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Pittsburgh Professors Challenge Darwin

Syberghost writes "Darwin's Theory of Evolution comes under an interesting attack from an American anthropologist and an Italian biochemist, according to an article from University of Pittsburgh's school newspaper. In a nutshell, Schwartz and Maresca argue that change is not gradual as Darwin stated, but comes rapidly in response to drastic mutations caused by shifting environmental conditions."

41 of 193 comments (clear)

  1. Pardon my ignorance but by BitterAndDrunk · · Score: 5, Insightful

    Isn't that simply punctuated equilibrium? I'd thought it was already considered part of current evolutionary theory. I'm a neophyte so I'm probably way off; someone correct me. (and no FSM references please; they're already hack and it's under a year old)

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    1. Re:Pardon my ignorance but by vitamine73 · · Score: 2, Informative

      I have read their original research, put this clearly seems to be a new form of Gould's and Eldredge's theory.

    2. Re:Pardon my ignorance but by poopdeville · · Score: 3, Informative
      Yes, punctuated equilibrium. For the uninitiated, imagine a differentiable manifold called 'utility'. Evolution drives to maximize utility, but it's easy to get stuck in local maxima. That's when an ecosystem is in equilibrium. It takes drastic environmental change to knock everyone out of that local maximum and maybe look for a new one.

      On another note, Darwin supports his theory of evolution. He looks like a monkey!

      --
      After all, I am strangely colored.
    3. Re:Pardon my ignorance but by lgw · · Score: 4, Insightful

      I agree with your analysis. How is this new at all? We've know for decades that simple mutation-and-selection doesn't drive change anywhere near fast enough to account for history. The current theory as I know it as a layman is that occasional periods of rapid change are needed, and no biologist has believed in "Darwinian" evolution for generations.

      I suspect these fellows have some interesting new postulate, and the Pitt News just got it wrong.

      --
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    4. Re:Pardon my ignorance but by the+gnat · · Score: 3, Insightful

      It takes drastic environmental change to knock everyone out of that local maximum and maybe look for a new one.

      I've never been clear on the distinction between P.U. and catastrophism (not in the Velikovsky sense, though). When I first learned about the fossil record, a major point was the mass extinctions that have occurred throughout history. The "Cambrian explosion" is thought to have followed the extinction of >80% of all species, where entire phyla were wiped out. Perhaps not coincidentally, all modern phyla were present in the Cambrian era. (If memory serves there were several even worse extinctions that followed.) The naive but obvious conclusion I drew from this is that massive changes in ecosystem and depopulation of niches increased the potential for adaptive radiation as organisms moved into new niches. This would also mean that more mutations might yield an increase in fitness, since what determines fitness would be so drastically different. In a stable ecosystem, in contrast, niches don't get emptied or added and hence populations stay more static.

      Is this part of the modern evolutionary theory? (I am a biophysicist, but I don't know much about evolutionary theory.)

    5. Re:Pardon my ignorance but by gansch · · Score: 4, Insightful

      Although this is similar to punctuated equilibria, it is not appear to be identical. In punctuated equilibria, there are periods of statis with little evolution of new species, interspersed with periods of rapid speciation in many species. This theory seems to apply more to single species, in which the number of individuals with a recessive mutation reach some sort of critical mass, at which time the recessive trait manifests itself and speciation occurs.

    6. Re:Pardon my ignorance but by Elwood+P+Dowd · · Score: 2, Informative

      MrFlibbs' highly rated comment above is suggesting that this theory says environmental stresses could lead to simultaneous mutations in different members of the same species, and the species wouldn't necessarily need a common ancestor for each individual gene. That's certainly different from punctuated equilibrium.

      There's nothing in the article that leads me to that reading, though, so yeah, either MrFlibb read the actual research and found something more than the article, or this sounds like total crap.

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    7. Re:Pardon my ignorance but by Lifewish · · Score: 2, Funny

      imagine a differentiable manifold

      You aren't a mathematics student by any chance are you? I hope to god you are otherwise I shall lose all faith in the human race...

