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Interesting vid: Simon Conway Morris answers the question, Is biology structured?

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Simon Conway Morris photo

A good discussion of his field, evolutionary convergence – the same patterns reused again and again in far-distant life forms.

 

 

 

A theoretical physicist from Oxford and a professor of evolutionary paleontology from Cambridge discuss the relationship between chance and evolution – is biology structured?

It’s getting harder to distinguish between a serious look at convergent evolution and ID. Thoughts?

See also: From Cambridge’s Simon Conway Morris: Nine Evolutionary Myths

Comments
Oops. I meant:
The great complexity of biological change from evolution as claimed is beyond loading the dice. It couldn’t be that loaded even if it was!
What makes you think it couldn’t be that loaded, aside from personal incredulity?Genomicus
May 16, 2012
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The great complexity of biological change from evolution as claimed is beyond loading the dice. It couldn’t be that loaded even if it was! What makes you think it couldn't be that loaded, aside from personal incredulity?Genomicus
May 16, 2012
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bilbo 1 The great complexity of biological change from evolution as claimed is beyond loading the dice. It couldn't be that loaded even if it was! Thats the point about mutationism! Modern thinkers have to retreat on these points if evolution is to withstand criticism from equally degree ed critics. The lack of diversity in biology is a problem for evolution which must explain the origin of glorious complexity. So much likeness in structures, forms, processes, and basic themes hints at a thinking being with a plan/program that rules biology just like a plan rules physics. One can predict what will be found in future careful investigation of biology. If evolution retreats to limited options or innate evolved options in biology it will be a paradigm shift that kills off Darwinism as he saw origins. Modern biological investigation always shows an order in biology and not a mishmash as it should be if evolution was true.Robert Byers
May 16, 2012
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Bilbo:
But didn’t Matzke show that all the flagellar components have homologs?
He did not. Out of 42 flagellar proteins in Salmonella, a total of 15 have no known homologs (see his 2006 paper, "From The Origin of Species to the origin of bacterial flagella"; also check out his PT post "Flagellum evolution in Nature Reviews Microbiology"). Further, some of the flagellar proteins (FliF, etc.) only have homologous counterparts in the TTSS. And if the TTSS descended from the flagellum, as I suspect (again, there is disagreement on this issue), these TTSS homologs cannot be evidence that the flagellar proteins were co-opted from precursor parts. FYI: I go into more depth on the whole bacterial flagellum and homology discussion in an article here: http://thegenomestale.wordpress.com/2011/12/25/the-bacterial-flagellum-and-homology/ I should add that my analysis is just a bit off. The flagellar protein FliJ is thought to be homologous with an ATP synthase subunit, namely, the gamma subunit.Genomicus
May 15, 2012
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Seed of Human-Chimp Genomes Diversity http://universe-life.com/2011/07/10/seed-of-human-chimp-genomes-diversity/ 2 Nov,2005 Dov, in biologicalEvolution forum. Biological Evolution’s Seeds of Diversity, Human and Chimpanzee/Bonobo Genomes. Chapter One, In which some wonder what made us human. Three recent quotations from Science, representative of many other recent similar statements in various scientific publications: A) “Understanding the genetic basis of how genotype generates phenotype will require increasing the accuracy and completeness of the currently available chimpanzee genome sequence, as well as sequencing other primate genomes.” B)”Can we now provide a DNA-based answer to the fascinating and fundamental question, “What makes us human?” Not at all! Comparison of the human and chimpanzee genomes has not yet offered any major insights into the genetic elements that underlie bipedal locomotion, big brain, linguistic abilities, elaborated abstract thought, or any other unique aspect of the human phenome.” C)”What makes us human? This question may be answered by comparison of human and chimpanzee genomes and phenomes, and ultimately those of other primates. To this end, we need to understand how genotype generates phenotype, and how this process is influenced by the physical, biological, and cultural environment.” Chapter Two, In which is explained plainly and succinctly the obvious route by which we evolved, i.e. that genotype has not generated phenotype, that we evolved from our genotype via a group of feedback loops. From Science, Vol 308, Issue 5728, 1563-1565 , 10 June 2005, Immunology: