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Darwinism vs. convergence: Another round to convergence


Why doesn’t this The Scientist feature, with Richard P. Grant interviewing Yale Passamaneck (March 31, 2011) fill me with confidence about the long slow march of Darwinian evolution?:

What can a clam-like creature tell us about eye evolution? Quite a bit, as it turns out. We ran a news article at the beginning of the month, on the finding that brachiopod, or lamp shell, embryos have eyes that are more closely related to those of vertebrates, than of their spineless cousins.

Here’s the original article, where Amy Maxmen explains “Eye evolution questioned: Invertebrates with vertebrate-like vision challenge the idea that the two groups of organisms have distinctly different visual receptors” (1st March 2011):

In 2004, biologists hypothesized that an ancestor of both invertebrates and vertebrates sensed light with rhabdomeric receptors — but also had ciliary receptors embedded deep within their brains, where they have been found in marine worms and bees, and might have sensed patterns, such as the lunar cycle. As vertebrates evolved, ciliary receptors theoretically migrated towards the body surface and became the primary tools for sight.But the new results challenge this scenario with the discovery of surface ciliary photoreceptors in the larvae of marine invertebrates called brachiopods (Terebratalia transversa), shelled creatures that have been around for 540 million years. Passamaneck and his colleagues identified the expression of a gene characteristic of ciliary receptors, ciliary-opsin, in cells in the light-sensing “eyespot” of larval brachiopods.

Is “diverged from a common ancestor” more plausible  than “aiming at a common target”? Why?

Why is it beginning to seem more and more like the real story is Darwinism vs. evolution?