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    8. Re:Pardon my ignorance but by poopdeville · · Score: 2, Interesting
      I'm a mathematician, not a biologist. But I've studied all sorts of models of evolutionary development as part of a computational class in the philosophy of life and artificial life. From what I've gathered, your insights are indeed a part of modern evolutionary theory. However, the theory is very fragmented. As I mentioned, there are many competing models for evolutionary development that fit within the known empirical data. They're all nice models, but more information is needed before any one of them can be chosen as the favored model. In particular, there is no known mechanism causing sudden and massive evolutionary shifts of the sort necessary for punctuated equilibrium to occur. They just seem to sort of happen, even in the computational models. (Cue rants about intelligent shifting)

      If you're interested in this material, take a look at "An Introduction to Artificial Life" (I think) by Adami. Mark Bedau's work is also very accessible (though I might be biased since he taught the class). Last I checked, the wikipedia entry on artificial life was pretty good, and had a lot of other references.

      --
      After all, I am strangely colored.
    9. Re:Pardon my ignorance but by hotspotbloc · · Score: 2
      FTA:
      "If you look at the fossil record, organisms didn't gain new items like teeth and jaws gradually," Schwartz said. "It's not like fish developed bony teeth one piece at a time. It happened suddenly."
      BitterAndDrunk said:
      "Isn't that simply punctuated equilibrium?"
      Bingo! Stephen would be quite pround of you. =)

      http://en.wikipedia.org/wiki/Punctuated_equilibriu m
      http://en.wikipedia.org/wiki/Stephen_Jay_Gould

      --
      "I hate to advocate drugs, alcohol, violence or insanity but they've always worked for me" - HST
  2. Must... not... troll... must... debate... politely by Jim+in+Buffalo · · Score: 2, Funny

    Shifting environmental conditions which are, of course, controlled by the Intelligent Designer, allowing Him... I'm sorry, uh, it to create all these diverse forms of life in just six thousand... oops, did it again, sorry, a few million years. (Seriously, though, did you read some of the comments posted on that page that TFA is on? Yikes!)

    --
    This sig, aah-ah, is comin' like a ghost-sig...
  3. Misleading, sensationalist headline. by TripMaster+Monkey · · Score: 5, Insightful

    The title of TFA reads, "Professor Challenges Evolution", when in fact he is doing nothing of the sort.

    From TFA:
    Schwartz refuted Darwin's theory of gradual evolution in organisms with one that states that evolution occurs quickly and suddenly as the result of cell mutations.
    While Schwartz is challenging a specific premise of evolutionary doctrine, he is by no means refuting the entire theory. Apparently, Nan Ama Sarfo felt the story would be read more if it appeared to jump on the anti-evolution ID bandwagon.

    Shame on you, Nan.
    --
    ____

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    1. Re:Misleading, sensationalist headline. by greginnj · · Score: 4, Insightful
      Shame on you, Nan.
      Don't blame Nan, the prof set her up:
      "Darwinism's presence in science is so overwhelming," Schwartz said. "For the longest time, there was no room for alternative thinking among the scientific community."
      Point one, he's feeding her the extremism, she isn't including it herself. Second, his second line is complete and utter bs. As others have noted, this warm-over of punctuated equilibria is a challenge to Natural Selection as the mechanism of evolution, not to evolution itself. Doing science is always about challenging the previous order -- it's only the stuff that's new and different that even gets published.

      But why is he doing this? Here's a clue:
      Jeffrey Schwartz -- a Pitt professor in the department of anthropology and the department of history and philosophy of science ...
      Hmm, interesting fields he's in. Just like Steve Fuller did in the Dover ID trial, some people in philosophy of science have a vested interest in creating the appearance of warring camps of ideas rather than evidence-based epistemology. To paraphrase them, 'science is about persuading people, not proving ideas'.

      One more thing,Schwartz has been pushing this idea for 6 years, it's not new news even for him:

      Book Review published in 7/2000
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    2. Re:Misleading, sensationalist headline. by sp3d2orbit · · Score: 2, Informative

      "As others have noted, this warm-over of punctuated equilibria is a challenge to Natural Selection as the mechanism of evolution, not to evolution itself. "

      I'm not sure what side you are on, but it needs to be made clear that punctuated equilibrium DOES NOT challenge natural selection as the mechanism for evolution. Punctuated equilibrium simply refines the time scales over which natural selection works.

      If, for example, the Great Rift Valley in Africa warmed significantly over a few hundred thousand years, this is a natural event. And, if that warming caused forest to turn into plains, this is a natural event. And, if that lack of forest cause certain monkeys to develop taller posture and longer gaits so that they could survive in the new climate, this is a natural event selecting better adapted species to survive. Both Darwin's original theory and P.E. are in agreement on the fact that nature selects the survivors; P.E. simply says that it can happen faster than we thought.