Opposites Attract in Differentiating T Cells, Mark Bix, Sunhwa Kim,Anjana Rao: “During differentiation, precursor cells with progressively narrowed potential give rise to progeny cells that adopt one of two (or more) divergent cell fates. This choice is influenced by intricate regulatory networks acting at multiple levels. Early in differentiation, precursor cells show low-level activation of all progeny genetic programs. Bias toward a given lineage comes from environmental inputs that activate powerful positive- and negative- feedback loops, which work in concert to impose selective gene expression patterns”. Chapter Three, In which we explain the revolutionary evolved uniqueness of the human ape’s phenotype: The 6My-old revolutionary life evolution was initiated by our forefathers who adapted from life in semi- or tropical forest circumstances to life on plains. Changes in living posture and circumstances led to modified perceptive/adaptive experiences and capabilities. Developing employment of tools effected enhanced differentiation of hands from legs and enhanced upstanding posturing. As evolving community culture led to language communication humans have gradually replaced adaptation to changed circumstances with self-evolving cultures/civilizations for control and modification of much of their circumstances. This is essentially similar to early life’s celling evolution, but with culture functioning for humans for change/control of circumstances in lieu of genetic and protein toolings that function for the in-cell genomes for adapting their cell’s physiology to changing circumstances. Chapter Four, In which appears, may be, genetic evidence/demonstration of the workings of human cultural evolution. (a) From Science, 2 Sept 2005: “Page’s team compared human and chimp Ys to see whether either lineage has lost functional genes since they split. The researchers found that the chimp had indeed suffered the slings and arrows of evolutionary fortune. Of the 16 functional genes in this part of the human Y, chimps had lost the function of five due to mutations. In contrast, humans had all 11 functional genes also seen on the chimp Y. “The human Y chromosome hasn’t lost a gene in 6 million years,” says Page. “It seems like the demise of the hypothesis of the demise of the Y,” says geneticist Andrew Clark of Cornell University in Ithaca, New York.” (b) But look at this: From Science, Vol 309, 16 Sept 2005, Evolving Sequence and Expression:”An analysis of the evolution of both gene sequences and expression patterns in humans and chimpanzees…shows that…surprisingly, genes expressed in the brain have changed more on the human lineage than on the chimpanzee lineage, not only in terms of gene expression but also in terms of amino acid sequences”. Surprisingly…??? Chapter Five and conclusion, In which I suggest that detailed study of other creatures that, like humans, underwent radical change of living circumstances, for example ocean-dwelling mammals, might bring to light unique evolutionary processes and features of evolutionary implications similar to those of humans. end. Dov Henis (comments from 22nd century) Earth life genesis from aromaticity-H bonding http://universe-life.com/2011/09/30/earthlife-genesis-from-aromaticityh-bonding/ Universe-Energy-Mass-Life Compilation http://universe-life.com/2012/02/03/universe-energy-mass-life-compilation/Dov Henis
May 15, 2012
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Time to update comprehension of Earthlife genesis and its nature: Earth’s Primal Organisms (Per Sleep And Chirality) AAAS Religion-Trade Union Dictates Notwithstanding A. Traces of Inaugural Life Geologists, biologists join forces to tell new stories about the first cells on Earth http://www.sciencenews.org/view/feature/id/340401/title/Traces_of_Inaugural_Life “Earth’s first living organisms didn’t leave behind footprints or bite marks or bones. These single cells thrived quietly in a tiny pocket somewhere on the planet”. B. EarthLife Genesis From Aromaticity/H-Bonding http://universe-life.com/2011/09/30/earthlife-genesis-from-aromaticityh-bonding/ The address of Earth Life Genesis, of phasing from inanimate to animate natural selection, is Aromaticity.Hydrogen Bonding. Dov Henis (comments from 22nd century) http://universe-life.com/Dov Henis
May 15, 2012
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But didn't Matzke show that all the flagellar components have homologs?Bilbo I
May 15, 2012
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OK, Genom, now I understand your position. Thanks.Bilbo I
May 15, 2012
