tag:blogger.com,1999:blog-37148773.post8154091116414453160..comments2024-03-19T00:24:23.577-04:00Comments on <center>Sandwalk</center>: Junk & Jonathan: Part 4—Chapter 1Larry Moranhttp://www.blogger.com/profile/05756598746605455848noreply@blogger.comBlogger49125tag:blogger.com,1999:blog-37148773.post-72465098519051580582011-11-12T16:27:20.065-05:002011-11-12T16:27:20.065-05:00What is called a "junk DNA" is also a re...What is called a "junk DNA" is also a record of mutations that appear to be associated with the origin of species.<br /><br />"Junk DNA" represents mostly families of repeats generated by transposable elements (TEs). Fixation of TEs by genetic drift in small populations may cause them to "drift apart" and become founder populations for new species.<br /><br />See:<br /><br />http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3183009/Unknownhttps://www.blogger.com/profile/02050699392314587992noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-4793094842725277062011-05-29T20:20:41.014-04:002011-05-29T20:20:41.014-04:00According to Dr. Moran
"There are two possib...According to Dr. Moran <br />"There are two possibilities here. Either Wells is deliberately misleading his readers by emphasizing that speciation must occur by natural selection or he's ignorant of modern evolutionary theory."<br /><br />The other possibility is that Dr. Moran does not have a clue about what constitutes "modern evolutionary theory". As we can see by his breathtaking reversal in his post. <br />But then who does a have a clue about what constitutes "modern evolutionary theory"? Apparently Coyne, who is "one of the world's leading experts on speciation".<br />doesn't know.<br /><br />But Dr. Moran continues blithely on his way - lecturing the rest of us.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-37148773.post-25524948570675111042011-05-29T11:12:26.930-04:002011-05-29T11:12:26.930-04:00Dr. Moran originally posted:
"That's in l...Dr. Moran originally posted:<br />"That's in line with modern evolutionary theory and Coyne should know because he's one of the world's leading experts on speciation."<br /><br />Then suddenly Dr. Moran reverses himself completely and just goes on. <br /><b>This is absurd. </b><br />Whatever Dr. Moran thinks modern evolution theory is, it can turn into its opposite and nobody is supposed to notice. <br /> <br />Do we need any better example of the bankruptcy of evolution theory thinking?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-37148773.post-31213540782460957112011-05-29T10:57:41.007-04:002011-05-29T10:57:41.007-04:00Dr. Moran posted:
"I don't know for sure ...Dr. Moran posted:<br />"I don't know for sure whether Wells intends to emphasize speciation by natural selection when he claims that, "biologists had still not observed the origin of a new species ("speciation") by natural selection." If that's his intent then it's true that there are very few examples of true speciation (biological species concept) that can be attributed directly to natural selection. As Jerry Coyne points out, reproductive isolation is mostly due to accident (random genetic drift) and not natural selection [The Cause of Speciation]. That's in line with modern evolutionary theory and Coyne should know because he's one of the world's leading experts on speciation. [UPDATE: Coyne and some commenters have corrected me. Coyne actually does think that most speciation is due to natural selection. I'll stick with Futuyma as my authority. He's much more open to the idea of speciation by random genetic drift (Evolution 2nd ed. p. 447)] "<br /><br /><b>How in the world could Dr. Moran, who presents himself as an expert, get the part that is stroked out wrong? </b>Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-37148773.post-37846991544018116182011-05-26T17:39:00.334-04:002011-05-26T17:39:00.334-04:00As to the idea that reproductice isolation is equa...<b><i>As to the idea that reproductice isolation is equal to "true speciation"...</i></b><br /><br />This is a "no-macro evolution" argument, and totally stupid. It basically argues that if we see species change enough they don't breed, that doesn't mean that a lizard, in a few million years, won't produce both other *drastically different* lizards, and birds. Its just another variation of "god of the gaps". "Ah, ha! You proved that speciation has happened, but not that speciation of *kinds* does, until you do that, God can still be hiding in there some place, making both seals and dogs out of their 46 million year old ancestor. So there!"