      P.E. makes total sense from a mathematicall standpoint. Imagine a cartesian plain (landscape) made up of peaks and valley representing the probability of an animal surviving given a certain set of features. Peaks are successful combinations of features, valleys are combinations that would lead to certain death. In other words, each peak is a niche. At the very beginning of life the landscape is open with successful niches. Randomly combining a set of features will put you, on average, halfway between a peak and valley. So long as no other creatures exists at a higher level on your particular peak, you are the most successful and will probably survive. Moreover, at the beginning of time, it is almost as likely for you to make a huge evolutionary jump and land at another successful niche at another peak. But, over time, creatures evolve to their niches and climb higher on the mountain. Over time it becomes mathematically unlikely to jump from one peak to another AND be more successful in that niche than the existing life forms. Creatures tend to become better and better adapted to their own peaks by making small, tuning changes.

      When the equilibrium is punctuated the landscape changes suddenly. Successful niches become deadly and vice versa. The probability of successfully jumping from one peak to another increases, and so does the apparent rate of evolution. That's why evolution seems to work in spurts. We see evidence of this happening again and again: the transition of single celled to multicellular, the age of amphibians, the age of reptiles, the age of dinosaurs (different), the age of mammals, etc. Each age represents a time when life jumped from one configuration to another quickly and then spent millions of years honing those features.

  4. Damn Professors! by commodoresloat · · Score: 4, Funny

    I don't want to start a holy war here, but what is it with these Pittsburgh professors repudiating the open source core of Mac OS X? Darwin is a solid UNIX foundation for a great operating system; if these professors can't see that, they must not understand how intelligently designed it is!

    1. Re:Damn Professors! by Eccles · · Score: 2, Funny

      Ironically, Darwin evolved, as does all code, through intelligent design.

      Umm, not all code...

      --
      Ooh, a sarcasm detector. Oh, that's a real useful invention.
  5. Before this devolves into an ID blast-fest ... by MrFlibbs · · Score: 4, Insightful

    ... please RTFA. All the guy is saying is that sudden changes are brought about by environmental stress creating recessive genes, and these bring about rapid changes in a population after the recessives start combining in offspring.

    The only feature of classic Darwinism that he's refuting is about a single organism's offspring being the only one with the new trait. Interesting notion, but hardly revolutionary.

  6. -1, deceptive headline by Stoutlimb · · Score: 4, Insightful

    How much more inflammatory can one get? The article should read "Scientists debate the details of how evolution happens." Talk about being deliberately inflammatory.

  7. Punctuated Equilibrium by CODiNE · · Score: 2, Insightful

    As has already been posted, this is a well known theory and as far as I know what the currently accepted evolutionary model suggests.

    I think the point he's making is that it's simply not being taught. I know plenty of people (especially on Slashdot) who still believe the old "millions of years of small gradual changes" bit. Natural selection and gradual modification MAKE SENSE to most people and seems fairly persuasive, but it's not really what happened. Honestly I think it's a bit of bait 'n switch... explain evolution one way to a person, then later on "Oh by the way nobody really believes that."

    --
    Cwm, fjord-bank glyphs vext quiz
    1. Re:Punctuated Equilibrium by JohnFluxx · · Score: 2, Insightful

      And I know lots of people who still think that momentum = mass * velocity. Maybe we should write an article saying that I've proved physics wrong because schools teach it incorrectly. Or maybe we should realise that people learn things in stages - simplistic explanation first.

  8. It's not news, it's a PR piece. by TCQuad · · Score: 3, Interesting

    I suspect these fellows have some interesting new postulate, and the Pitt News just got it wrong.

    From the banner at the top of the site, the Pitt News is a student newspaper. Student newspapers quite often do little fluff pieces on professors in various departments.

  9. I liked this theory bettery... by rdwald · · Score: 3, Informative

    ...when Gould came up with it 20 years ago.

    Seriously, is the author of TFA a moron or what? Punctuated Equilibria is not the same as "Science is wrong!!!11one"

  10. this poor researcher by mrpeebles · · Score: 3, Interesting

    Can you imagine how this poor guy must feel? You try to publish some paper (I don't know how important it is), the popular press picks up on it and headlines it with "Professor challenges evolution." I for one know that if this happened to a friend of mine, I would tease them about it for YEARS.

