Stories
Slash Boxes
Comments
Search

News for nerds, stuff that matters

Slashdot Log In

Log In

Create Account  |  Retrieve Password

Shark 6th Sense Related to Human Evolution?

Posted by ScuttleMonkey on Wed Feb 08, 2006 09:10 AM
from the really-suave-looking-sharks dept.
Science News
An anonymous reader writes "Scientists at the University of Florida are claiming that certain genes found in sharks that give them their 'sixth sense' and allow them to detect electrical signals could also be responsible for the development of the head and facial features in humans. From the article: 'The researchers examined embryos of the lesser spotted catshark. Using molecular tests, they found two independent genetic markers of neural crest cells in the sharks' electroreceptors. Neural crest cells are embryonic cells that pinch off early in development to form a variety of structures. In humans, these cells contribute to the formation of facial bones and teeth, among other things.'"
+ -
story
This discussion has been archived. No new comments can be posted.
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.

Shark 6th Sense Related to Human Evolution? 50 Comments More /

 Full
 Abbreviated
 Hidden
More
Loading... please wait.

  • News flash: orthologous structures... (Score:3, Insightful)

    by Anonymous Coward on Wednesday February 08 2006, @09:15AM (#14669060)
    ...do different things in different organisms. This is not news. It is a study of cellular fate in two different biological contexts of distantly related organisms.
    • ...do different things in different organisms. This is not news. It is a study of cellular fate in two different biological contexts of distantly related organisms.

      Oh, piss off. With that attitude there's no point in doing science at all. It's news to discover the genes and the mechanism and also to find out what structure it was that developed into the organ in question.

  • Wait a minute... (Score:4, Funny)

    by LilGuy (150110) on Wednesday February 08 2006, @09:16AM (#14669067)
    Which of these cells pinch off to form friggen laser beams?

  • How many senses do we have? (Score:3, Insightful)

    by SoupIsGoodFood_42 (521389) on Wednesday February 08 2006, @09:18AM (#14669079) Homepage
    It seems we get a new "sixth sense" every few months. Perhaps it's time to review the whole "five senses" thing so that people stop using "sixth sense" as if it's something special or supernatural?

    • Re:How many senses do we have? (Score:5, Informative)

      by Peter Mork (951443) <Peter.Mork@gmail.com> on Wednesday February 08 2006, @09:25AM (#14669137) Homepage
      Let's see, humans have: sight, sound, smell, taste, touch, pressure, deep pain, surface pain, referred pain, hot, cold, static equilibrium, and dynamic equilibrium. Some might even throw in thirst and hunger.

    • Re:How many senses do we have? (Score:5, Insightful)

      by pomakis (323200) <pomakis@pobox.com> on Wednesday February 08 2006, @09:40AM (#14669253) Homepage
      It seems we get a new "sixth sense" every few months. Perhaps it's time to review the whole "five senses" thing so that people stop using "sixth sense" as if it's something special or supernatural?

      The five senses that humans have are classified as such because they are five distinct ways that we can sense our environment and surroundings. (Some even argue that smell and taste are the same sense because they're both a chemical composition sense.) The ability to sense electrical signals is in every way, shape and form a distinct sense from the five that humans have.

      The universe allows only so many senses, because there are only so many ways that one object can make itself "known" to another object (which is exactly what senses are about). Think about it... there's radiation in the electromagnetic spectrum (sight), compression waves (sound), chemical traces (smell and taste), and actual contact (touch). But nature has a few other communication tricks up its sleeve, and electical signals is one of them. The fact that humans can't sense them doesn't mean that it's supernatural.


      • Personally I think balance is pretty darn distinct from the oft-quoted 5. For lay people that don't want to get into all the details (http://www.sirinet.net/~jgjohnso/senses.html [sirinet.net]) balance
        would be the obvious candidate for a popularly recognized "sixth sense"

        • Scientifically speaking, he's right. We detect one thing when something else hits our bodies. Whether it's a chemical (as in taste), a photon (for sight), or a physical object (for touch), something has to hit us for us to know it's there.

          And there's only so many things that can do that. Electromagnetic fields are one thing that hit us daily and we really don't even know it*, but sharks apparently can. No matter what, there has to be some sort of particle or wave there to actually hit us before we can sense
              • "The other 'objective' senses that you mentioned are just special subsets of the general senses. "

                Total bullshit. You're just saying that to give youself some kind of reason to cling to the outdated 'five senses'. Let's go through them:

                "Temperature sense - touch; "

                Wrong. Our pressure-sensitive nerve are totally seperate from our temperature sensing nerves. Different sense altogether.

                "CO2 sense - smell/taste;"

                Tell me, what does CO2 smell/taste like?

