's just an idea. The idea that among a litany of predatory creatures human beings were primarily pushed by one - that although fear-inducing is relatively harmless on the scale of tribes and socities - is a bit of a stretch.

      If this is pursued by scientists we will likely find that, yes, there are specific factors involved in competition between humans and snakes that drove specific selections that persist in modern humans, but to suggest that all of "pre-human evolution" was driven primarily by snakes is a bit silly.
      • by operagost (62405) on Monday July 24, 2006 @09:55AM (#15769231) Homepage Journal
        Use the phrase "bible-thumpers" in your post on a scientific topic and you're sure to be modded up insightful!

        Scientist 1: How'd you like my paper on "Impact of herpetological influence on anthropological evolution?"
        Scientist 2: Bad news, dude! The "bible-thumpers" have glommed off your hypothesis! Something in Genesis about chicks stomping on snakes. Sounds fetishy. Anyway, we can't afford to lend these cretins any legitimacy. You'll have to think of something else.
        Scientist 1: Crap! Back to the drawing board. How about 'gators? They're hella scary!

    • by Anonymous Coward on Monday July 24, 2006 @09:07AM (#15768865)

      So what you are saying is that our fear of snakes caused us to incorporate them into our myths and legends as the stereotypical "bad guy"? Makes sense to me.

      • You can find an absolutely fascinating study of how the symbols of our creation myths (primarily Genesis, but others are explored fairly well) seem to reflect our actual evolutionary history in Carl Sagan's Dragons of Eden: Speculations on the Evolution of Human Intelligence [amazon.com].

        While it includes some later-disproven assertions (dinosaurs being killed off by a nearby supernova, mainly), most of it is brilliant and engrossing for anyone interested in topics like this.

        He postulates that Genesis is really the story of the evolution of human intelligence being selected for because it was necessary for us to defeat the reptiles which preyed on our ancestors. We defeated the serpents -- there are no more legged "dragon" type creatures which every human civilization remembers in legend. However, the price we paid was a separation from the animal kingdom, self-consciousness (the realization that we are naked), and most interesting to me, pain in childbirth because of our big brain-holding heads.

        Another interesting bit from the book: In every single culture in the world, the sounds "ssssssss" or "sssshhhhhhhhhh" mean "Everybody Shut Up!", as in, "Quiet! Snake!".

        It's a good, quick read. I enjoyed it on a Lufthansa flight from Philly to Frankfurt a few years ago. Highly recommended.

    • by Black Parrot (19622) on Monday July 24, 2006 @09:12AM (#15768900)
      Uhmmm... the hypothesis, even if correct, doesn't say that snakes lost their legs due to meddling in the affairs of a couple of innocent humans.
    • by arivanov (12034) on Monday July 24, 2006 @09:24AM (#15768987) Homepage
      I had the same thought at first.

      At second - another thought. Birds of prey. Keeping alive from them requires similar improvements in vision. It also requires much more.

      Current primates do not cooperate to defend against snakes. At the same time they cooperate even on interspecies level to keep track and warn the pack about forest eagles. There is some extremely good footage narrated by David Attenborough on that (forgot in which one of his movies). The most important characteristic of primates is their socialness. In fact the size of a primate brain for the lower primates is directly proportional to the group size (once again quoting Attenborough).

      So the primary driver in primate development should be the predators which improved their pack social cohesion and group communication. Eagles, tree mammal predators from the polecat family and to some extent cats.

      Not snakes.

      • FTFA,
        predatory birds evolved much later than snakes, after primates developed steroscopic vision.
      • I always thought that 3D vision was an evolution for predators to be able to calculate distance from their prey to their current position. And pray has eyes on the sides because it allows them to have a bigger span of vision to catch those predators when coming.

        Now, for the color, I thought it was a trait for some fruit-picker beings, to be able to recognize good fruits from bad ones.

        I never imagined it was for the snakes :P
    • by hey! (33014) on Monday July 24, 2006 @09:36AM (#15769088) Homepage Journal
      My mind leapt to Genesis as well.