<br /><br />The same question on that comes up over and over, and they have no answer, "Why, if you can prevent two new species from breeding via isolation, is it then somehow, according to you, impossible for additional changes to make them completely different, over tens of millions of years of such isolation?" The answer seems to be, invariably, "Well, just because I say so!"<br /><br />Oh, and yeah, Moran, you can feel free to steal my "peer reviewed whining". ;) lolKagehihttps://www.blogger.com/profile/09037921279395746555noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-41831345454618791182011-05-25T20:52:03.066-04:002011-05-25T20:52:03.066-04:00john Harshman says,
So let this be a lesson to us...john Harshman says,<br /><br /><i>So let this be a lesson to us all to read our sources carefully.</i><br /><br />I did read my sources carefully. What I didn't read was his book on speciation where he apparently was more clear about his real position.<br /><br />BTW, I do remember one or two times when you were right and I was wrong. :-)<br /><br>Larry Moranhttps://www.blogger.com/profile/05756598746605455848noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-46858139474945709282011-05-25T18:43:35.232-04:002011-05-25T18:43:35.232-04:00Why is so important to fight against the idea that...<i>Why is so important to fight against the idea that reproductive isolation (true speciation) might just be an evolutionary accident?</i><br /><br />I don't think it is, and I even think the way in which we study speciation might bias the our estimates of how important selection is. I just wanted to point out you were saying something different than Coyne would. <br /><br />As to the idea that reproductice isolation is equal to "true speciation"... species can can remain quite distinct even with odd insertion of genes from another lineage, so I don't think we should tie species-hood on any one character (even if lack of gene flow makes species, it doesn't have to be the <i>sine qua non</i> of them.David Winterhttps://www.blogger.com/profile/09704684760112027351noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-47306698119575510322011-05-25T18:11:48.504-04:002011-05-25T18:11:48.504-04:00Kagehi says,
... peer reviewed whining ...
I lov...Kagehi says,<br /><br /><i>... peer reviewed whining ...</i><br /><br />I love it! Can I use it?<br /><br>Larry Moranhttps://www.blogger.com/profile/05756598746605455848noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-1617361385306556952011-05-25T17:39:03.595-04:002011-05-25T17:39:03.595-04:00As has been observed before, the War on junk DNA i...<b><i>As has been observed before, the War on junk DNA is yet another way in which an unwarranted desire for specialness exposes itself.</i></b><br /><br />Actually its dumber than that. The people doing the whining think that the way to get a point across is to just whine more, and louder, and find some big names to support them. Worse, if you tell them, "Where is your peer reviewed work.", they respond with peer reviewed whining and demands that we recognize the authority of which ever big names they imagine they have found (even if they have to misrepresent, misunderstand, and misuse, without permission, those big names). The one thing they don't do, since they don't have labs, or research, is actually support there assertions, without relying on cherry picking research of people that actually are doing such detailed examination of genetics, by showing what all the DNA they insist isn't really junk actually *does*.<br /><br />They actually think that just making up hypothesis, or assertion, like, "its front loaded stuff for use later, or in the past", or, "it has to do something, so you can't be right", or, "some badly done math by someone that, at this point, doesn't even qualify as an idiot savant, says its not possible for it to happen!", constitutes science. They literally seem to think that all real researchers do all day is the same thing, i.e., sit on their asses, writing papers, and thinking, instead of actual work. Its like telling your accountant he is, "over paid, doesn't do anything, anyone could figure out your taxes, no matter how complicated they are, and the reason is because God wouldn't have designed the tax code, and the economy, if it wasn't intended to be 'simple'. After all, those out of work people, failed companies and gross inefficiencies are all just myths!" If someone said that, other than maybe a Libertarian, they would be dragged off to the nearest loony bin, or, at the bare least, no accountant would sell them services ever again, if the insulted one could stop it. But, its the same stupid argument we get from IDiots about DNA.Kagehihttps://www.blogger.com/profile/09037921279395746555noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-41879055287794248022011-05-25T17:12:24.398-04:002011-05-25T17:12:24.398-04:00Homology is a circular argument, according to Well...