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Well, in the first place, the bacterial flagellum could have been designed into the first cells, because presumably the first cells would have been bacteria, rather than eukaryotes. You can't design a cilium in a bacterium, but you can engineer a flagellum in a bacterium. Secondly, if the bacterial flagellum was front-loaded, we'd expect to see a number of functional precursors (I would imagine anyway, although how molecular machines would be front-loaded hasn't been entirely resolved at all AFAIK), including an export system like the type III secretion system. But IMHO the bulk of the evidence suggests the TTSS arose from the flagellum. So that's one point. And if the TTSS indeed arose from the flagellum (Nick Matzke would argue that the TTSS and the flagellar system both arose from a common export system; to be sure, there is disagreement on that issue), over half of the flagellar components lack any homology evidence for their co-option. This points to a discontinuity between the flagellar system and the rest of the biological universe, and discontinuity is evidence in favor of direct engineering.Genomicus
May 15, 2012
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Now you've got me curious, Genom. Why the one but not the other?Bilbo I
May 15, 2012
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By "engineering" I mean something akin to our engineering of bridges, cars, etc. - in other words, direct intelligent intervention rather than front-loading. I would say that the bacterial flagellum was directly engineered into the first cells, while later molecular machines - cilia, spliceosomes, etc., were front-loaded.Genomicus
May 14, 2012
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I think Mike Gene would say that the first cells were designed with the idea that eventually they would specifically evolve molecular machinery such as the bacterial flagellum, et al. If by "engineered" you mean that there was a precise, step-by-step plan that was followed during their evolution, then I think Mike would disagree. So I'm still not sure what you mean by "engineered."Bilbo I
May 14, 2012
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Hi Bilbo. Sorry for the confusion. Let me see if I can clarify myself. I am very interested in front-loading and I'm focusing on that, primarily. But what I'm saying is this: if I understand Mike Gene's position correctly, molecular machinery like cilia, polyadenylation machinery, and other eukaryote-specific machines, could plausibly evolve without teleology. Whether they did evolve without teleology is another story, but I think he believes that they could evolve without teleology. And this is where I disagree with Mike Gene. IIRC, Mike Gene basically thinks that the bacterial flagellum evolved - and I think that it was engineered. However, I differ from Behe because I think that cilia etc., could be front-loaded, so no direct intervention (either in the form of some quantum-induced mutations or simple protein engineering) would be required except for designing the initial states. Maybe I made things more complicated actually. Feel free to point out anything that isn't so clear.Genomicus
May 13, 2012
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Hi Genomicus, You wrote: I consider myself a “transitional form” between Behe and Mike Gene. I don’t think much of the molecular machinery of the cell could arise through purely non-teleological mechanisms (I believe Mike Gene does, but I’m not sure), but I don’t think intelligent intervention is required either. Thoughts? I'm a little confused by your statement. If I understand him correctly, Mike Gene is working on the hypothesis that the first bacteria and archaea were designed so that random events, such as a bacterium ingesting an archaean, would more likely result in endosymbiosis and result in a eukaryote, which would then have the sort of molecular machinery needed to evolve by random mutaions more complexity. I'm pretty sure Behe would say that additional non-random, coherent mutations would be needed to drive evolution. So where between these two views would you place yourself?Bilbo I
May 13, 2012
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Hi Robert, The question is whether it's possible to get convergent evolution by loading the dice.Bilbo I
May 13, 2012
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AHA. They are feeling the heat of modern investigation. is this a paradigm shift. Not open ended ? Evolution was wrong? Just a few options after all! Oh Brother! Convergent evolution is a error and always was just as evolution is. Its impossible for a random process that is invoked to explain the creation and diversity of glorious biology to suddenly have as tactic number one unidirectionism . Like its got a mind of its own. Like there is a bigger idea behind biology then people understand. Like a bigger thinker. Convergent evolution is the soft underbelly of evolutionism. Its a problem for dice throwing.Robert Byers
May 13, 2012
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Eric Anderson: You made some interesting points I'd like to respond to.
Many people like the idea of front loading in order to accommodate the philosophical idea that the creator or creator(s) of life (whoever that may be) would not interfere with the process once it got started.