      The thing is, the snake is by no means a uniformly malign figure in mythology. Quite the opposite; they are often beneficent. The snake has other symbolic potentials, with its ability to shed its skin (rebirth) and to form a circle by biting its tail (eternity).

      Chinese dragons are conspicuously snake-like, and share the common mythical snake role as bringers of wisdom. In fact Genesis, if you read it closely, is clearly a compilation of myths. It is clear that in the source material for the temptation story, the snake plays exactly the bringer of wisdom role in the story ("Now the serpent was more subtil than any beast of the field which the LORD God had made." Gen 3:1). But with irony that is a particular characteristic of Jewish scripture, that gift is a source of misfortune.

      Stories of dual natured gifts are not uncommon in folklore and myth. The point of these stories is pretty much the same: life is full of pain and toil, then you die. But on the other hand if you could choose otherwise, there would be a price you might not be so happy to pay: without death children are not born, illness and suffering does not end. Wisdom is a particular source of pain, but as the generations of scribes and their successor Talmudists, it's also a source or pleasure and comfort. There is no wisdom without toil and suffering.

      Our way of looking at these stories, Genesis in particular, has been diminished by religious ideology. To the point that those of us raised in the Judeo-Christian tradition think nothing is more natural than to hate and revile snakes. The snake figure in Genesis was never equated with Satan until a much later date. "Satan" comes from the Hebrew word for "obstacle" or "adversary". Read carefully: the snake's part in the story puts enmity between him and humanity, but it does not unambigiously put him in the role of The Enemy; he could equally be seen as a tragic figure that nudged humanity down an alternative path of pain and enlightenment.

      In any case, to bring this back to the topic at hand, it is certainly not the case the myth and religion can be used to show an atavistic revulsion to snakes that may have an evolutionary basis.
      • Our way of looking at these stories, Genesis in particular, has been diminished by religious ideology. To the point that those of us raised in the Judeo-Christian tradition think nothing is more natural than to hate and revile snakes.
        No kidding! After last week's fellowship, we all ran into the woods and started beating the suckers with sticks! Evil little beasties!
      • by operagost (62405) on Monday July 24, 2006 @10:05AM (#15769298) Homepage Journal
        I forgot to add something else to the thread.
        But on the other hand if you could choose otherwise, there would be a price you might not be so happy to pay: without death children are not born, illness and suffering does not end.
        In Genesis 2, God says that he will "greatly increase" woman's pain in childbearing. Clearly, children were being conceived and born in Eden. Also, Eden is the definition of Utopia, and no trace of illness or suffering are to be found. Perhaps you do not find eternal life to be palatable, but the entire Judeo-Christian theology revolves around it (save for the Sadducees, whose position Jesus soundly refuted).
        • In Genesis 2, God says that he will "greatly increase" woman's pain in childbearing. Clearly, children were being conceived and born in Eden. Also, Eden is the definition of Utopia, and no trace of illness or suffering are to be found. Perhaps you do not find eternal life to be palatable, but the entire Judeo-Christian theology revolves around it (save for the Sadducees, whose position Jesus soundly refuted).

          I understand this is an internally self-consistent position.

          However, since we don't have a choice ab
      • My mind leapt to Genesis as well
        Me too, I can feel it coming in the air tonight, oh Lord.
    • by digitalhermit (113459) on Monday July 24, 2006 @09:37AM (#15769101) Homepage
      Of course it may only be coincidence that pre-Christian civilizations worshipped snakes... These civilizations saw the annual re-birth of the snake (via shedding its skin) as somehow divine. It may also be coincidence that the bull (horns, cloven feet) was also worshipped by pre-Christian civilizations. Or not so coincidental. Nothing like making the god of the old religion the icon of evil, eh?

      Of course, this didn't always happen. In many cases the beliefs and rituals of the previous civiliation were modified by Christianity. It's not just coincidental -- almost all civilizations/religions have a feast time at the end of winter, end of harvest, during the winter. There are *human* reasons for this. Most times it's either for rationalizing the unknown or just an excuse to feast. So we have Christian feasts that coincide with the Saturnalia and other ancient ceremonies. Maybe when we sit down for a Christmas dinner some ancient god nods and thanks us for remembering. Maybe when we recognize the Resurrection of Christ some primal force awakens and pushes the new plants out.

