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Medicine Science

Scientists Wonder What Fingerprints Are For 347

Posted by kdawson
from the whorls-and-ridges dept.
Hugh Pickens writes "The BBC reports that scientists say they have disproved the theory that fingerprints improve grip by increasing friction between people's fingers and the surface they are holding. Dr Roland Ennos designed a machine which enabled him to measure the amount of friction generated by a fingerprint when it was in contact with an acrylic glass at varying levels of pressure. The results showed that friction levels increased by a much smaller amount than had been anticipated, debunking the hypothesis that fingerprints provide an improved grip. Ennos believes that fingerprints may have evolved to grip onto rough surfaces, like tree bark; the ridges may allow our skin to stretch and deform more easily, protecting it from damage; or they may allow water trapped between our finger pads and the surface to drain away and improve surface contact in wet conditions. Other researchers have suggested that the ridges could increase our fingerpads' touch sensitivity."
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Scientists Wonder What Fingerprints Are For

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  • by Karganeth (1017580) on Sunday June 14, 2009 @07:26AM (#28325881)
    If it takes an equal amount of resources for the body to grow a finger without fingerprints then it makes sense that they not meant for anything. Not everything has to have a purpose.
  • Yup. (Score:3, Insightful)

    by El Jynx (548908) on Sunday June 14, 2009 @07:26AM (#28325885)

    Sounds about right. Such micro-ridges, I think, WOULD increase grip on rougher surfaces, which is what we would run into in daily life. Also, if those ridges - generally the top layer of skin - would rip off or shred, the damage done to the hand would be less than were it smooth, I would guess. IOW, maybe a safety feature?

  • Unlikely. (Score:3, Insightful)

    by El Jynx (548908) on Sunday June 14, 2009 @07:29AM (#28325891)

    It's more likely for something used this much to have functional features than not. Fingers and claws have been around for quite a while. It's hard to imagine them not evolving useful properties. Of course, this can go too far. Try peeling a gecko from a wall, you need to call the Hulk to help.

  • by malchus842 (741252) <stephen@adamsemail.net> on Sunday June 14, 2009 @07:33AM (#28325909) Homepage

    Throughout history, there have been lots of questions that science has not been able to answer. But science is not static. Over time, it has been able to answer more and more questions and close more and more of the 'gaps.'

    For any theist, the 'God of the Gaps' defense is pretty weak. Just because we don't understand something doesn't require a God (or gods) to explain it.

    This is not a rejection of theism, but simply a comment on science - just because we don't have an answer now doesn't mean we won't have an answer in the future. And not having an answer does not imply that there is a (or many) God(s).

  • Re:Primates (Score:3, Insightful)

    by Anonymous Coward on Sunday June 14, 2009 @07:36AM (#28325919)

    There are probably multiple reasons for the fingerprints.

    The skin has to be both flexible and durable at the same time, and gripping on moist surfaces should also be safe.

    A flexible skin is also allowing for better dexterity and a finer resolution when sensing surfaces.

  • it's hard... (Score:0, Insightful)

    by Anonymous Coward on Sunday June 14, 2009 @07:49AM (#28325961)
    ...to suppress the knowledge of a designer, particularly with such a stupid idea as evolution!
  • by TREE (9562) * on Sunday June 14, 2009 @07:51AM (#28325971)

    Maybe they work like treads on car tires... let there be someplace for liquids to move *away* from to improve grip. Or, maybe having "with oil" and "without oil" surfaces that can be selected by varying grip allows gripping different types of surfaces.

    Also, grip isn't the only thing hands do. Wiping or scrubbing with your fingers requires some level of abrasiveness.

    I suspect that there may be a connection between building calluses and having prints. Possibly, prints are just the way we make "tough" skin that is more resistant to injury.

  • by koolfy (1213316) <koolfy.gmail@com> on Sunday June 14, 2009 @07:58AM (#28325997) Homepage Journal
    If fingerprints had no value (to survive/reproduce) in any way, species with and without fingerprints would be equal in the natural selection.
    That would imply that when a monkey would be born without those (genetic mutation somewhere), there would be no reason for him to be less likely to survive and reproduce than his peers having fingerprints, and when he would procreate, it would create a variation of those monkeys having no fingerprints.

    If we have fingerprints, it's genetically possible to be born without, so it's very likely that that mutation existed in the history of evolution, and that one of those specimen procreated, creating that fingerprint-less type of monkey/man.

    My point is : if it's likely to have happened that way, the only reason not to have any fingerprint-less man or monkey on earth, is that at one moment in evolution, fingerprints gave an advantage to increase the survival and reproduction rate over the other alternatives.