I do not understand you comment on Darwinism vs. Evolution. If you think that they run counter to each other and are mutually exclusive, please explain. Yossarian
Confess I don't understand all the fuss here about "convergence". Surely there are numerous well-accepted examples of convergent evolution, such as the streamlined shapes of fish and marine mammals, eyes in molluscs and vertebrates, etc. Surely one might expect adaptation to the same environmental niche might involve similar body changes? In what way is convergence somehow a challenge to conventional evolutionary theory, and in what way does it lend support to ID? And anyway, is not the article quoted (about the brachiopods) actually a challenge to the "conventional" convergent evolution explanation, in favour perhaps of some, hitherto unsuspected, ancient common feature? Or have I misunderstood? Capt. Haddock
To touch on convergent evolution and the fossil record: In many instances convergence is shown to extend to the molecular level (requiring the same molecular sequences) instead of just the morphological level (looking the same), thus convergence, at such a deep level, points very strongly to the reuse of 'optimal' designs for certain features in life instead of the 'happenstance' ability of evolution to find novel islands of functionality; Convergence Drives Evolution Batty - Fazale Rana - September 2010 Excerpt: The multiple, independent origin of echolocation in these animals (twice in bats and once in toothed whales) exemplifies convergence,,, When examined from an evolutionary perspective, convergence doesn’t make much sense.,,, the latest research demonstrates that—again, from an evolutionary perspective—the genetic and biochemical changes that account for the emergence of echolocation in bats and dolphins is identical. Given the random nature of the evolutionary process, this recent discovery doesn’t match what evolutionary biologists would expect to find. But both the discovery and convergence make sense if life stems from the work of a Creator. http://www.reasons.org/convergence-drives-evolution-batty ,,,evolution is shown to be 'historically contingent'; Lenski's Citrate E-Coli - Disproof of Convergent Evolution - Fazale Rana - video (the disproof of convergence starts at the 2:45 minute mark of the video) http://www.metacafe.com/watch/4564682 The Long Term Evolution Experiment - Analysis Excerpt: The experiment just goes to show that even with historical contingency and extreme selection pressure, the probability of random mutations causing even a tiny evolutionary improvement in digestion is, in the words of the researchers who did the experiment, “extremely low.” Therefore, it can’t be the explanation for the origin and variety of all the forms of life on Earth. http://www.scienceagainstevolution.org/v12i11f.htm ,,, Conway Morris seems to be adamant that the fossil record is a point in favor of evolution, and this is indeed his field of expertise, yet from this article I read yesterday, from no less luminaries in the field of paleontology than Conway Morris is we find; That quote!—about the missing transitional fossils Excerpt: One of the most famous and widely circulated quotes was made a couple of decades ago by the late Dr Colin Patterson, who was at the time the senior paleontologist (fossil expert) at the prestigious British Museum of Natural History. So damning was the quote—about the scarcity of transitional forms (the ‘in-between kinds’ anticipated by evolution) in the fossil record—that one anticreationist took it upon himself to ‘right the creationists’ wrongs’. He wrote what was intended to be a major essay showing how we had ‘misquoted’ Dr Patterson.1 This accusation still appears occasionally in anticreationist circles, so it is worth revisiting in some detail. Dr Patterson had written a book for the British Museum simply called Evolution.2 Creationist Luther Sunderland wrote to Dr Patterson inquiring why he had not shown one single photograph of a transitional fossil in his book. Patterson then wrote back with the following amazing confession which was reproduced, in its entirety, in Sunderland’s book Darwin’s Enigma: ‘I fully agree with your comments on the lack of direct illustration of evolutionary transitions in my book. If I knew of any, fossil or living, I would certainly have included them. You suggest that an artist should be used to visualise such transformations, but where would he get the information from? I could not, honestly, provide it, and if I were to leave it to artistic licence, would that not mislead the reader?’ He went on to say: ‘Yet Gould [Stephen J. Gould—the now deceased professor of paleontology from Harvard University] and the American Museum people are hard to contradict when they say there are no transitional fossils. … You say that I should at least “show a photo of the fossil from which each type of organism was derived.” I will lay it on the line—there is not one such fossil for which one could make a watertight argument.’3 http://creation.com/that-quoteabout-the-missing-transitional-fossils bornagain77
Is “diverged from a common ancestor” more plausible than “aiming at a common target”? Why?
(a) we see common ancestry - look at any family tree or animal pedigree. We also have more indirect evidence, based on similarities (e.g. apes are more similar to each other than to dolphins). I hope the mechanism for this is obvious. (b) There is little or no evidence for "aiming at a common target". In particular, there is no evidence for a mechanism to account for this. The best evidence seems to be that some species have converged to be similar. But it usually turns out that the details are different (e.g. flight in vertebrates has evolved 3 times, but different bones have elongated each time. It's not clear to me that this particular piece of work even shows convergent evolution: from the article it looks like we don't really know what happened, and this new work has added to the picture. Heinrich
It is amazing that Conway Morris cannot see his own bias. He clearly imposes what he wants to see on the evidence. He alluded to at least two appearances of the flagellum in life to say 'they must have evolved', yet no one has any clue how any molecular machine whatsoever 'evolved', much less just bacterial flagella. The Cell as a Collection of Protein Machines "We have always underestimated cells. Undoubtedly we still do today,,, Indeed, the entire cell can be viewed as a factory that contains an elaborate network of interlocking assembly lines, each which is composed of a set of large protein machines." Bruce Alberts: Former President, National Academy of Sciences; in spite of the fact of finding molecular motors permeating the simplest of bacterial life, there are no detailed Darwinian accounts for the evolution of even one such motor or system. "There are no detailed Darwinian accounts for the evolution of any fundamental biochemical or cellular system only a variety of wishful speculations. It is remarkable that Darwinism is accepted as a satisfactory explanation of such a vast subject." James Shapiro - Molecular Biologist The following expert doesn't even hide his very unscientific preconceived philosophical bias against intelligent design,,, ‘We should reject, as a matter of principle, the substitution of intelligent design for the dialogue of chance and necessity,,, Yet at the same time the same expert readily admits that neo-Darwinism has ZERO evidence for the chance and necessity of material processes producing any cellular system whatsoever,,, ,,,we must concede that there are presently no detailed Darwinian accounts of the evolution of any biochemical or cellular system, only a variety of wishful speculations.’ Franklin M. Harold,* 2001. The way of the cell: molecules, organisms and the order of life, Oxford University Press, New York, p. 205. *Professor Emeritus of Biochemistry, Colorado State University, USA Michael Behe - No Scientific Literature For Evolution of Any Irreducibly Complex Molecular Machines http://www.metacafe.com/watch/5302950/ “The response I have received from repeating Behe's claim about the evolutionary literature, which simply brings out the point being made implicitly by many others, such as Chris Dutton and so on, is that I obviously have not read the right books. There are, I am sure, evolutionists who have described how the transitions in question could have occurred.” And he continues, “When I ask in which books I can find these discussions, however, I either get no answer or else some titles that, upon examination, do not, in fact, contain the promised accounts. That such accounts exist seems to be something that is widely known, but I have yet to encounter anyone who knows where they exist.” David Ray Griffin - retired professor of philosophy of religion and theology List of 40 Irreducibly Complex Molecular Machines which Defy Darwinian Claims http://creationbydesign.wordpress.com/2010/06/15/list-of-40-irreducibly-complex-molecular-machines-which-defy-darwinian-claims/ bornagain77
Nullasalus, And they engage in obvious question begging. "Indeed, convergence points in exactly the opposite direction because supposedly “irreducibly complex” structures, such as the bacterial flagellar motor, evolved independently at least twice." This shows that they obviously have not thought about intelligent design enough to take it seriously. Convergence is strong evidence FOR design, not against it. Collin
Actually, what's really sad about the Map of Life site is the "second aim": Second, that evolution repeatedly navigates to stunningly similar solutions from very different starting points. Through the surprisingly ubiquitous process of convergent evolution, organisms as distantly related as moths and birds, ciliates and worms, when inhabiting similar environments, have developed similar features as adaptive solutions to life there. This suggests that evolutionary outcomes can be much more predictable than generally thought, and raises interesting questions about how patterns of convergence arise. ...You know, I can't help but think that the "second aim" of the site is really the "first aim". But the authors of it are so paranoid at being associated with ID in any way, shape or form that they can't bring themselves to discuss convergence in evolution without mangling ID in an almost purely "for show" way. nullasalus
Speaking of convergence, I was just over at the Map of Life, the Templeton project of Simon Conway Morris & co. The site vaguely hints at direction and purpose in evolution. But under "Aims of this website", I found this: Of note, the science of evolutionary biology is NOT consistent with the central tenet of the “intelligent design” (ID) movement that suggests, contrary to all scientific evidence, that amongst other things organisms were supernaturally created and have remained unchanged since the time of their creation. There is also NO evidence for biological structures being supposedly “irreducibly complex”, arising by non-evolutionary “processes”. Indeed, convergence points in exactly the opposite direction because supposedly “irreducibly complex” structures, such as the bacterial flagellar motor, evolved independently at least twice. Not only that but we understand how each of the component parts became adapted make the complex structure that exists today. The existence of change over time in living things is clearly manifest in the fossil record, and is supported by information from the molecules, form and behaviour of organisms alive today. Really? That's what the central tenet of the Intelligent Design movement is? That organisms were supernaturally created and have remained unchanged since the time of their creation? ID is opposed to evolution, and must entail "non-evolutionary processes"? No evidence that some biological structures are "irreducibly complex"? Really? None whatsoever? We have the bacterial flagellum figured out (we must, because we've identified biological precursors, therefore..?)? I wish people who were anti-ID would at least get ID straight. nullasalus

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