Slashdot Mirror


Can Science Ever Be "Settled?"

StartsWithABang writes "From physics to biology, from health and medicine to environmental and climate science, you'll frequently hear claims that the science is settled. Meanwhile, those who disagree with the conclusions will clamor that science can never be 'settled,' and then the name-calling from 'alarmist' to 'denier' ensues. But can science legitimately ever be considered settled, and if so, what does that mean? We consider gravitation, evolution, the Big Bang, germ theory, and global warming in an effort to find out."

39 of 497 comments (clear)

  1. i interpret it to mean by Anonymous Coward · · Score: 5, Insightful

    all attempts to disprove it have failed and until evidence can be presented to disprove or bring the results into question it is settled

    it doesn't mean "this is doctrine never challenge it" it means challenge it knowing that it has been challenged before and the theory has held

    1. Re:i interpret it to mean by jellomizer · · Score: 4, Insightful

      A rare scientific law means it is settled.
      For most of them their are theories. the strength of the theory is based on the amount and quality of evidence for it, and lack of evidence that disproves it.

      The issues we are having isn't a problem with the science per-say. But people who religion/political stance is hindered by this science. So they will blame the people who came up with this conclusions as manipulating all their data to come to the conclusion.

      While they are situations where scientists manipulate their data to make their conclusion, however if the peer review is thorough it is usually disproved, or at least found to be not-reproducible.

      The biggest problem is the media posting confusing a hypothesis with a theory. So average joe who doesn't know the difference, see those scientists getting it wrong again!

      --
      If something is so important that you feel the need to post it on the internet... It probably isn't that important.
    2. Re: i interpret it to mean by Anonymous Coward · · Score: 5, Informative

      That isn't true. The term law was used in the past with the expectation that certain things were settled. The philosophical underpinnings of science have advanced since then and the term law is no longer used. Some older theories are still referred to as laws for historical purposes however they are theories. Theromes do exist but always with a defined set of starting axioms and therefore a theorome when applied to the physical world becomes a theory.

    3. Re: i interpret it to mean by Daniel+Dvorkin · · Score: 4, Informative

      Theromes do exist but always with a defined set of starting axioms and therefore a theorome when applied to the physical world becomes a theory.

      Theorems and theories are two different things. You're quite right, that proving a theorem requires a well-defined set of axioms; the natural world, unfortunately, doesn't provide us with such axioms*, which is why we have to use theories to describe it.

      *Well, maybe. "The unreasonable effectiveness of mathematics" argues that maybe there is some axiomatic Truth at the basis of reality. But if so, we have no idea what it is yet, and anyone who tells you they know is lying.

      --
      The correlation between ignorance of statistics and using "correlation is not causation" as an argument is close to 1.
    4. Re:i interpret it to mean by fahrbot-bot · · Score: 5, Funny

      A rare scientific law means it is settled. For most of them their are theories ...

      The problem most people have is confusing Scientific Theory and pundit "theory" (mind the quotes). The two are not the same -- I even question Commander Data's overuse of the word theory in his many musings. I think he was sometimes a little slack in his application, but that's just a theory.

      --
      It must have been something you assimilated. . . .
    5. Re:i interpret it to mean by riverat1 · · Score: 5, Insightful

      No, the use of the term "law" in science is an old usage that doesn't get applied much any more. Theory and law essentially have the same meaning in science, that is something with lots of evidence to back it up and little evidence to reject it. What hasn't been relatively "settled" is science is generally called a hypothesis.

    6. Re:i interpret it to mean by ClickOnThis · · Score: 5, Informative

      Laws have been settled and theories haven't.

      This is a common misconception. It appears in several places in this thread. I suffered myself from this misconception before someone set me straight.

      Roughly speaking, laws are quantitative whereas theories are conceptual. They both need experimental evidence to be considered "settled" in the sense of the current discussion, and both can be considered to have equal support in that sense. One is not "stronger" than the other.

      For example, Newton's laws of motion express relations between quantities measured of objects in motion. Atomic theory provides a conceptual framework for explaining the behaviour of matter. Both are highly successful. The latter is in no way reduced by calling it a theory.

      Feynman, in the first of his Lectures on Physics asked his reader to imagine that some cataclysmic event has wiped out all human knowledge, but that one single sentence could survive to be passed on to the next generation. What would he suggest that sentence be? The universe is made of atoms.