  11. Poppycock by the+eric+conspiracy · · Score: 4, Insightful

    The concept that the idea of rapid change is a revolutionary attack on Darwinism is poppycock.

    Darwin's thesis is in two parts - that evolution occurs, and that the mechanism is natural selection. The first part is not under any scientific debate. The second part, the proposal that natural selection is the mechanism has been understood to be not the best mechanism for the process of evolution has been understood for nearly 100 years. Darwin did not understand genes, genetics, nor the mechanisms of genetic drift that occur within populations. This knowedge postdates Darwin's original work.

    The understanding of evolutionary mechanism works at the level of genes, and populations whereas Darwinism was concerned mainly with species.

    This view of the mechanism of evolution is widely misunderstood in the creationistic and anti-evolution communities, and ignorant articles often appear trying to discredit evolution based on a fundamental misappropriation of the topic.

    It's a shame that this sort of article was published on Slashdot - it shows a great ignorance of the topic.

  12. Why is it one or the other by Swisssushi · · Score: 3, Interesting

    As with so many arguments in society and science, people almost always need to choose one side or the other. In the evolutionary theory debates, the battle between the gradual change camp and the punctuated equilibrium camp has been going on for a long long time. As an antro major, we discussed both ideas in class, but really never talked about "what if it's both". The idea that change is always gradual has its merits in that biology is always trying little experiments in adaptation (e.g. mutations). Most don't work, but some get to hang around and eventually get expressed rather regularly in a population. Then, under a specific stressor, those organisms with that trait suddenly have an advantage over their brethren. The ones without this nifty trait die off leaving the ones with the trait. This gets seen as a sudden adaptation in the fossil record, even though the development of the trait was gradual. In general, biology doesn't work fast enough to respond to rapid environmental stressors. Biology of different organisms work along the same time lines as the organism's reproductive cycles. Bacteria can change more quickly than apes because bacteria reproduce much more quickly, but relative to the organisms themselves, the changes are slow.

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  13. I RTFA... by Spy+der+Mann · · Score: 2, Interesting

    This theory states that on radical environment conditions, some naturally-produced "mutation inhibitors" are reduced, creating mutations in large populations. These mutations are invisible, i.e. in the form of recessive genes, until two individuals with the same gene have an offspring.

    Of course, nothing guarantees that the offspring won't be a horrible mutant and die because of an "unknown disease".

    1. Re:I RTFA... by usrusr · · Score: 2, Interesting

      while this is interesting, don't we, as double-helix driven beings, have a lot of dormant genes that are only triggered by extreme environmental conditions?

      these things could mutate over hundreds of generations without ever harming individual fitness and then suddenly get triggered, exposing a shitload of mutations at once, spread in different variations over the whole population.

      Those new findings would only strengthen an already strong mechanism.

      --
      [i have an opinion and i am not afraid to use it]
  14. ID will miss the lesson by MuNansen · · Score: 3, Insightful

    What's funny is that this article is a great example of how evolution isn't a dogma. The scientific community is constantly seeking to improve or amend it. Insteal the ID'ers (funny how close that is to "idolaters") will just use the headline "Scientists disprove Evolution."

  15. Actual article by Schwartz and Maresca by Bowling+Moses · · Score: 4, Informative

    The actual article is available from The Anatomical Record Part B: The New Anatomist" volume 289B, Issue 1 , Pages 38 - 46. The abstract's free, although the article itself may require a subscription or university account. The flareup seems to be with this sentence in the abstract (I haven't read more yet): "In evolutionary terms, extreme spikes in environmental stress make possible the emergence of new genetic and consequent developmental and epigenetic networks, and thus also the emergence of potentially new morphological traits, without invoking geographic or other isolating mechanisms." In other words, a change in the environment puts organisms under extreme stress, overloading the ability of various DNA repair mechanisms to counteract DNA damage and mutation, occasionally resulting in novel, beneficial mutations. Several other posters have already said this really isn't anything new, for instance it's known that some bacteria actively mutate their DNA in response to extreme environmental stress. The author (Schwartz) may be hyping his claims some, but really it looks like a case of the reporter going gonzo, and might be a creationist yahoo to boot.

  16. RTFA by LightningBolt! · · Score: 3, Funny

    Their not repudiating Evolution! They're simply saying that it runs faster on "Schwartz and Maresca" than it does on Darwin. Although the article doesn't say it, I'm pretty sure "Schartz and Maresca" is a Linux distro, a.k.a. "S&M Linux".