I see front-loading as a more testable hypothesis than the ID position Behe et al. are advocating. Front-loading offers a lot of venues for research that could serve to strengthen or falsify front-loading. One of my major concerns with the ID movement is that they aren't generating very many truly testable teleological hypotheses. Front-loading posits that the first genomes on earth were engineered such that certain biological features would be very likely to appear over evolutionary history. The idea of that "nearly every organism is 'front loaded' with the ability to deal with changing environmental conditions" really doesn't capture the essence of the front-loading hypothesis as a hypothesis about the history of life on earth - although what you said is, of course, quite true.
Front loading in the most extreme case, namely that there was no intelligent intervention after the first created organism, requires a truly astounding proposition: that all the complexity and diversity of all life we see around us, every single example of complex specified information, the protein sequences, the DNA, the cellular structures of essentially every organism and so on, were either: (i) specifically programmed into the first organism, or (ii) indirectly programmed into the first organism, in the sense that the various biological structures, sequences, etc. were rendered plausible and likely by a massive reduction in the search space that RM otherwise would have had to traverse. This is an interesting possibility, but requires a leap of programming complexity far beyond what even would be required with direct intervention. Meaning it requires even more intelligent intervention; just earlier in the process.
This is where I think convergent evolution gets interesting. IMHO convergent evolution has effectively demonstrated that the front-loading of specific biochemical systems is indeed feasible. For instance, hemoglobin has evolved independently in lampreys and all other vertebrates IIRC. It thus seems plausible that specific proteins can be front-loaded from initial states. A more dramatic example comes from the evolution of C4 photosynthesis. This biochemical pathway is thought to have evolved independently more than 45 times (see this review by Sage, 2003: “The evolution of C4 photosynthesis”). And C4 photosynthesis is mediated by four different enzymes: pyruvate orthophosphate dikinase, NADP malic enzyme, phosphoenolpyruvate carboxylase (PEPC), and malate dehydrogenase. Why does this demonstrate the feasibility of front-loading? Precisely because it shows that fairly specific targets can be reached by the blind watchmaker independently and multiple times given certain initial states. I like the example of C4 photosynthesis because I think it’s a good illustration of how initial states can shape subsequent evolution, such that the blind watchmaker stumbles upon a certain target - and it's a biochemical system. I consider myself a "transitional form" between Behe and Mike Gene. I don't think much of the molecular machinery of the cell could arise through purely non-teleological mechanisms (I believe Mike Gene does, but I'm not sure), but I don't think intelligent intervention is required either. Thoughts?Genomicus
May 13, 2012
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Hi Eric Anderson. I'll reply to your comments as soon as possible and offer my thoughts on that - stay tuned.Genomicus
May 12, 2012
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Bilbo I, thanks for your comments.
I think another motivation for Mike’s FLE was that Mike already saw Darwinian evolution as a plausible explanation for the development of life, but he didn’t see a plausible explanation for the origin of life.
Well, Darwinian evolution is not a plausible explanation for the development of life, unless one couples it with some kind of planning and guidance. I presume that is what you mean. And, yes, I can see that FLE could fill that role. I tend to be cautious about FLE because I see it has fantastic requirements. Specifically, FLE only has 2 ways to operate: (i) direct programming of all CSI of all life into the initial organism, or (ii) programming of organismal development in such a way that newly-arising CSI of all life becomes, if not inevitable, then at least probable, within the miniscule probabilistic resources available during the history of life on earth. Either approach requires an unfathomable amount of initial programming, likely orders of magnitude greater than what would be required for direct intervention. This kind of "strong" FLE could be right; and that would be very exciting. But it is quite an astonishing proposal. On the other hand, if what an FLE proponent is claiming is that a huge amount of initial CSI is not required, because with a minor tweak to DNA here or a small adjustment to a protein there a subsequent state of development -- including new species, new organs, body plans, etc. -- somehow becomes probably or likely, then what we probably need to do is have that individual revisit the amount of CSI required for the particular state of development and review the awful probabilistic hurdles that have to be overcome to find it.Eric Anderson
May 12, 2012
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Hi Eric, I don't pretend to know all the motivations for Mike's front-loaded evolution (FLE) hypothesis. I think one of them was just to pursue the idea of directed panspermia -- would it be plausible that life on earth had been seeded by ET? Thus untethering ID from theological commitments. I think another motivation for Mike's FLE was that Mike already saw Darwinian evolution as a plausible explanation for the development of life, but he didn't see a plausible explanation for the origin of life. Given that even the simplest cells looked intelligently designed, this might be worth exploring, but how? I think his coming up with the idea of Foresight was probably a focal event. Could one find evidence that the cell was designed with the future in mind, not just survival, but future evolution? And I think Mike has succeeded in discovering quite a bit of evidence for Foresight. Is it enough to explain all of life's natural history? I don't know. But I follow his blog (designmatrix.wordpress.com) and wonder if he'll ever write another book. If he does, I'm sure it will be worth reading. Meanwhile, I think when we are talking about convergent evolution, FLE comes naturally to mind as a way of explaining how it might happen: different types of organisms arrive at the same evolutionary answers because they began with the same "toolkits." That's why I would like to know more about what the "ingredients" of the various similar structures consist of.Bilbo I
May 12, 2012
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Genomicus:
In short, Mike Gene’s IHE hypothesis would seem to suggest that certain amino acid substitutions are more likely than others given a specific initial sequence. The effects of the IHE could be quite interesting when you put it up against the initial states.