<i>Homology is a circular argument, according to Wells, so you can't use homology as evidence for evolution.</i><br /><br />I suppose that Wells likewise dismisses all evidence of neutral molecular evolution garnered from the statistical study of homologous genes that have no selective advantage, while that dismissal of evidence supports his claim that God doesn't make junk DNA.<br /><br />(I have not read all the comments, so somebody might have already noted this.)James Goetzhttps://www.blogger.com/profile/02412501436355228925noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-52778268534494843042011-05-25T15:24:03.765-04:002011-05-25T15:24:03.765-04:00Larry,
I've heard back from Jerry Coyne and y...Larry,<br /><br /><i>I've heard back from Jerry Coyne and you guys are correct!</i><br /><br />You say that as if it's a shock to find me correct in anything. I assure you that I have been correct on several previous occasions in my life also. I even like to think that I'm correct much of the time. Of course, much of the time I agree with you.<br /><br />So let this be a lesson to us all to read our sources carefully.John Harshmannoreply@blogger.comtag:blogger.com,1999:blog-37148773.post-62814430041807821112011-05-25T14:25:29.072-04:002011-05-25T14:25:29.072-04:00@David Winter and John Harshman,
I've heard b...@David Winter and John Harshman,<br /><br />I've heard back from Jerry Coyne and you guys are correct!<br /><br />Here's what Coyne says.<br /><br /><i>I think you 've got me wrong on two accounts (you can post this if you'd like):<br /><br />1. When I say that speciation is often (not always) an "accident"--I mean that reproductive barriers are accidental byproducts of genes that diverged for other reasons. That is not genetic drift, but pleiotropy, and <br /><br />2. As we show in chapter 11 of our book (Speciation, by Coyne and Orr), the evidence is that most reproductive barriers resulted from genes that diverged by natural selection, not genetic drift. Hypothesis that reproductive isolation results from genetic drift are not supported by either theory or experiment. Thus, as far as we can see, speciation usually esults from natural selection, although the reproductive barriers may be pleiotropic byproducts of the genes that diverged by selection. That does not rule out the involvement of drift completely, but we know of very few cases where it is implicated (a chance in chirality of snails, from right- to left-handed coiling or vice versa, may be one such case).<br /><br />So I think you're mistaken in saying that I think speciation results largely from drift. I think this comes from your misinterpretation of what I meant when I say that speciation is a "genetic accident."</i><br /><br>Larry Moranhttps://www.blogger.com/profile/05756598746605455848noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-9942658281534422052011-05-25T11:35:11.832-04:002011-05-25T11:35:11.832-04:00@David Winter and John Harshman,
I stand by my st...@David Winter and John Harshman,<br /><br />I stand by my statement about Jerry Coyne and speciation. You should read his posting <a href="http://whyevolutionistrue.wordpress.com/2010/12/08/reinforcement-and-the-origin-of-species/" rel="nofollow">Reinforcement and the origin of species</a>. <br /><br />Populations that are geographically separated will evolve independently by natural selection and random genetic drift. Many studies have focused on natural selection as the mechanism of divergence because that's the most interesting example to most biologists. <br /><br />Whether or not these diverging populations become "species" depends on whether they evolve mechanisms that ensure reproductive isolation. <br /><br />As Coyne says,<br /><br /><i>Genetic barriers aren’t thought to arise for the purpose of keeping species distinct. Rather, they are usually thought to be evolutionary accidents: geographically isolated populations diverge genetically under natural selection or other evolutionary forces like genetic drift, and that divergence leads to the evolution of genetic barriers (mate discrimination, the sterility of hybrids, ecological differences, etc.) as byproducts of evolutionary change. </i> <br /><br />The "byproducts" aren't selected. <br /><br />Coyne is interested in those rare cases where reproductive isolation is actually an adaptation that occurs when the two populations are in contact. This is an exception to the rule.