    I may be wrong, but that's how I understood the Darwinian model in science class...
  • Many things (Score:5, Insightful)

    by bytesex (112972) on Sunday June 14, 2009 @08:13AM (#28326063) Homepage

    More grip, larger surface, which means more flexibility, more nerve-endings - more sensitivity, better warmth-exchange, 'folded-up-ness', which means more protection from wounds, easier to clean (like footprints, the mud just falls out), 'little bits that stick out' - meaning more sensitivity again.

  • by YourExperiment (1081089) on Sunday June 14, 2009 @08:15AM (#28326075)

    With articles such as this, it's hard to tell whether we're being subjected to bad science or bad journalism. Both the summary and TFA quite categorically state that the "myth" of fingerprints being used to improve grip has been disproven. They then go on to describe how this experiment tested whether fingerprints helped when grasping an extremely smooth surface, and found out that they didn't (well okay, actually they did, but not by very much).

    Finally, some alternate hypotheses as to why fingerprints evolved are posited, the first of which is: they may improve grip on rough surfaces. Not acrylic glass or anything, but those other kind of surfaces - you know, the type that actually occur in nature.

    I'm pretty sure I don't know much more now than I did before I read the article.

  • by maxume (22995) on Sunday June 14, 2009 @08:50AM (#28326221)

    Or a population of primates that happened to have fingerprints became dominant for some other reason.

    It is often the case that an environmental shift makes an existing trait advantageous (that trait may have been meaningless in the previous environment), rather than an advantageous trait arising in a static environment.

  • by funkatron (912521) on Sunday June 14, 2009 @08:53AM (#28326243)

    If we have fingerprints, it's genetically possible to be born without, so it's very likely that that mutation existed in the history of evolution, and that one of those specimen procreated, creating that fingerprint-less type of monkey/man.

    I would actually question to what extent this is a possibility. Human skin has all sorts of textures and patterns, most of which we don't treat with any significance. It may be that smooth skin is actually difficult to produce by biological processes. This is a possibility that should at least be considered.

  • Re:Primates (Score:3, Insightful)

    by Devout_IPUite (1284636) on Sunday June 14, 2009 @08:56AM (#28326261)

    Most mutations that get kept are somehow beneficial. Not all, but most.

  • Re:Primates (Score:2, Insightful)

    by bluesatin (1350681) on Sunday June 14, 2009 @08:57AM (#28326275)
    Well the main route for evolution to occur (survival of the fittest) is pretty much dead.
  • by jonbryce (703250) on Sunday June 14, 2009 @10:00AM (#28326573) Homepage

    Aetheism is a religion.

  • Re:Primates (Score:5, Insightful)

    by stonewallred (1465497) on Sunday June 14, 2009 @10:18AM (#28326643)
    most evolutionary features get kept that do not kill the person/animal having it, and which does not put it at a disadvantage in reproducing. There are many more evolved features that do nothing that have been kept than you think.
  • Re:Primates (Score:2, Insightful)

    by Hal_Porter (817932) on Sunday June 14, 2009 @10:34AM (#28326735)

    I don't see why them being unique is so surprising. Faces are unique after all. All of us have a unique genome, apart from identical twins. Still even twins have different fingerprints and hair follicles and so on are in different places. I guess when embryos develop the process for skin folding and hair follicle development is slightly random - i.e. the genes encode the probability of a fair follicle, not its exact location.

  • by jonbryce (703250) on Sunday June 14, 2009 @10:36AM (#28326743) Homepage

    "I believe there is no God" is as much a statement of faith as "There is no God but Allah, Muhammad is his messenger". There is no scientific evidence to prove or disprove either statement.

  • Re:Primates (Score:5, Insightful)

    by Reziac (43301) * on Sunday June 14, 2009 @11:02AM (#28326881) Homepage Journal

    Exactly -- why does it have to be for any particular use? More likely it's just an artifact of how skin develops. People forget that many traits didn't evolve for a specific purpose, but rather, were random mutations that were not selected against, becauee they did the species no harm.

    The whole question also shows a profound ignorance of the rest of the animal kingdom:

    Dogs have noseprints that are as unique as fingerprints (and in fact are legal ID for dogs in Canada). Why is this? Probably no reason at all, other than quirks of individual cell layout in the skin layer.

    Chickens have similar uniqueness in the surface of their combs. Why? Likewise, probably no reason, other than it's just a trivial quirk of how the skin cells piled up in a given individual.