I have great respect for Mike Gene and his insights. I also think there is something to be said for the possibility of front loading. Sometimes I wonder, however, about the value of the front loading idea and how far it can be taken. Specifically: - Many people like the idea of front loading in order to accommodate the philosophical idea that the creator or creator(s) of life (whoever that may be) would not interfere with the process once it got started. Front loading is therefore a defense against the long-made evolutionary attack on special creation which argues that regular and repeated intervention in the history of life is something no self-respecting creator would do. Front loading seeks to deflect this attack by postulating that new biological features can come about at specific times or in particular circumstances without the undesirable (to some people) idea of ongoing intervention by an intelligent agent. Front loading may be factually true, but in this very common usage it is being used as a defense against a philosophical, rather than a scientific, position. There is no sound philosophical reason to think that a creator would not subsequently intervene in creation; and, therefore, no rational scientific need to push all design to the initial stage of creation. - Front loading, broadly understood, simply means that there is information in the organism that can respond to particular circumstances (say certain environmental stresses) to the benefit of the organism. In that broad sense, front loading is clearly true. Indeed, organisms are clearly programmed to be able to respond to their changing environments in many ways. Even things that were once thought to be RM+NS in action, such as certain hyper-mutation rates in bacteria, are now known to be triggered and to some extent controlled, by the organism's programming. There is still room for the NS on the end of the equation, but the RM is not really RM. Thus, front loading is clearly true -- almost a given, really -- with any organism that has the ability to respond to the environment in a way to preserve its life or increase its likelihood of survival, rather than just being passively acted upon. Stated more bluntly, nearly every organism is "front loaded" with the ability to deal with changing environmental conditions. - Front loading in a broader sense -- new body plans, new complex functional specified information -- is worth contemplating. Yet unless we are able to identify specific instances in which an environmental trigger would exponentially increase the likelihood of a particular biological change coming into a being, a change that, by definition, must be significant enough for NS to operate and for the new trait to become fixed in the population, then the idea remains just a hypothetical possibility. - Front loading in the most extreme case, namely that there was no intelligent intervention after the first created organism, requires a truly astounding proposition: that all the complexity and diversity of all life we see around us, every single example of complex specified information, the protein sequences, the DNA, the cellular structures of essentially every organism and so on, were either: (i) specifically programmed into the first organism, or (ii) indirectly programmed into the first organism, in the sense that the various biological structures, sequences, etc. were rendered plausible and likely by a massive reduction in the search space that RM otherwise would have had to traverse. This is an interesting possibility, but requires a leap of programming complexity far beyond what even would be required with direct intervention. Meaning it requires even more intelligent intervention; just earlier in the process. ------ Apologies for the long comments, but I wanted to lay this out a bit. My assessment is that front loading is clearly true in the basic sense. In the larger sense it is interesting, worth pursuing, and may be true in some cases, but unfortunately is often directed toward and constrained by a philosophical idea (no subsequent intervention) that need not be true.Eric Anderson
May 11, 2012
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Hi Genomicus, I'm afraid you're going to places well above my pay grade as an armchair philosopher.Bilbo I
May 11, 2012
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Hi Tragic Mishap, In The Edge of Evolution, Behe argued that Darwin was right about common descent, but wrong that random mutations could account for all of it. As Behe concluded on p.83: "To account for that [the tree of common descent]...multiple coherent genetic mutations are needed.Bilbo I
May 11, 2012
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Bilbo: Quite true. In short, Mike Gene's IHE hypothesis would seem to suggest that certain amino acid substitutions are more likely than others given a specific initial sequence. The effects of the IHE could be quite interesting when you put it up against the initial states. I am wondering if cytosine deamination could even be used to front-load the molecular machinery that Behe says would require intelligent intervention to originate.Genomicus
May 11, 2012
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Hi Genomicus, I think Mike Gene's point about cytosine deamination was that it would make certain types of amino acid changes more likely once a random mutation occurred, not that it would guarantee that certain mutations would indeed occur. Behe's brand of ID says that specific mutations in natural history were intelligently determined.Bilbo I
May 11, 2012
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(1) There are only a few ways of doing things, so evolution’s bound to find them over and over again.