      --
      If it weren't for deadlines, nothing would be late.
    7. Re:i interpret it to mean by preaction · · Score: 4, Insightful

      The people who do that have conflated proof with faith. We absolutely should not have faith in science, we should demand proof. Science is Faith's eternal enemy!

    8. Re:i interpret it to mean by ShanghaiBill · · Score: 5, Interesting

      The best description of this is Isaac Asimov's essay The Relativity of Wrong. He points out, that while science is often wrong, as time goes on, the degree of wrongness diminishes. For instance, Einstein showed that Newton's laws of motion were wrong, but Newton was less wrong than Aristotle.

    9. Re:i interpret it to mean by i+kan+reed · · Score: 3, Interesting

      Now, "proof" is a dangerous word in science. It's vague, it's literally impossible to do in a truly strict sense within the scientific method, and people are quick to take the term to mean something it doesn't.

      Vagueness:
      It can mean anything from basic empirical evidence of a contentious event occurring(like proof that flies lay eggs) to a theoretical framework so soundly tested and retested as to lack detectible flaws(like the law of attraction).

      Impossibility:
      The philosophical or mathematical proof takes premises, and using absolute rules arrives at inescapable and undeniable conclusions. In a sense, this is possible with science: Assume an object is in motion at a certain velocity v. Assume it's position is x. Assume no force is applied. After t time, inescapably it's new position is x+v*t, by deduction. But science allows that to be wrong just as soon as someone comes forward with an experiment where it doesn't happen(though our first guess would be that one of the assumptions is untrue, given just how reliable laws of motion are). You can never have a proof that is just true.

      Quick to confusion:
      The various definitions here are easy for people to conflate or mistake. Just look at people expecting "proof" of evolution. They simultaneously want empirical evidence of a contentious hypothesis, like you'd test in a lab, and applying the concept to an entire branch of study, which has an entirely different idea of "proof". It all adds up to a scenario where people don't get what it is that they don't get.

      And they have very high expectations from pop culture: person in lab coat gets item, "aha we know what this is now that we've run 'tests'". They see science as much the same.

    10. Re:i interpret it to mean by butalearner · · Score: 3, Funny

      Feynman, in the first of his Lectures on Physics asked his reader to imagine that some cataclysmic event has wiped out all human knowledge, but that one single sentence could survive to be passed on to the next generation. What would he suggest that sentence be? The universe is made of atoms.

      Feynman is awesome, but that dude has a serious under-appreciation for abusively long run-on sentences filled with literary non sequiturs and mathematical and chemical formulae.

    11. Re:i interpret it to mean by flaming+error · · Score: 3, Insightful

      "These words have specific meanings"

      And all those words have multiple meanings.

      From the context it seems clear that OP was saying, but I'll attempt to clarify:

      1) the scientific method historically has proven a better vetter of hypotheses than believing really hard in religious orthodoxies' explanations of natural phenomena;

      2) the scientific method requiires rigorous and objective standards, and is incompatible with the subjective/feel-good/suspension-of-disbelief approaches believers take toward religion.

    12. Re:i interpret it to mean by Kazoo+the+Clown · · Score: 5, Interesting

      Yes, I like to use this relative wrongness to illustrate "what's wrong" with pseudoscience. Science advances when someone finds something wrong with current theory. You learn from your mistakes. So I ask you, when was the last time someone found an error in the theory of Astrology? Of Creationism? Of anti-AGW? If mistakes AREN'T being found in these "sciences" they aren't progressing. Instead, if they're finding mistakes it's not in their own theories, but in the competing theories, like Creationism finding errors in Evolution or anti-AGW in AGW. The funny thing about that is, to the extent they are actually finding legitimate errors (and not just misinterpreting, misrepresenting or misunderstanding), they are actually contributing to making their "opponents" science better.

    13. Re:i interpret it to mean by cmdr_klarg · · Score: 5, Insightful

      Science is Faith's eternal enemy!

      Science is not Faith's eternal enemy. Faith is Science's eternal enemy.

      Ignorance is Science's eternal enemy. Faith in and of itself is not Science's enemy, but it is not unusual for Faith and Ignorance to go hand in hand.