      But back to snakes. The story of Genesis is old and borrows heavily from previous traditions. To condemn the snake by selecting one reference is wrong though, as the snake/serpent is considered wise throughout other books in *YOUR* Bible (E.g., John 3:14). Read your Book!

  • by tsa (15680) on Monday July 24, 2006 @09:05AM (#15768853) Homepage
    1. Dream up a far-fetched 'theory' that Joe public can understand and involves strong emotions
    2. Seek publicity
    3. ....
    4. Profit!
  • Conventional wisdom (Score:5, Interesting)

    by Black Parrot (19622) on Monday July 24, 2006 @09:09AM (#15768876)
    Conventional wisdom is that our depth perception and improved color vision supported an arboreal fruit-eating lifestyle.

    It's not obvious why our lineage would co-evolve with snakes any more than any other mammalian lineage would.

    BTW, "improved color vision" is relative. Birds have receptors for four colors rather than three. Early mammals lost two of the four, which is why your dog is "color blind". Our lineage re-gained a third, though not the same as either of the two that our ancestors had lost. There was an article about this in Scientific American a month or two back.
    • by dreamchaser (49529) on Monday July 24, 2006 @09:16AM (#15768919) Homepage Journal
      Addressed somewhat in the article (yes I actually read it).

      Scientists had previously thought that these traits evolved together as primates used their hands and eyes to grab insects, or pick fruit or to swing through trees, but recent discoveries from neuroscience are casting doubt on these theories.
    • by B3ryllium (571199) on Monday July 24, 2006 @09:27AM (#15769014) Homepage
      Our lineage re-gained a third

      Some people also have a fourth, I've heard.
      • by arete (170676) <.ten.gix. .ta. .2todhsalsetera.> on Monday July 24, 2006 @09:55AM (#15769229) Homepage
        To my knowledge - which is admittedly a year or so old - basically there are three relevant points.

        1. Most people have 3 color receptors that they actually use, while some are colorblind to varying degrees including a relatively high number are red-green colorblind having effectively one RG and one B receptor. HOWEVER, where (what wavelength) the "R" "G" and "B" receptors is is NOT exactly the same for each person. So it is very possible that a perfect match for one person is not a perfect match for another especially for colors that are a complex mixture of wavelengths (eg most real-life pigments in sunlight) Note that generally matching the amount of the same pigment should generally be very, very close - to demonstrate this effect you mostly need to be combining very different wavelengths that "should" be the same added together.

        The take-home geek message is that you can use an RGB monitor to match every color you can see - IF the monitor's RGB match yours. Otherwise it's not perfect. (Also see point 3)

        Have two receptors very close together eventually becomes indistinguishable from just having one as they approach being in the same spot.

        2. Some people are known as "tetrachromats" All examples I've heard about have been the mothers of red-green colorblind men. Essentially they have an extra receptor between R & G. This means that they can determine that two colors don't match in situations where everyone with three receptors would think they matched.

        3. Apparently we may also have a 4th (or 5th, depending on pt 2) receptor in the ultraviolet range. However, most of the light in this range is blocked by the alchohol in our eye fluids, so this receptor is mostly pretty useless. However, this doesn't mean we don't see SOME color with this receptor right at the edge where it's not blocked by the alchohol - it's just not a very large part of our sight.

        These colors definitely don't exist in monitors, which I personally and nonscientifically think is why I love staring at the LED on a PS2.

        • by Valdrax (32670) on Monday July 24, 2006 @01:24PM (#15770833)
          Some people are known as "tetrachromats" All examples I've heard about have been the mothers of red-green colorblind men. Essentially they have an extra receptor between R & G.