That's just wrong, lol. Having only one solution to a problem doesn't increase the likelihood of finding it to a certainty. The rarity of being dealt a royal flush in poker doesn't increase the odds you'll be dealt one. Why should things be any different with evolution?Mung
May 11, 2012
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If I may interject. Behe doesn't care about natural history. He only cares about demonstrating the inadequacy of Darwinism. He doesn't have a theory about the "history of evolution."tragic mishap
May 11, 2012
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Bilbo:
Mike Gene, on the other hand, is working on the hypothesis that after the first cells were designed, no further non-random mutations were required.
But the front-loading hypothesis can also involve mutations that were more or less "programmed" to occur based on the initial states, can it not? I have cytosine deamination in mind here, wherein - a la Mike Gene's IHE hypothesis - an initial sequence is "programmed" to develop into another sequence through cytosine deamination. Thoughts?Genomicus
May 11, 2012
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Eric, "- Even if there were only one way of doing things from a macro-scale engineering standpoint (by definition, the only thing natural selection can care about), there is no reason to believe the underlying molecular, or even proteomic details have to be convergent." Indeed, and protein homoplasy appears pervasive as well. Jonathan McLatchie's review of George McGee's Convergent Evolution highlights several examples: Dolphins and Porpoises and...Bats? Oh My! Evolution's Convergence Problem "We have no reason to think that a particular lineage of organisms would have developed a particular trait, except by looking at it after the fact and saying, “Well, gee, it has the trait, so it must have been driven toward it.”" Just add a dash of Weak Anthropic Principle and conclude that, if evolution didn't cause the development of that trait, we wouldn't be observing it. ;-) And then there's still that pesky issue of a mechanism.material.infantacy
May 11, 2012
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"(1) There are only a few ways of doing things, so evolution’s bound to find them over and over again." True, this is an argument an evolutionist would likely make in light of convergence. Difficulties that quickly spring to mind about this line of argumentation, however, are as follows: - We don't in fact know that there are only a few ways of doing things, so this is really an argument from ignorance. - In cases where we do see lots of variety it is clear there are many ways of doing things. (e.g., how many ways are there to move about on the land or move through water?). - Even if there were only one way of doing things from a macro-scale engineering standpoint (by definition, the only thing natural selection can care about), there is no reason to believe the underlying molecular, or even proteomic details have to be convergent. - The "few ways" hypothesis still doesn't explain how or why particular traits arose. For example, even if we grant that a particular physical trait exists in widely-separated organisms (say, sonar ability), there is absolutely no reason to think that chance and necessity would drive organisms toward any such solution. I'm not talking about probabilities here (which doom any such story in their own right), but rather the simple fact that we know there is no environmental or selection imperative driving organisms toward a particular "solution" by the very reality that there are numerous creatures, even creatures within the same environment, that don't have the feature and do very nicely without it, thank you very much. We have no reason to think that a particular lineage of organisms would have developed a particular trait, except by looking at it after the fact and saying, "Well, gee, it has the trait, so it must have been driven toward it." ------- At the end of the day, the only logical answer evolution has to offer to the convergence question is this: "Stuff happens." A logical answer. Just not a very satisfying one.Eric Anderson
May 11, 2012
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