      --
      THE SOFTWARE, IT NO WORKY!!!
    14. Re:i interpret it to mean by Pino+Grigio · · Score: 4, Insightful

      Peer-reviewed publication is how scientists communicate with each other and keep track of errors

      Depends on the field. It would be better if papers were more readily retracted when wrong. And peer review itself is a kind of group-think that sets the bar very high for hypothesis that go against the paradigm and prevents publication, for very Human reasons, of contrary analysis and opinion. Peer review isn't in itself all that useful a process for science.

    15. Re:i interpret it to mean by david_thornley · · Score: 5, Insightful

      Make a stupid comment, get downmodded, is more like it. The "politically correct dogma" Slashdot is working on is that highly intelligent people who have studied something all their professional lives are likely to be closer to being correct than people who just don't get thermodynamics.

      --
      "When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes
    16. Re:i interpret it to mean by russotto · · Score: 3, Insightful

      How many actual scientific theories have been outright debunked. I don't count pseudoscientific bafflegab like phrenology or Ptolemaic cosmology as being science. I'm talking about out and out scientific theories posited under something approaching the methodological naturalism that evolved out of the Enlightenment.

      Phlogiston. The luminiferous ether, as you mentioned. Einstein's local hidden variable theory. Several theories of optics. Lamarckian evolution (though epigenetics bears some resemblance). Plenty of theories concerning characteristics of Venus and Mars.

  2. More or less by BenSchuarmer · · Score: 5, Insightful

    Newton's laws have been pretty much settled. Einstein found a way to get more precision under certain circumstances, but Newton is good enough most of the time.

  3. Not a summary by oldhack · · Score: 5, Informative

    That's not a summary, that's a click bait.

    --
    Fuck systemd. Fuck Redhat. Fuck Soylent, too. Wait, scratch the last one.
  4. Science isn't a thing by alzoron · · Score: 4, Insightful

    It's a process.

  5. Re:question objectivity by StefanJ · · Score: 3, Insightful

    "evolutionary criticism . . . is completely forbidden in US schools."

    Well, unless you go to school in one of those states where the school boards also don't think children should be trusted to learn about puberty, carbon dating, and history that wasn't vetted by the Club for Growth and the Daughters of Confederate Heroes.

  6. No by Anonymous Coward · · Score: 4, Insightful

    No amount of experimentation can ever prove me right; a single experiment can prove me wrong.

    -- Albert Einstein

  7. Re:question objectivity by the+gnat · · Score: 3, Insightful

    First class example is that evolutionary criticism (missing intermediate species or disputed claims of finding them, Darwin's doubled-down denial of genetics, etc) is completely forbidden in US schools.

    They're not "completely forbidden", and they're certainly not forbidden in private schools. What is forbidden is using petty nitpicking of details, which are at best only marginally relevant to the validity of evolutionary theory, to advance religious doctrine, which is the only reason these issues are ever raised in the first place. If you want religion taught in public schools, move to Iran or some other country where superstition is mandated by law.

  8. I hope not by Anonymous Coward · · Score: 5, Interesting

    For well over a thousand years Aristotle's work in the physical sciences (including zooology) was considered settled... until people started testing his theories

    We called that period the "Enlightenment"

  9. Science is a Process by SillyHamster · · Score: 3, Insightful

    Not a result. Thus, attempts to claim that the science is settled are attempts to shut down the scientific process.

    If the results of the scientific process are good, they're reproducible, and there's no point in trying to build up a religious dogma of belief on something that simply is.

    Questioning the "settled science" is science. Shut it down at the cost of shutting down science.

  10. Re:question objectivity by Daniel+Dvorkin · · Score: 3, Insightful

    Stalinism

    Is it petty of me to wish that people who accuse their political opponents of being Nazis, Communists, etc., could live for a little while in the world of their paranoid fantasies? If they survived the experience, a month in the actual USSR under Stalin, for example, might give them much more perspective.

    --
    The correlation between ignorance of statistics and using "correlation is not causation" as an argument is close to 1.
  11. Re:question objectivity by Jason+Levine · · Score: 4, Insightful

    First class example is that evolutionary criticism is completely forbidden in US schools

    Or maybe Evolution is just supported by so much overwhelming evidence that 99%+ of scientists accept it as the best theory. Most of the scientific discussions around Evolution are centered around how we dot the i's and cross the t's, not whether Evolution is a better theory than "last Tuesday God said 'abracadabra' and the Universe was formed as is with its 'history' as an illusion."