          Actually, it's more interesting than that. There are variant genes for the red & green cones that result in the cones absorbing a slightly different spectrum of light. The genes for this are on the X chromosome. A tetrachromat is a woman who has differing genes on her two differing X chromosomes that are somehow both active, leading to either her red cones or her green cones being split between the two variant alleles and allowing for finer detail in distinguishing shades of red or green.

          Why I say it's more interesting is that this shows us that beyond the perceptual, cognitive differences between perception of color that we grow up with within our cultures, humans actually have differing physical hardware for perceiving color. We really don't see the world with the same eyes.

          Apparently we may also have a 4th (or 5th, depending on pt 2) receptor in the ultraviolet range. However, most of the light in this range is blocked by the alchohol in our eye fluids, so this receptor is mostly pretty useless.

          Actually, it's just that our blue cones and our rods have sensitivity in the near UV range. It's the lens of the eye that blocks UV; there's no alcohol in the vitreous humour. People who have cataract surgery that replaces their lens can sometimes see UV in a very limited fashion.

          You can read more about aphakia and UV sensitivity here. [guardian.co.uk]
    • Well, the article says that recent research shows that reach-and-grasp did not evolve at the same time as the better vision, which makes it unlikely that they evolved for the same purpose. I'm not sold on this, as competitive advantage in food-gathering would still exist, IMO.

      It's not obvious why our lineage would co-evolve with snakes any more than any other mammalian lineage would.

      One obvious reason to me would be habitat. Maybe the primate lineage occupied the same areas as snakes? Maybe other ma
      • > Well, the article says that recent research shows that reach-and-grasp did not evolve at the same time as the better vision, which makes it unlikely that they evolved for the same purpose.

        I'm not sure that's a good argument. It's not like evolution happens on demand.

        Our own upright posture, opposable thumbs, and big brains didn't all evolve at the same time, but we still build our lifestyle around their conjunction.

    • To be pedantic, we mutated two more, green and blue. Ten percent of the population have an extra green, making four total and ripe for another mutation.
  • They...they couldn't see in 3 dimensions before? ...Could we evolve to see 4 dimensions, then?
    • Only with more, bigger and better snakes, obviously.

      Let the evolution race begin!
    • Re:2D-3D? (Score:2, Informative)

      by Roody Blashes (975889)
      You don't see in 3 dimensions now, you MOVE in 3 dimensions and you SEE in 2. If you could see in 3 dimensions you'd be awfully confused, because you'd be able to see every side of every object in your field of view.

      Theoretically, this would not be possible anyway given our current configuration and understanding of light. To be able to see in 3d, you'd have to somehow pick up light that was being deflected away from your eyes, or that was blocked by foreground objects in your field of vision.
      • Re:2D-3D? (Score:3, Informative)

        by AndersOSU (873247)
        I'm pretty sure you knew this, but seing in three dimensions means having stereoscopic vision, and the benifits of much improved depth perception.
        • Re:2D-3D? (Score:3, Insightful)

          by Roody Blashes (975889)
          Within the context of the original post (the evolving to see in 4 dimensions thing), it suggests to me that he meant seeing all 3 spacial dimensions. Stereoscopic vision is not the same as that. It just means your brain is capable of recognizing angles on objects and interpreting them for you as some level of depth. People with poor depth perception don't necessarily have anything wrong with their eyes. They see the same thing everyone else does, their brains just don't interpret the angles properly.

          You can
          • Re:2D-3D? (Score:3, Funny)

            by operagost (62405)
            You can prove quite easily that you can only see two dimensions of space. Simply place a cube on a table, lower and center your vision so it's pinpointed right in the center of one side, and note that you see a square, not a cube. Without the angles to suggest depth, you're not capable of perceiving three dimensions at all.
            Speak for yourself!

            - Picasso

        • Re:2D-3D? (Score:3, Insightful)

          by Fordiman (689627)
          No. Stereoscopic vision gives you the ability to percieve distance in a 3d environment. You're still only /seeing/ in 2-d. Specifically, two 2-d images. The 3-d you percieve is those two images as processed by your brain.