  • by Fribulator (1001425) on Sunday June 14, 2009 @11:28AM (#28327097)
    Although that seems like a good idea at first, if the treatment was powerful enough to remove his fingerprints, it could have caused some nerve damage as well, which could cause his diminished sensitivity. However, if he (and other such people) were to submit to tests and scans and general research, they would surely prove helpful in deciphering the mystery of the fingerprint.
  • by Anonymous Coward on Sunday June 14, 2009 @12:10PM (#28327363)

    "I believe there is no God" is as much a statement of faith as "There is no God but Allah, Muhammad is his messenger". There is no scientific evidence to prove or disprove either statement.

    "I believe there is no Easter Bunny" is as much a statement of faith as "There is no Easter Bunny but Frank". There is no scientific evidence to prove or disprove either statement.

  • by samuraiz (1026486) on Sunday June 14, 2009 @12:14PM (#28327385)

    Can you honestly not see how asserting a positive without evidence is different from asserting a negative based on lack of evidence?

    Hint: in the former case, like in your Allah example, one is ascribing specific properties to something that is unobservable, impossible to test, impossible to prove. There is another word for this: fantasy.

    There is no scientific evidence for unicorns, but I believe they're out there anyway because I want to/an old book told me to think that/it's convenient to my laziness of intellect.

  • Re:Primates (Score:3, Insightful)

    by amicusNYCL (1538833) on Sunday June 14, 2009 @12:37PM (#28327517)

    Thank you, I'm glad this is the first post listed.

    Dr Roland Ennos designed a machine which enabled him to measure the amount of friction generated by a fingerprint when it was in contact with an acrylic glass at varying levels of pressure. The results showed that friction levels increased by a much smaller amount than had been anticipated, debunking the hypothesis that fingerprints provide an improved grip.

    That's totally BS science. That disproves the hypothesis that fingerprints provide improved grip on acrylic glass, not that fingerprints provide improved grip on other surfaces.

  • by Anonymous Coward on Sunday June 14, 2009 @01:01PM (#28327673)

    No it's not. Atheism is a belief: a belief in there not being a god.

    Belief is not religion.

    The statement "I believe in little green men" is not a religious statement. Neither is the statement "I don't believe in little green men."

    So why should a belief in no god be a religious statement? By your logic, very few things are not religions.

  • by Planesdragon (210349) <slashdot@@@castlesteelstone...us> on Sunday June 14, 2009 @01:09PM (#28327707) Homepage Journal

    Carl Sagan had a graph of scientific progress - basically very rapid in Ancient Greece and zero in the Dark Ages

    Yeah. Articulated armor, steel long-swords, and crop rotation aren't science at all....

    And it sure wasn't religion that got all of the Greek city-states to stop fighting every four years and come together for the olympics. Nope. Not that, either.

    You're arguing from authority, and "noted atheist says religion is bad" is no more credible than "pope says modernism is bad."

  • Re:Primates (Score:3, Insightful)

    by Lord Ender (156273) on Sunday June 14, 2009 @01:10PM (#28327715) Homepage

    Why presume they have a function? Evolution weeds out costly features. If fingerprints have little cost, it is wrong to assume they necessarily exist to serve some specific purpose.

  • by jbengt (874751) on Sunday June 14, 2009 @01:31PM (#28327853)

    Carl Sagan had a graph of scientific progress - basically very rapid in Ancient Greece and zero in the Dark Ages. As Christianity lost its grip in Europe science picked up again.

    As if the plague had nothing to do with that. Or the breakdown of civility with the fall of the Roman Empire and rise of bands of knights in perpetual raids and gang wars for their lords.
    Anyway, there was a lot of progress on science and math during the Middle Ages in the Muslim middle east, which was not exactly a bastion of atheism.

  • Re:Primates (Score:4, Insightful)

    by Reziac (43301) * on Sunday June 14, 2009 @07:37PM (#28330495) Homepage Journal

    Dogs often use their noses like a jack-hammer... the nosepad is not particularly sensitive to touch. If your dog is too wiggly to get a noseprint (which one does with a paper-pad and roll-on ink, much as one would footprint a baby), chances are the dog needs more training, and you need lessons on how to be the pack leader, too.

    (Disclosure: I am a professional dog trainer. :)

  • by Anonymous Coward on Sunday June 14, 2009 @09:48PM (#28331239)

    And they also have lab techs performing interrogations, all of them seem to be happy with their hair in their face while they're searching for fibers on a mattress or gathering evidence from a crime scene.

Brain damage is all in your head. -- Karl Lehenbauer

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