    --
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  17. Luria and Delbruck by milamber3 · · Score: 2, Informative

    Wasn't this whole debate put to rest in the luria and Delbruck experiments where they showed random mutation leads to resistance not acquired immunity? Basically showing that the enviromental condition doesn't lead to the evolution it's all random.

  18. Whether or not you consider evolution to... by Expert+Determination · · Score: 3, Insightful

    ...be "gradual" or "sudden" is a function of the granularity you work at. If you take a broad overview of evolutionary history then it looks very gradual. An expert in bivalves might consider the lengthening of a shell by 2mm in a time too small to discern from the fossil record as something sudden whereas most people, in particular those studying evolution for the first time, would be entirely justified in considering the change to be gradual. So please, if you're going to argue about this, define your terms.

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  19. I wrote a reply to that effect: by Morosoph · · Score: 5, Insightful
    Given the modern controversy over the role of natural selection, the article is misleading, and the headline is wrong.

    The professor hasn't challenged evolution by natural selection, but rather gradualism, as did Steven J. Gould. Darwin did posit gradualism, so an accurate headline would have been to say that the professor had challenged Darwin. As it is, it appears that it is the theory of evolution, rather than the detail of Charles Darwin's theories that is being challenged.

    The article is to be commended upon the elucidation of the "dual mutation theory"; is it a shame that it did not make clearer that this theory restores natural selection to the driving seat.

    This is important, since responsible editing that promotes truth over political advantage should seek avoid false inferences from being drawn by the less sophisticated.

    Faithfully,

  20. Not a challenge at all by 955301 · · Score: 3, Insightful

    Please, stop with the sensationalism.

    All this means is that the size of a step in a particular direction an animal can take can be large to accomodate a large environmental impulse. But most environmental changes are gradual and therefore most responses are as well. Otherwise there would be big oscillations, e.g., an ostrich has a parakeet which has a penguin, etc.

    Control system 101. The guy just thinks the steps can be greater than we imagine. Makes sense since we don't get many opporunities to experience significant changes.

    --
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  21. One tooth at a time by gorrepati · · Score: 2, Insightful

    It is common knowledge that Darwins theory does not specifically goes into details, but gives a general framework to think evolution of organisms in. Though it is not proved, people in the community have a sense that some mutations are not gradual, and evolution does not solve some problems twice. Genetic code contains a lot of junk, but people do feel that junk has a purpose like memory about past problems. Coming to the funny part, as this guy states about evolution, fish did not ever try to grow one tooth at a time. It probably occured by hardening the jaw first, having some divisions in the jaw, having harder parts on top of the jaw(Called the tooth) and having many tooth. I seriously doubt wether this guy knows Darwins evolution at all..

    --
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  22. Re:Whoa... Pitt news by gyepi · · Score: 2, Informative

    Agree. The article contains many misunderstandings. And, by the way, the article states that he is a professor in the department of history and philosophy of science - actually, he is only an affiliated/adjunct faculty member. (I am a phd there.)

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  23. Pittsburgh Profesors Challenge Darwin by Mr.+Shotgun · · Score: 2, Funny

    SUNDAY! SUNDAY! SUNDAY!
    Be at the Pennsylvania state fairgrounds!

    As the Deadly duo

    The Pittsburgh Professors
    challenge the
    Father of Modern Biology

    Charles Darwin
    to a handicap grudge match in the steel cage.

    It promises to be a match the world will never forget as high flying theories and hard core evidence are used to bash each others skulls in.
    The Violence! The Pain! The pure Savagery! This match is not for the faint of heart, only come if you want pure action.
    Ticket are on sale RIGHT NOW! So go get some, and we'll see you sunday!

    --
    Of all tyrannies, a tyranny sincerely exercised for the (supposed) good of its victims may be the most oppressive
  24. Seems like a good time to discuss misconceptions by plunge · · Score: 2, Informative

    This article, in a word, is bunk. The claims this guy is making are goofy and demonstrably misinformed about what evolutionary theory is.

    Some basic background:

    Punk eek was opposed to phyletic uniformatism/gradualism (which many consider to have been a cheap straw man anyway). This was a debate over macroevolutionary history: the patterns of large scale morphological and species change. Contrary to popular opinion, macroevolutionary change is subject to all sorts of different forces: things like large scale, genetic drift, extinction events, and so on. No biologist claims that natural selection is the only factor in the particular history of life on earth.