          Hence percieve, not see.
    • Re:2D-3D? (Score:2, Interesting)

      by LiquidCoooled (634315)
      I can already see in four dimensions.
      Your memory stores information about the passing of time and so you can see what something used to look like and how it looks now.

      For an often strange example, go and visit your childhood neighbourhood and you will see all the things that have changed since.
    • by pla (258480)
      They...they couldn't see in 3 dimensions before? ...Could we evolve to see 4 dimensions, then?

      Think of it like this... When you look at a photograph, a 2d captured moment, you can still consciously determine what lies closer or further than a given point most of the time. Some unusual lighting effects or geometry may throw you off, but you know the tiny tree belongs much further away than the giant mouse in the foreground.

      Now extend that to 4d perception - Our eyes give us a pseudo-3d snapshot of the
  • Why snakes? (Score:5, Interesting)

    by triskaidekaphile (252815) <xerafin@hotmail.com> on Monday July 24, 2006 @09:12AM (#15768897) Homepage
    Did the primates have no other predators? As I recall, binocular vision is a characteristic of predator, not prey. (How far do I have to run or jump to catch dinner?) Motion detection and wide-field vision are a characteristic of prey, not predator. (Is something about to run or jump on me? Maybe a moderator with points?)
    • accurately gauging distance can be a very good thing when leaping from tree to tree (at least... I imagine so. I'm not a biologist or something, but it's the first idea I had)
    • Re:Why snakes? (Score:3, Informative)

      by swv3752 (187722)
      The big cats, particularly the cave lion and sabertooth tiger preyed on early man. There have been a number of skulls of early man found with holes in the cranium consistent with the fangs of the big cats. Of course this article is talking about time before there was big cats. There would have been crocs and proto-birds. The crocs and birds would have driven motion sensing. Our motion sensing is so strong that we flick our eyes aboutconstantly to create a pseudo-motion so that we can see properly.
  • I wonder what other deep-rooted, genetic fears we have... I know that snakes in the wild give me that weird chill on the back of my neck. So does hearing tigers. Lions sound different and they don't have the same effect, but hearing a tiger growl I guess triggers some primal fear. Maybe it's that these animals -- snakes and tigers -- can kill you without you ever knowing you're in danger. Imagine a snake biting you, injecting venom, then sitting there waiting until you finally kick the bucket. I can imagin
    • Plus humans suck at fighting. We have soft underbellies, no claws, no proper teeth, our reproductive organs hang out in plain sight, we can't run fast, we can't climb trees quickly, our sense of smell sucks.

      Sure, but unlike any of the other predators mentioned in this discussion, we make tools, and we're also much better at building shelters and forming communities for mutual benefit. A man vs. a tiger isn't a fair fight, but a dozen men with good firearms in vehicles vs. a tiger also isn't a fair fight

    • Snakes, spiders, water, heights are genetically-enabled fears that all primates share if they are imprinted. The mechanism has been demonstrated on monkeys and chimpanzees. If you show a young chimpanzee a snake for the first time, and show him other chimpanzees expressing fear, the youngster develops a fear of snakes. If you show him chimpanzees ignoring the snake, he does not. We know it's a genetic function because the same does not happen with a flower, a chair, etc.

      It makes sense because there's no
  • This Idea = Bogus (Score:5, Interesting)

    by Anonymous Coward on Monday July 24, 2006 @09:18AM (#15768936)
    I *am* a psychologist / scientist that studies vision, and I can happily report that this material is a) not new [see the bogus theoretical ramblings of Mineka on the subject] and b) not in any way factual.

    Why should the threat of consumption from snakes (snakes! of all things!) have driven us to evolve incredibly good eyesight? Why not hearing? Why not some more obvious and simple snake defense mechanism (like, immunity from snake poison?) At no time in our evolutionary history did snakes actually represent a dominant predatory force (To deal with this, some "experts" claim generalization from dinosaur tails. Right). Just because it has the word "evolution" in it doesn't mean it's right.

