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Shark 6th Sense Related to Human Evolution? 308

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.'"
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Shark 6th Sense Related to Human Evolution?

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  • by art6217 ( 757847 ) on Wednesday February 08, 2006 @10:27AM (#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.
  • by Ancient_Hacker ( 751168 ) on Wednesday February 08, 2006 @10:34AM (#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.
  • by Ironsides ( 739422 ) on Wednesday February 08, 2006 @10:49AM (#14669315) Homepage Journal
    Having done this, there are a few different things that can cause this. Usually, you can feal the radiated heat coming off the person that is near you. Other than that, there is also the air movements that your skin is picking up. This has been done as a scientific experiment before, chalenging blindfolded people to stop as close as they can before walking into a wall. Next time you try this, try wearing a bandana. It confuses the skin sensors and you won't be able to do this.
  • Re:I don't get it. (Score:5, Interesting)

    by Mr. Underbridge ( 666784 ) on Wednesday February 08, 2006 @10:50AM (#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.

  • Neural crest cells (Score:5, Interesting)

    by Graham Clark ( 11925 ) on Wednesday February 08, 2006 @10:55AM (#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.
  • by Kesh ( 65890 ) on Wednesday February 08, 2006 @11:13AM (#14669488)
    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 it.

    * EM is caused by the movement of electrons. The one exception to us being unable to feel it is lightning. And I really don't think it matters at that point, do you? ;)
  • Re:I don't get it. (Score:5, Interesting)

    by InternationalCow ( 681980 ) <mauricevansteensel@nosPAM.mac.com> on Wednesday February 08, 2006 @11:23AM (#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.
  • Re:I don't get it. (Score:3, Interesting)

    by c_forq ( 924234 ) <forquerc+slash@gmail.com> on Wednesday February 08, 2006 @11:30AM (#14669600)
    "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 drastically different purposes might it not be a better hypotheses that different species use the same mechanisms due to the unique properties rather than assume a shared ancestor?
  • by ianscot ( 591483 ) on Wednesday February 08, 2006 @11:36AM (#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?)

  • by skids ( 119237 ) on Wednesday February 08, 2006 @12:12PM (#14669921) Homepage

    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"

  • Re:I don't get it. (Score:3, Interesting)

    by the_real_bto ( 908101 ) on Wednesday February 08, 2006 @12:13PM (#14669931)
    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 fit preconceived ideas, instead of just opening their mind and searching for the truth. To me that is what science is about or should be anyway, a search for the truth without prejudice.

    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.

  • Re:I don't get it. (Score:3, Interesting)

    by thatguywhoiam ( 524290 ) on Wednesday February 08, 2006 @03:35PM (#14671886)
    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 encompassing the systematic study of the structure and behavior of the physical and natural world through observation and experiment". The very definition of science requires that you must be able to prove and test your statements, in the real world. Its the best 'truth' we've got. You are conflating faith and belief, which are not the same thing.

    You are right in this sense only: I am fairly intolerant of unprovable bullshit. Is it really dogmatic to hold your convictions in proportion to your evidence?

  • Re:I don't get it. (Score:3, Interesting)

    by johnnyb ( 4816 ) <jonathan@bartlettpublishing.com> on Wednesday February 08, 2006 @03:58PM (#14672102) Homepage
    "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 evolution could even have taken place.

    _Most_ of the variation that takes place is the result of Mendellian inheritance, which, by the way, was discovered by a creationist (who used it to argue _against_ transformism).

    The environment induces a large part of variance. Scott Gilbert [nih.gov] has written about many of these, include variance resulting from an animal sensing predatory animals in the environment, and specifically changing their morphology to account for it. The process of genetic assimilation will make these changes the default morphology even in absence of the predator after a certain number of generations.

    Likewise, microbes can change their genome in response to the environment. They can use transposons to activate latent genes [nih.gov], they can induce a highly regulated mutagenesis [pubmedcentral.gov] which produces almost entirely beneficial mutations [nih.gov].

    Natural selection explains almost nothing. All natural selection means is that dead things don't reproduce, and sick things don't reproduce well. This is a conservative, not a creative process. And random mutation has too big of a search space to do anything productive. Perhaps you should take a 21st century view of evolution [uchicago.edu] rather than the 1950's version of it you are looking at now.

    Please tell me what the evidence is that (a) everything shares a common ancestor, and that (b) random mutation + natural selection is sufficient for creating the diversity that exists today from that common ancestor. If you want to be really adventurous, you can also show how (c) life could have proceeded from non-life.

    Also, while we're at it, you could try showing how choice can arise through material mechanisms. If choice can't arise through material mechanisms, then either (a) choice as a real entity doesn't exist, or (b) a material view of origins is insufficient.

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