    This guy is is not talking about things on the scale of punk eek. He's talking about things on the scale of microevolution, and what he's proposing seems to be a form of saltationism. At best, he's attacking a purported gradualism in actual mutation rates (which itself is nonsense: it's mainstream genetics that different species have all sorts of different mutation rates as well as different rates of morphological change). But for all the rhetoric, nothing he says that's actually correct is even slightly revolutionary. At best, he's proposing another mechanism for variation: variation that involves "good tricks" in a certain genomic sequence that environmental stressors can make happen in many different individuals at once. But variation of ANY sort still just provides the raw material for natural selection to work on. And without natural selection at work, mutation would still be just ultimately random garbage. It's only by placing mutations through the sieve of actually being expressed in individuals that any information about the environment can be imprinted onto a given gene pool. That's the only way we know of that random jostling can be transformed into functional movement. For the mutations to somehow "predict" or "will themselves" to happen in certain linked ways that have a non-random purpose requires some other mechanism, and this guy proposes nothing.

    And that's me being the most charitable. Most of the rest of what the guy says is just total nonsense. For instance, he implies that cellular repair systems resist mutation (heck, he even speaks about whether they "willingly" resist change or not!). Well... yes. But they fail. All the time. Most everyone reading this has recent and unique several mutations, right now. And that's not even to mention that you'd have to be grossly misinformed about Darwin to think that "Darwins theory" says ANYTHING about genetic mutation. Darwin hadn't a clue what genes or DNA or the rest of it even were! All he spoke about was the differential success of different variations. Of course, what Darwin thought is irrelevant trivia to what is true in biology, but still, this guy is just showing both his ignorance and his obsession with the idea that Darwin is some sort of "high priest" whom he is fighting against.

    Now consider this: "according to Schwartz, mutations occur recessively and are passed unknowingly until the mutation saturates the population. Then, when members of the population receive two copies of the mutation, the trait appears suddenly."

    Either the reporter got this wrong, or this guy is really misinformed. Mutations can be recessive or dominant. Nothing about them makes them occur "recessively" only. While the scenario he describes can and does happen (recessive traits that don't really start appearing in force in a population until they become near fixed), nothing about it is particularly revolutionary. And something with complex functionality and specification like fully formed "teeth" is not going to evolve completely out of sight, unexpressed, and then burst onto the scene all at once. That, kids, is called saltation, and while big saltationist jumps can certainly happen (and can spring out via the recessive/dominant pathway), they are very very very unlikely to ever hit upon something functional and useful. Remember: only the actual testing

  25. Evolution of theories by VincenzoRomano · · Score: 2, Insightful

    I think that none should trash any theory, unless there are some clear evidences and, much better, when there is one theory able to provide answers when the other ones cannot.
    Evolution theory seems to be quite reasonable because it seems to rely on very few postulates when compared to other theories.
    If other theories need fewer postulates and provide more answers, then chances there are that they will succeed.
    I'd suggest a quick read of "The Fabric of reality" by David Deutsch for deeper details about this philosophy.
    In any case theories about evolution are themselves subject to evolution whenever the objective is to provide answers.

    --
    Maybe Computers will never be as intelligent as Humans.
    For sure they won't ever become so stupid. [VR-1988]
  26. Playing with words by MarkusQ · · Score: 2, Insightful

    Changes in the statistics of the presence of genes in a population over time is evolution.

    No, this is a meme of the anti-evolution crowd (part of the "scientists dispute evolution" nonsense) that is to often repeated by loose-thinking scientists and popularizations. You are confusing one of the intermediate effects of evolution (an effect which, as you note, could have multiple causes apart from evolution) with evolution itself. Lets see how that sort of fuzzy thinking looks like in another environment:

    Changes in the statistics of the presence of the sun in a the sky over time is the heliocentric theory of the solar system.

    To which, of course, you reply: No, no, no! The heliocentric theory of the solar system explains why we see the sort of pattern of sunlight that we do--it isn't just the change in sunlight, but a specific theory that predicts why we see the sort of patterns of change of sunlight that we do.