    This idea, and almost every instantiation of this idea, is total crap, and should be treated this way.
    • Re:This Idea = Bogus (Score:3, Informative)

      by hey! (33014)

      Why should the threat of consumption from snakes (snakes! of all things!) have driven us to evolve incredibly good eyesight? Why not hearing? Why not some more obvious and simple snake defense mechanism (like, immunity from snake poison?)


      Because evolution does not provide an organism with what it needs to survive and reproduce. The organism takes what it gets from the mutation lottery and does the best it can.

      However, I agree, it seems very unlikely that snakes could be an explanatory factor in the develop
    • Why not some more obvious and simple snake defense mechanism (like, immunity from snake poison?)

      The majority of snakes that feasibly can eat humans (think anacondas, burmese pythons, reticulated pythons, and perhaps scrub pythons) are not venomous but constrictors. While venomous snakes will attack us out of defense if threatened, to my knowledge, none of them are large enough to eat us, and thus it is unlikely that they would seek us out with the intention of killing us, unlike the aforementioned species.
    • by Shadowlore (10860) on Monday July 24, 2006 @01:23PM (#15770821) Journal
      Why should the threat of consumption from snakes (snakes! of all things!) have driven us to evolve incredibly good eyesight? Why not hearing? Why not some more obvious and simple snake defense mechanism (like, immunity from snake poison?) At no time in our evolutionary history did snakes actually represent a dominant predatory force (To deal with this, some "experts" claim generalization from dinosaur tails. Right). Just because it has the word "evolution" in it doesn't mean it's right.


      Regarding your idea of evolution, I'll paraphrase you:
      "The idea the evolution was a conscious process, and almost every instantiation of this idea, is total crap, and should be treated this way."

      You, like millions of others, make a mistake in thinking evolution is a conscious process. With genetic manipulation it may become that way in humans, but otherwise it is not. It isn't like the proto-humans/early humans sat around and said "You know these snakes are a deadly threat. We shall form a comittee and decide on how best to evolve to defeat them.". If that had happened we would have snake venom immunity.[1]

      IF snakes were a deadly threat, than whatever provided an advantage in escaping the threat would have sufficed. If better vision provided "good enough" advantage for the being with those genes to pass on their DNA then that would happen (with regard to that threat). It could well be that several advantages produced a set of genes that provided multiple avenues of threat avoidance. Particularly if these advantages were useful for more than snakes.

      Evolution is explanatory, not proactive. Yet. Sadly, scientists working in the field often use stupid and ridiculous statemets such as "in response to" when they should be saying "as a result of...". The headline for the article here on /. also reflects this lack of understanding.

      If conceived of today evolution would be termed an "emergent phenomenon". The primary principle of evolution is "good enough". If it works, it works - that is all that is required. There is no planning, no intentional process.

      Regarding snakes being a threat ... you who live your your comfy controlled environment may not regard snakes as a threat. However, thos eof us who have had to live and work in open areas with posionous snakes know otherwise. Snakes are particularly deadly to smaller bodies such as children. Whether it be poisonous snakes or constrictors, if snakes are taking out younglings that lack the ability to get away (lack of perception, speed, recognition, whatever) then they certainly would be a factor in the evolution of creatures they consume.

      1) Venom immunity would not have sufficed. What good is immunity to venom if the wounds get infected and you die from infection? A Committe would have produced venom immunity and then we'd have died out from secondary snake bite infections. A clear example of the phrase "to each and every problem there is solution that is simple and obvious. Said answer is also wrong."

      Hearing would have been a likewise poor choice given the sensitivity and limited range of perception it would have produced. Early humans occupied multiple niches and thus were open to many predators of a wide range of "features".
  • by bunbuntheminilop (935594) on Monday July 24, 2006 @09:22AM (#15768970)
    ...a snake participates in an arms race, I'll never know.
  • Bullshit (Score:3, Interesting)

    by dargaud (518470) <slashdot2@gd a r g a ud.net> on Monday July 24, 2006 @09:25AM (#15768991) Homepage
    Why are there such bullshit theories regularly sprouting in the news ? Either the summary is (very) bad, or the theory itself is. It's so obvious that there are _many_ factors guiding the evolution of several _sets_ of species like that. And snakes don't eat primates (except for a few exceptions). They only bite when threatened or scared, so I don't see how this could be a leading evolutionary factor.
    • Yeah but if you're reaching for a piece of fruit in a tree and don't see the snake, you get bitten and maybe die. The snake will just sit there trying to to be seen and this damn monkey will keep reaching for it, so it'll bite in self-defense. There's an evolutionary pressure towards being able to spot the snake.