                "humidity sense - smell/taste and possibly touch;
    • Erm, this is one sharks have and we don't - they can sense electrical activity in the water. It is one of only six senses we currently count sharks as having, and the other five are identical to human ones.

  • wtf (Score:3, Funny)

    by bermudatriangleoflov (951747) on Wednesday February 08 2006, @09:18AM (#14669082)
    So this is why I was born with a dorsal fin
  • http://www.signonsandiego.com/uniontrib/20060104/n ews_1c04narwhal.html [signonsandiego.com]

    maybe our teeth can pick up radio stations someday :)

  • No mammals? (Score:5, Informative)

    by Jordan Catalano (915885) on Wednesday February 08 2006, @09:21AM (#14669104) Homepage
    As they evolved, mammals, reptiles, birds and most fish lost the ability. Today, only sharks and a few other marine species, such as sturgeons and lampreys, can sense electricity.

    The platypus [wikipedia.org] begs to differ...

  • heh (Score:5, Funny)

    by Moby Cock (771358) on Wednesday February 08 2006, @09:24AM (#14669126) Homepage
    A shark's 6th sense.

    "I see soon-to-be dead people"

  • You mispelled... (Score:5, Funny)

    by Anonymous Coward on Wednesday February 08 2006, @09:24AM (#14669131)
    The researchers examined embryos of the lesser spotted catshark.

    You misspelled laser.

  • People have 6th sense, too (Score:5, Interesting)

    by art6217 (757847) on Wednesday February 08 2006, @09:27AM (#14669157)
    Have you ever, while having your eyes closed, felt the position of a pointy object several contimeters distant from you face, especially from your forearm? I did and many people know that feeling. I have no idea whether this is an electrostatic field or what, or if it has anything common with... sharks, but it is probably quite a common phenomenon. I do not really know why I have not seen it described anywhere in the literature.

  • That missing link... (Score:3, Funny)

    by Tominva1045 (587712) on Wednesday February 08 2006, @09:28AM (#14669165)


    In a directly related story, scientists have found THE missing link between sharks and humans in a sub-species. They are calling it entrepreneurius-maximus.

    Offer not valid in NY, Conn., CA, MA, etc.

  • most fish can sense electricity (Score:3, Insightful)

    by peter303 (12292) on Wednesday February 08 2006, @09:33AM (#14669207)
    Most fish have some electrical sense, though some may do it better than others. I'd guess this sense was re-invented many times.

    Terrestial animals, including humans, can feel strong gradients in the air before thunderstorms.

  • Humans already have a 6th, 7th, 8th senses. (Score:4, Interesting)

    by Ancient_Hacker (751168) on Wednesday February 08 2006, @09:34AM (#14669214)
    6th sense: Your "stuffy room" sensor for excess CO2. 7th sense: Infrared sensors around your lips: Close your eyes. Put your hand three inches from your face. Feel the heat around your lips? 8th sense: Your ears can correlate pressure changes to detect that you're between walls.

  • Good news for Creationists (Score:4, Funny)

    by WormholeFiend (674934) on Wednesday February 08 2006, @09:44AM (#14669273)
    They'll be happy to know that they haven't evolved from monkeys after all!

  • Neural crest cells (Score:5, Interesting)

    by Graham Clark (11925) on Wednesday February 08 2006, @09:55AM (#14669363)
    There's a saying in developmental biology circles that neural crest [wikipedia.org] cells are the only really interestng part of vertebrate embryology. They form (IIRC) the autonomic nervous system, endocrine glands and pigment-producing cells too, as well as the ganglion of the auditory nerve - which is why some animals show a link between colouration and deafness.

  • not much here (Score:5, Informative)

    by tgibbs (83782) on Wednesday February 08 2006, @10:35AM (#14669640)
    If I were asked to guess what embryonic tissue shark's electroreceptors came from, my first guess would be neural crest. After all, this is the tissue that gives rise to electrically active tissues like nerve and muscle, which have receptors that do indeed "sense" electrical fields. This is not to allow the animal to sense electrical fields in its environment, but simply the way nerve conduction and muscle contraction work--a change in electrical field (typically produced by a chemically activated ion gate in a membrane) is "sensed" by a voltage-gated ion channel that responds by opening up additional channels, further altering the electric field, which stimulates other voltage-gated ion channels, and so forth. It is easy to see how such a process could be evolutionarily adapted for sensory purposes, just as fish that generate strong electric fields, such as Torpedo (the electric ray) do so with tissues that are evolutionarily derived from muscle.

    So basically, all this is saying is that we and sharks have a common ancestor and as a result share similarities in the development of nervous tissue (which we knew already), and that sharks' electro receptors develop from the tissue that any biologist would identify as the "usual suspect."