    Same deal in evolution. Or to bring it on home: giraffes, bats and whales all had a reasonably recent common ancestor. There is no reason what so ever for genetic drift to have taken this common ancestor towards any of the three forms in particular. The amazing fact is, we do not find whales grazing the savanna, bats swimming in the open sea, and giraffes hanging upside down in caves. The odds against the situation we do see are already pretty steep, and when you throw in polar bears, monkeys, elephants, house cats, foxes, and so on it gets down right amazing that every population seems to have "drifted" from the common ancestor in a way that suited its environment.

    Now, the genetic drift idea just leaves this hanging out there, and doesn't even attempt to offer an explanation (which is why the closet Intelligent Design people keep trying to keep it in play). But Darwin makes a bold prediction; this directed change is not the result of any magical force, but rather the effect of a simple, natural process; the change was random, but the maladapted variants died off at a faster rate than the rest. In the ocean, bat-like mutations just didn't do as well as the whale-like mutations.

    There are many studies of such populations in absence of at least known natural selection factors that show evolution (changes in gene distribution statistics).

    Same problem: evolution isn't just change, it's adaptive change.

    While genetic drift is a stochastic process, an allele is truth state, and eventually it will propagate throughout the population, or disappear completely.

    Granted. But it's a string of nonsequitors.

    The power of genetic drift effects can be seen in a striking example in the human race - every living human has mitochondrial DNA originating from a single female. There are many other examples of human populations (where natural selection is generally not a factor) that for one reason or another are genetically isolated and are quite divergent in their genetic statistics.

    This is another Intelligent Design meme: that some how, humans are magically out of reach of natural selection now. It is completely unfounded--unless you are claiming that something like "everyone has exactly the same number of children" or "people's inherited characteristics have no effect on their breeding success", you'll see it as soon as you stop to think about it.

    But in any case, even if it wasn't begging the question, why should we be the least bit surprised about the mitochondrail DNA?

    The evidence is pretty clear that genetic drift is an important cause of evolution. Some feel it is more important than natural selection.

    The evidence is smoke and mirrors and the people who have been taken in by it either 1) have an agenda or 2) aren't thinking very clearly. You can trot out all the "experts" that you want, but if an idea doesn't hold water (or, as in this case, needs a supernatural entity to care the w

    1. Re:Playing with words by MarkusQ · · Score: 2, Insightful
      evolution isn't just change, it's adaptive change.

      Sorry, that is just not correct. Evolution is NOT defined in modern biology as adaptive change. Your basic premise is wrong, making your arguments specious.

      Funny, I feel the same way about your argument. A quick google shows about a 50/50 split in the definitions which specify "adaptive change" (in some form or another) as opposed to the ones such as you site. To give just a few examples:

      But, as I pointed out, this isn't a problem that can be solved with dueling citations; even starting down that path misses the fundamental point that genetic drift alone can't explain any of the key observations about life:

      • It is very diverse
      • The diversity is (to a good first approximation) perfectly adaptive
      • When you drill down to a more detailed accounting it is still adaptive, but at the level of genes, not individuals or populations (e.g. see Dawkins "Extended Phenotype")
      • It is optimal, in the sense that permuting the diversity in any way (e.g. hanging giraffes from cave roofs) would destroy one or more of the points above.
      So if you define "evolution" as above, you wind up faced with the fact (from your source) that "Drift produces evolutionary change, but there is no guarantee that the new population will be more fit than the original one. Evolution by drift is aimless, not adaptive." and you have done nothing but muddy the waters. By calling every change "evolution" you admit more causes which can do nothing to explain anything that needed explaining.

      For example, suppose a new school of "economic biologists" broadened the definition of evolution still further, to include (say) a change in the average market value of a member of the species or the number of books in which it is mentioned. What good would that do? Now there would be a whole bunch more things that could cause "evolution" but they would have done nothing to clarify the question--instead, they would have confused things horribly.

      And that, pretty much, is what "population genetics" has done. The questions are murky enough at the level of the individual organisms, but by considering populations you effectively average out all the interesting questions and wind up making vacuous statements such as "genetic drift causes evolution" where "genetic drift" is defined (again from your source) as what happens when, by chance "the frequency of an allele may begin to drift toward higher or lower values."

      Combining this with your definition of evolution, we have:

      The frequency of an allele drifting toward higher or lower values causes changes in the statistics of the presence of genes in a population over time.

      Which, as I hope you can see, has no explanatory value whatsoever and makes no testable predictions to speak of (though the converse would be world shaking news).

      --MarkusQ