      Now a clever monkey, maybe having seen some relatives die of snake bites, might decide to squash the snake with a rock. Or maybe it would think that the snake would be a better meal than that piec

      • It's still, at best, blatant conjecture. You could also make the same exact case for every predator alive at the time - so why is this new ability not to avoid lions, leopards, eagles, etc., all of which were known to prey on humans?

        In other words, 1) there's no evidence, and 2) there's no uniqueness to snakes. So this theory needs to go back to the drawing board.
  • The key to TFA is recent research that demonstrates that reach-and-grasp didn't evolve alongside 3D vision. So the question this theory attempts to answer is, "Why did early primates evolve advanced, close-up, 3D vision?"

    As with most things, the simplest answer is usually the best. While predator evasion could very likely be part of it, there is also an advantage in food gathering -- and while this good vision didn't co-evolve with reach-and-grasp ability, it's quite possible that once reach-and grasp ev
  • Far-fetched. (Score:5, Interesting)

    by Ihlosi (895663) on Monday July 24, 2006 @09:29AM (#15769024)
    suggests that snakes and primates share a long and intimate history, one that forced both groups to evolve new strategies as each attempted to gain the upper hand.



    That's quite far-fetched. Snakes and primates do not strongly compete for the same food source and do not really have a strong predator/prey relationship. In fact, they can get along quite well as long as they stay out of each other's way.



    The primates' evolutionary developments might have other, much more direct reasons. Color perception is directly related to gathering food (red and yellow fruit vs. green leaves. Btw, picking strawberries is quite a pain in the ass if you're colorblind). Depth perception is pretty much a necessity when jumping from tree to tree - natural selection manifests quite quickly and painfully here. Being able to perceive movements ... well, primates are somewhere in the middle of the road here. They don't perceive ultra-slow movements as well as a prey animal would, nor do they have the ability to perceive quick movements that a pure predator needs.

    • In fact, they can get along quite well as long as they stay out of each other's way.

      Good vision might help there.
    • The article mentions proto-primates, not what we would call primates today. So for those snakes and mammals, they might have had a stronger predator/prey relationship than what we call primates. The current relationship you bring up may be a result of primate evolution to be able to detect snakes better.

      I'm not arguing the theory is correct, just that it is self-consistent and sounds plausible.
  • by CurtMonash (986884) on Monday July 24, 2006 @09:35AM (#15769081) Homepage
    I've misplaced the link, if I ever had it (I just recall hearing about this from my wife the evolutionary biology teaching fellow) but there's currently a species of primate (bonobo?) that has different behaviors for different kinds of predators. They scurry up into trees for land-based predators, they go down under cover for large birds, and do something in between (I forget what) for snakes.

    And they have different calls for each of these kinds of predator.

    Well, they've developed another one for humans with rifles. And they give the call if they just see hunting dogs.

    So yeah -- adapting to predators is a top-level priority. Although in that case they're benefitting from previously-evolved capabilities, presumably, given the speed of adaptation.

  • COBRA!! (Cobra!)
    COBRA!! (Cobra!)
    Armies of the night
    Evil taking flight
    COBRA!! (Cobra!)
    COBRA!! (Cobra!)
    No where to run
    No where to hide
    Panic spreading far and wide
    Who can turn the tide?