  • The other way -- humans "feeling" a shark (Score:5, Interesting)

    by ianscot (591483) on Wednesday February 08 2006, @10:36AM (#14669650)
    This headline hit me the wrong way. On Saturday I take the kids on a week-long Hawaii trip, and we've been following a little series of white shark sightings near the islands. It seems like some of the big female whites are out there -- a shark tour guy got out and swam with a "sisterhood"-scale 20-footer whose girth was astonishing in the pictures.

    Anyway, one of the hard-to-pin-down aspects of shark encounters is a "sense" people report having just before they become fully aware of a big shark's presence. This may just be memory colored by the adrenaline rush that came with the encounter -- but it's very commonly reported that, moments before the water starts boiling or whatever, the surfer gets a cold, "something isn't right here" feeling.

    (Which would also be a touch of an evolutionary advantage for the person able to sense it, yeah?)

    • Common (backboned) ancestor with (they think possibly) an electro-whatever sense

    • Re:I don't get it. (Score:5, Funny)

      by ackthpt (218170) * on Wednesday February 08 2006, @09:49AM (#14669316) Homepage Journal
      Is it implying that we desended from a common ancestor or that we descended from sharks with this ability?

      Yes, the single-cell southeastern australian wombat.

      I don't think that's very plausible. After all, humans claim to have ESP and what's that supposed to be? Detection of electrical impulses from just into the future?

      'sixth sense' and allow them to detect electrical signals could also be responsible for the development of the head and facial features in humans.

      Actually, I saw Sixth Sense and what it really allows sharks to do is see the ghosts of dead sea-life which lead them to the carcasses. Shit, I thought everyone already knew that.

    • Re:I don't get it. (Score:5, Interesting)

      by InternationalCow (681980) <mauricevansteensel AT mac DOT com> on Wednesday February 08 2006, @10:23AM (#14669548) Journal
      It just implies that sharks and us, remotely related as we are, use a common toolkit to specify seemingly different kinds of things, such as electroreceptors and neural crest cells in humans. The former may be neural crest derived. So are many receptors in our skin. It does not mean that we are descended from sharks in any way. We are related, as all life is. Nature abounds with examples where very remotely related genera will use very similar genes to specify tissues with similar functions but very dissimilar compositions. The same gene that specifies eyes in the fruit fly for instance specifies eyes in us humans. Yet our eyes are not like those of a fly at all. The gene says "Make an eye here". The same will apply to electroreceptors in sharks and neural crest derivatives in humans. One of the genes might say "migrate here and make this receptor", regardless of the identity of the receptor. A gene is a tool, like a hammer. It is not the blueprint.
            • Look up the recent publications about alcohol dehydrogenases. What you now mention is a good example of convergent evolution, where the needs of function impose structure. The argument you use to counter my reply in effect proves my point. If you are a believer in intelligent design, please admit to it. But do not bother us here with its flawed arguments. For further discussion everybody is better off reading the judge's dissection of intelligent design in the recent Kansas ruling.

      • Re:I don't get it. (Score:5, Interesting)

        by Mr. Underbridge (666784) on Wednesday February 08 2006, @09:50AM (#14669328)
        I don't understand why the evolutionists always use new, would-be completely neutral discoveries to try and push their agenda.

        "Evolutionists" don't have an agenda, unless you count science as an "agenda." We don't consider science to be subject to public policy, and as such, laymen don't get a vote.

        This has absolutely nothing to do with evolution

        If you believe in the general concept of "science" it absolutely does.

        My point isn't to try and start a flame war, just simply that it's poor journalism to take something completely irrelevant to origin of life

        Read the damned article. They're talking about the same stem cells in the embryo developing into electrosensors in sharks and ears in humans. That absolutely has everything to do with embryonic development which is known to mirror vertebrate evolution, at least to those who follow science.

        It makes for bad science.

        Are you a scientist? Because among actual scientists, evolution is as much an established fact as gravity. Don't fall off the edge of the flat earth on your way out the door.

        • "Evolutionists" don't have an agenda, unless you count science as an "agenda."

          I'm going to have to disagree slightly here. There are evolutionists, and they do have an agenda. There are also scientists, most of whom believe in evolution. I think the line can be drawn when people make statements as facts, like in GP pointed out that the author of the summary did, instead of stating the simplest hypotheses which has not been disproved by any observational evidence. Since we use these same mechanics for
          • I agree. To generalize a bit and throw in some random thoughts, the word dogma comes to mind when I read many posts about science on Slashdot. Here is a definition of dogma from Wikipedia:

            "Dogma is belief or doctrine held by a religion or any kind of organization to be authoritative and not to be disputed or doubted."