    In a school's science class, students should learn what the prevailing scientific theories are. They should learn why those theories are the prevailing ones. However, school is not the place for students - who are just learning the material and who will have a highly incomplete knowledge of the subject - to make a determination of which theory is the "right" one.

    Whenever someone says "we need to teach the weaknesses of Evolution", what they really mean is "I would like schools to teach Creationism, but that was struck down by the Supreme Court... as was Intelligent Design... so maybe if we sow enough doubt about Evolution in the students, they'll grow up believing that God created it all 10,000 years ago."

    --
    My sci-fi novel, Ghost Thief, is now available from Amazon.com.
  12. Re:question objectivity by the+gnat · · Score: 3, Insightful

    Is it petty of me to wish that people who accuse their political opponents of being Nazis, Communists, etc., could live for a little while in the world of their paranoid fantasies? If they survived the experience, a month in the actual USSR under Stalin, for example, might give them much more perspective.

    Yes, it's petty, but I do it too, all the time. For instance, just last week I was thinking about how helpful a smallpox epidemic would be in demonstrating why we have vaccines. Likewise, I'd like to see the American Christians who claim to be persecuted spend some time in Saudi Arabia or China so they could understand the true meaning of persecution. I don't actually think any of these people deserve this, but I can't think of anything else that would convince them of how stupid they sound.

  13. A matter of degrees by TheCarp · · Score: 3, Insightful

    I really liked the way one person put it to me a while back. Some people used to have some idea the earth was flat, but then some people realized that wasn't true and said it was a sphere. Well, that was clearly wrong too but a sphere is a lot closer to the truth than flat; treating wrongness as a boolean would just label them both wrong but, one is clearly a lot less wrong than the other.

    So to some degree, it was settled...possibilities were excluded. Then, well its clearly not a sphere, it bulges in the middle, I have heard "slightly pear shaped" is a good description.... then you have the satellites that have precisely measured variations in gravitational field...they have an even more complex picture.

    Whether it is settled or not depends on to what degree you need the answers.

    --
    "I opened my eyes, and everything went dark again"
  14. settled != True by Immerman · · Score: 5, Insightful

    Absolutely. Settled doesn't mean True - science is unconcerned with Truth, perhaps even actively opposed to it. Because there is no theoretical way to distinguish between Truth and an extremely accurate and reliable misunderstanding. Accepting something as Truth denies the ability to challenge it - and those challenges are the very essence of science.

    Settled means it has so thoroughly withstood all challenges that nobody much even bothers to challenge it anymore, and you'd better have some really solid new evidence to back any new challenge or expect to be laughed off the stage.

    This is why the vast majority of anti-AGW positions are considered so ridiculous: The studies they're based on are almost universally either so laughably bad as to be obvious paid "science" propaganda, or are so badly misrepresented that the researchers themselves object to the claims being made by the pundits. Meanwhile the handful of potentially legitimate challenges are largely ignored by the media, presumably because they're either so esoteric they can't be expressed in sound bytes, or so outlandish that only other scientists could take them seriously. Unlike the propaganda being fed to the public, the larger climatology community generally treats those challenges with polite skepticism and constructive criticism because they are at least plausible, even if they need a *lot* more supporting evidence before they could be considered viable alternative explanations.

    --
    --- Most topics have many sides worth arguing, allow me to take one opposite you.
    1. Re:settled != True by greenbird · · Score: 3

      AGW is very likely true, but not at the same level. It is not nearly as well defined: "warming" - is that water temperature, air temperature, total heat content, sea level etc. There is no question that human activity has *some* impact on climate, but that impact is not completely understood and predictable.

      Nor is tested or even really testable for that matter. There's no way you can do an experiment that even remotely tests man's impact on climate. The systematic interactions of a planet's climate are beyond what we can conceive of, much less understand, right now. The whole of scientific method is positing an idea and then doing experiments that prove and experiments that fail to disprove. Note the later. The scientific method demands attempting to disprove what you posit. Anything less is Cargo Cult Science rather than scientific method. This is the problem I see with current climate science. Everything I read is about is science looking for evidence that it's happening and man made. I don't read much of anything about science looking for evidence that it either isn't happening or isn't caused by man.

      --
      Who is John Galt?
  15. Re:Stupid question by Grishnakh · · Score: 3, Insightful

    There's also a difference between observations and theories. For instance, gravity is pretty much "settled". However, it's an observation. We always see that objects are attracted to other massive objects; every time we throw something in the air, it falls to the ground. At this point, it'd be stupid to say that gravity doesn't exist.