    GI Joe- (A real American hero)
    Yo Joe!
    GI Joe is there
    Fighting for freedom
    Wherever there's trouble
    over land and sea and air
    GI Joe is there
  • I think I remember from psychology class, that an innate fear of snakes is one of the very few visible human instincts. It's also something that is present in all (or nearly all?) mammals? If you take a stiff rope and shove it towards a kitten (who has never dealt witha real snake before), he will have a far stronger reaction than with other toys. The recognition and fear of snakes is built-in. (Sorry I don't have any references offhand, just my hazy recollection; any expert care to commment?)
  • by lbmouse (473316) on Monday July 24, 2006 @10:07AM (#15769312) Homepage
    The only thing stranger than the content of this article is the fact that it is being hosted on foxnews.com.
  • Hmmm......and I'm afraid of Snakes.

    Coincidence?
  • I can't believe this. It feels like some one making a (bad) bid for funding rather than a realistic theory. The biggest problem I can see is that snakes don't eat humans, in fact snakes seem to pretty much go out of their way to avoid humans most of the time. Perhaps some of the very small primates are prey for snakes and as such their evolution would be partially guided by snakes. Humans evolved from fairly large primates; primates that are far to large for even a large snake to swallow. Ergo a snake woul

  • Fear of Samuel L. Jackson may drive post-human evolution it seems then?
  • Fox News Reports (Score:3, Interesting)

    by jeffsenter (95083) on Monday July 24, 2006 @10:37AM (#15769514) Homepage
    Folks this is coming from Fox News' science department. I wasn't aware Fox News had a science department and after reading the story I am still unaware of any reporting on science by Fox News.

    Snakes being a major force in the evolution of mammals including humans? I want to see some pretty strong evidence first.
  • by digitaldc (879047) * on Monday July 24, 2006 @10:50AM (#15769606)
    From: http://www.janegoodall.org/chimp_central/chimpanze es/behavior/rain_dance.asp [janegoodall.org]

    An excellent example of a respect and intense curiosity of chimpanzees to an animate object is in their reaction to snakes, particularly pythons. Pythons could pose a threat to young chimpanzees, but it is not likely that any snake would take on an adult. However, when a single individual or group of chimpanzees encounters a python (even a small one), the reaction is remarkable. One would expect the chimps to issue alarm calls to warn others and as an expression of their fear, but then to move well out of harms way as soon as possible. Predictably, the chimpanzees do issue a specific vocalization called a snake wraa, but when it is uttered, the group often draws near, to stare at the snake. Some climb above if possible for a better look. Typical facial expressions are those of fear and curiosity. Physical reassurance contact is often made (especially mutual embracing), and eye contact among individuals is frequent. After tens of minutes, members finally begin to disperse. Some individuals however, (Skosha and Apollo, for instance) show exaggerated and prolonged interest. Both call time and again even after the other individuals have moved well away. I have seen both stay and stare and call for as long as 30 minutes.
    It is difficult to explain why chimpanzees react to pythons in this way. It appears to be much more than keeping a close eye on a possible threat, as many species do. It also seems a great waste of energy and time. If pythons are dangerous, it would make much more sense to alarm call and move away as quickly as possible.
  • by Bryansix (761547) on Monday July 24, 2006 @11:06AM (#15769715) Homepage
    Indiana Jones: Snakes. Why'd it have to be snakes?
    Sallah: Asps. Very dangerous. You go first.
  • Snakes on Staff (Score:4, Insightful)

    by Doc Ruby (173196) on Monday July 24, 2006 @11:39AM (#15769984) Homepage Journal
    How come snakes are the ancient symbol for medicine [wikipedia.org] that we still use?
  • by tetranz (446973) on Monday July 24, 2006 @12:33PM (#15770425)
    Someone told me this long ago ... I don't know if its true but ...

    Someone in the Pacific during WWII made a lot of money by having a snake in a big glass bowl or something. He would get someone to hold their hand on the outside of the glass and then make a bet with them that they couldn't kept their hand there while the snake attacked them (safely) from the inside of the glass. I guess the rules were that they had to keep their eyes open and looking at the snake. He very seldom, if ever, lost the bet. Everyone, no matter how big and tough or unafraid of snakes they were, would involuntarily pull their hand away suggesting some sort of inbuilt fear of snakes.

Every nonzero finite dimensional inner product space has an orthonormal basis. It makes sense, when you don't think about it.

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