            In my estimation that definition describes a lot of Slashdotters' beliefs in science and scientists. Similar to what the author of the summary wrote. People are looking for ammunition to fi
            • I'm a bit off topic here and rambling, I guess seeing people try to bend and form scientific research to prove their own belief systems has been disturbing me lately. It seems that science is the new religion for many. This new religion's adherents are just as intolerant of other's viewpoints as good old fashioned religions have been.

              Oh, you were doing so well until that last bit...

              Science cannot become 'the new religion for many', intrinsically. Science is "the intellectual and practical activity enco

            • "Shared genetic material, shared aspects of biochemistry that could be different, shared morphology, etc."

              Aren't those the same kinds of similarities between cars that have vastly different designers and designs? You're not proposing that cars are not the product of separate creations just because they have a lot of similarities are you?
                • "Aren't you actually grossly violating that by attempting to bring forth an untruth because you're too lazy to check the evidence?"

                  I have checked the evidence.

                  "Evolution and natural selection is the cause of most, if not all, variation in the biological world."

                  This is simply false. Natural selection has not been able to explain hardly anything. It is simply invoked. Read some biological papers. Whenever something new is found, it is simply listed as "having evolved" without any discussion about how the
              • I have no idea what you mean by "Laws of life on earth", and the "could be different" is critical. The morphology doesn't aid your point, as it isn't anywhere near "right", and there's developmental stuff.

                Seriously: When it comes to shared ancestry, the evidence is very, very, very strong. There are hundreds of thousands of datapoints. There are an extreme number of predictions that have been done based on this, there are extreme amounts of verification.

                You are actually jumping to a conclusion. I'm

          • Let us just say that the preponderance of evidence supports the theorey of evolution. Something that can not be said for creationism as explianed in the bible.

            You are right, of course, bad science is everywhere you look. There will be scientists who believe in creationism, even blindly so. Afterall, we are all inherently irrational creatures and scientists are no exception.

            Science, on the other hand, strives for the most rational explanations. And when the Grandparent said: We don't consider science

          • (A) Behe's books has repeatedly been debunked.
            (B) The claim of "many" is overblown. There are a very very few, compared to the overall number of people that study this. Almost all of them have the distinction of being a member of some religion that have their belief. And few of them seem to even be against evolution per se - they just try to insert other factors *too*, for instance saying "There is evolution BUT specication comes from God". And there is no significant rationale for doing so.

            WRT "trea

    • Re:Definition of Science (Score:4, Insightful)

      by 49152 (690909) on Wednesday February 08 2006, @09:37AM (#14669232)
      The scientific method is pretty much the definition of how you aquire science (systematic knowledge). To agree or disagree with a definition does not make much sense.

      However even if a model or theory cannot be scientificly proven or disproven it might be of use anyway, for example: mathematics is in fact not a science since it is derived from axioms (fundamental concepts *belived* to be true). Even so, no scientist would deny the usefulness of mathematics ;-)

    • BTW... (Score:5, Informative)

      by Black Parrot (19622) * on Wednesday February 08 2006, @10:13AM (#14669487)
      > I disagree that science is restricted to that which can be demonstrated using the scientific method. Humans have been engaging in scientific inquiries for millenia, yet the scientific method is a recent invention. The scientific method facilitates the acquisition of scientific knowledge, but it is not the only possibility. There are times when performing a scientific experiment is impossible or immoral. In these cases, we can still make observations and construct models, even though we cannot directly test those models.

      It sounds like you're saying that "the scientific method" = "laboratory experimentation". If so, that's not correct. Astronomy, for example, uses the scientific method.

      Also, "directly test" is a pretty slippery concept. Arguably nothing is direct, e.g. when we weigh a compound we are getting its weight indirectly (through whatever mechanism the scale uses), and we only see the output via the photons that our retina catches.

    • Re:6th sense (Score:5, Insightful)

      by meringuoid (568297) on Wednesday February 08 2006, @10:47AM (#14669721)
      Look, this whole 5 senses thing goes back to Aristotle. He was just trying to find some order in a chaotic world. So the dude was wrong. Give him a break, he's dead, ok?

      Yeah. He was wrong. That's OK. Trouble is, he was wrong about just about every single thing he tried, and then got cited as an unassailable authority by just about everyone in Europe for over a thousand years.

    • Common elements of humans found in rocks. Have we evolved from a common ancestor?

      Do rocks regularly make imperfect, self-sustaining copies of themselves?

      If not, then your analogy is completely and totally inane.

All trademarks and copyrights on this page are owned by their respective owners. Comments are owned by the Poster. The Rest © 1997-2009 Geeknet, Inc.