    However, whyare objects with mass attracted to other objects with mass? That isn't very well understood. We have a theory that describes the relationship (the universal gravitation theory), in a simple equation that tells you the gravitational force given two objects' masses and distance apart. But why is it so? According to Einstein's theories, it's because the spacetime continuum is warped by mass like a rubber sheet, and gravity is just a side-effect of this. According to Quantum Mechanics, particles called gravitons are responsible somehow.

    So we can debate all day about what exactly causes gravity, but the existence of gravity itself is really undeniable at this point.

    Similarly, with evolution, the age of the earth, etc., the theories might be somewhat debatable (but not nearly as much as gravitational theories), the evidence that led to those theories' creation is pretty undeniable at this point, namely fossils and other geological evidence. Claiming the earth is 6500 years old when there's enormous evidence contradicting that claim is just stupid.

  16. Re:question objectivity by MillerHighLife21 · · Score: 5, Insightful

    First class example is that evolutionary criticism (missing intermediate species or disputed claims of finding them, Darwin's doubled-down denial of genetics, etc) is completely forbidden in US schools.

    They're not "completely forbidden", and they're certainly not forbidden in private schools. What is forbidden is using petty nitpicking of details, which are at best only marginally relevant to the validity of evolutionary theory, to advance religious doctrine, which is the only reason these issues are ever raised in the first place. If you want religion taught in public schools, move to Iran or some other country where superstition is mandated by law.

    The idea that questions about evolution are only raised to advanced religious doctrine is a bit of a religious doctrine in and of itself. Literally the moment that anybody questions anything main stream the immediate response is that those people must be backwoods religious extremists. You see it EVERYWHERE. Somebody raises questions about monetary policy and excessive spending and people immediately go straight to conservative therefore religious. Anybody had the gall to suggest that it was possible for some people to be predisposed to have a negative reaction to something in a vaccine you'd immediately hear "right-wing-religious-nut-job" thrown into the conversation somewhere.

    At some point public branding began happening that if you ever dare to discuss an issue, point out flaws, or raise dare I say "valid" discussion points that your question was invalid simply by invoking "right-wing-religious-nut-job" in the conversation.

    The sheer fact that so many people immediately use that as a go-to rather that even thinking of defending any questions would seem to indicate that those people feel their own doctrine is being questioned, which makes the idea of those people calling others extremist nut jobs kind've ironic.

    One of my all time favorite quotes:

    "The test of first rate intelligence is to hold two opposing ideas in the mind at the same time and still retain the ability to function." - Dwight Whitney Morrow

    There's a lot of people who believe themselves to be intelligent who cannot allow themselves to try to see things from another angle. Nobody holds a viewpoint strongly without having a good reason for doing so. If more people recognized that and tried to understand the other side you'd see a lot less vocal hostility.

    Odds are very good that if you feel strongly about something there are a whole lot of times where you're right and a whole lot of times where you're also wrong.

    --
    "Don't teach a man to fish, feed yourself. He's a grown man. Fishing's not that hard." - Ron Swanson
  17. Means laymen should essentially accept as Fact by ranton · · Score: 4, Interesting

    My interpretation is that there is enough confidence from the scientific community for anyone who is not a scientist researching the topic to accept the current understanding as fact. It doesn't mean they should think it is a fact, just that they should lead their life and form opinions based on the assumption that it is a fact.

    Research should of course continue, probably until the end of time, but at a certain point the general population should no longer question the findings. They simply are not trained enough to form an opinion that differs from the general consensus.

    --
    -- All that is necessary for the triumph of evil is that good men do nothing. -- Edmund Burke
  18. Re:question objectivity by the+gnat · · Score: 4, Informative

    In the past 30 years Darwinists suppressed information about inheritance of acquired traits. The Lamarckian-looking genetics that explain this are now FINALLY being accepted as science and are called, as a group of phenomenon, "epigenetics".

    This simply demonstrates your ignorance of the field. Epigenetics is far more fundamental and complicated than Lamarckian inheritance - it's a basic mechanism of genetic regulation in all multicellular organisms. This wasn't even remotely controversial 15 years ago, when I started studying biology; any freshman biology course would cover the subject. It still isn't terribly well understood, but what can you expect when we still don't know the function of half of our genes?

    What was genuinely controversial was the extent to which epigenetic regulation affected germ cells and was therefore heritable. It was not controversial because "Darwinists" (whatever that means) tried to suppress information, it was because none of the loudest proponents of the theory had found molecular evidence to support it. This is now slowly changing, as biologists are realizing (yet again) that genetic regulation is even more complex than they imagined.

    In any case, none of the new information contradicts modern evolutionary theory; likewise, it does not have any relevance to the issue of whether modern life forms were designed or evolved. It also doesn't overturn the "central dogma" of molecular biology or prove that Lamarck's overall hypothesis was correct. We still have every reason to continue to believe that the unmodified genome is the most important carrier of genetic information and determinant of phenotype, and the extent to which epigenetics is heritable is still an unsolved debate. That makes it a fascinating target for more research, and I'm sure there will be more startling discoveries (and perhaps Nobel prizes) in the near future. I'm also very confident that any new discoveries will be made by actual scientists doing actual research, not theologians.

  19. Re:question objectivity by the+gnat · · Score: 4, Informative

    I have no idea how monetary policy or vaccine reactions are relevant to this debate, or what they have to do with religion. Nor are politics particularly relevant, since you can find scientists of all ideologies working productively without making extravagant pseudo-scientific claims.

    As a biologist, I do know that nearly every single objection I have ever encountered to evolution - and, in particular, common descent, especially as applied to humans and apes - has ultimately been driven by a religious viewpoint, usually a belief in the literal truth of the Old Testament. (I was going to say that the panspermia advocates were the biggest exception, but even they aren't really arguing with the fact of evolution, but the origin of life, which is a different matter.) This goes doubly for the age of the earth, which is even less controversial than common descent. The creationists are also almost uniformly not practicing scientists (or even trained as biologists, in all but a handful of cases); I have yet to meet any biologist who continues to be productive while completely ignoring 150 years of scientific evidence. Conversely, I've known a decent number of biologists who were religious, but did not see the need to distort every scientific finding to fit into their theological worldview. (Francis Collins and Ken Miller are two of the most famous examples, but I've never met them, although I think I used Miller's textbook in high school.) In fact, the one who found "intelligent design" the most infuriating was a conservative Catholic.

    In summary: why shouldn't I assume that creationists are religious? You've given me absolutely no reason to think otherwise.

  20. Re:question objectivity by the+gnat · · Score: 4, Insightful

    My money is being used to expose children to views I don't agree with.

    My money is being used to enforce laws I disagree with, and buy weapons I don't approve of. It's called representative democracy; deal with it, or move somewhere else. We do, however, have a specific clause in our constitution about establishment of religion, and the courts have decided that teaching religion in taxpayer-funded schools is included in this prohibition. (This does not equate to disallowing all criticism of science; you are welcome to spout any nonsense you wish, as long as you do not expect the government to pay for it.) If you're unhappy with that, work on getting the 1st Amendment repealed, or move to another country. I'm sure you won't find much support for teaching evolution in, say, Somalia. (But they're probably not going to be wild about your religion either.)

  21. Re:question objectivity by the+gnat · · Score: 4, Insightful

    How is asking critical questions about view points being pushed onto children with my money establishing religion?

    Stop playing dumb. We all know that the only reason these "critical questions" (which never come from actual scientists) are ever introduced into a classroom is to promote a religious alternative. Pretending otherwise is just disingenuous and insulting. At least Ken Ham has the honesty to admit this is his goal.

  22. Re:Evolution by taiwanjohn · · Score: 3, Informative

    Natural selection comprises two types: ecological and sexual. Both work the same way: An individual passes its genes down more successfully by surviving longer and in good enough health to produce more offspring.

    Ecological selection is what we normally think of as "natural" selection (survival of the fittest). In this case the "selection pressure" is determined by fitness for the environment where one lives. In sexual selection, the selection pressure comes from other members of the species.

    Though they work in similar ways, the two may often be at odds with each other. The classic example would be the peacock's tail, which is "costly" to produce and maintain, and actually makes the bird less well adapted to the environment -- dragging all that plumage around slows him down, making him more susceptible to predation. The only useful purpose it serves is to attract peahens. The peahen's preference for a large, showy tail creates a positive feedback, pushing the peacock's tail to its maximum "survivable" size.

    --
    XML is like violence. If it doesn't solve your problem, you're not using enough of it. --AC