<br /><br />Now I understand the models involving epistasis where it's possible that the different alleles affecting reproduction may have been adaptive in both populations but those are special cases of the more general phenomenon. <br /><br />Why is so important to fight against the idea that reproductive isolation (true speciation) might just be an evolutionary accident?<br /><br>Larry Moranhttps://www.blogger.com/profile/05756598746605455848noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-70795003979927248432011-05-24T23:08:57.230-04:002011-05-24T23:08:57.230-04:00These are great posts Larry,
But I think you'...These are great posts Larry,<br /><br />But I think you've got Coyne wrong. He's quite clear the he means the genetic differences that underly reproductive isolation in "secondary contact" usually arise from selection in one or both nascent species during their physical isolation. Chapter 11 of <i>Speciation</i> if very explicit about this.David Winterhttps://www.blogger.com/profile/09704684760112027351noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-29511220073647148812011-05-24T20:55:18.355-04:002011-05-24T20:55:18.355-04:00amphiox says,
But among prokaryotes (no mitchondr...amphiox says,<br /><br /><i>But among prokaryotes (no mitchondria) DNA replication really does eat up a significant chunk of the energy budget, and extra useless DNA really does constitute a competitive disadvantage.</i><br /><br />It's really hard to calculate the metabolic cost of junk DNA, even in prokaryotes.<br /><br />About 80% of the genome of a typical bacterium is transcribed and during a single life cycle there will be several hundred transcripts produced from each gene (on average). That's a lot of nucleic acid—about one hundred genomes worth. And it doesn't even begin to account for all of the other things going on inside the cell. <br /><br />Every generation, for example, the cell has to double the amount of membrane and cell wall and that's much more costly than replicating a bit of extra DNA.<br /><br />We don't know exactly why bacteria have so little junk in their genomes but it's unlikely to be a simple matter of metabolic cost.<br /><br>Larry Moranhttps://www.blogger.com/profile/05756598746605455848noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-38405527557488646332011-05-24T20:33:50.922-04:002011-05-24T20:33:50.922-04:00Kahegi, thanks for the great explanation. I would ...Kahegi, thanks for the great explanation. I would add that the mitochondria is the far greater enabled than multicellularity. There are some single-cell eukaryotes that have lots of junk DNA. (There are some amoebas with more DNA than humans, for example).<br /><br />But among prokaryotes (no mitchondria) DNA replication really does eat up a significant chunk of the energy budget, and extra useless DNA really does constitute a competitive disadvantage. And guess what? Bacteria have virtually no junk DNA.<br /><br />This is true even for aerobic bacteria, even the close relatives of the putative ancestors of the mitochondria. What eukaryotes have that no prokaryote does is the ability to have lots of mitchondria at once, and to make more when energy demands go up.amphioxnoreply@blogger.comtag:blogger.com,1999:blog-37148773.post-55254625995523913232011-05-24T19:48:39.312-04:002011-05-24T19:48:39.312-04:00If the non presence of junk DNA were evidence in f...If the non presence of junk DNA were evidence in favor of intelligent design (it's not, but bear with me), the scientific reaction would not be to write a novella of misrepresentation, weasel-wording, and Humpty-Dumptifying bent on reducing the definition of "junk DNA" to mean "no DNA at all".<br /><br /><br />It would be to conclude that design played a significant role in the development of prokaryotes, but little or no role in eukaryotes.<br /><br />Without a narcissistic view of the importance of eukaryotes - and particularly a certain eukaryotic species - the conclusion that design played a significant role in prokaryotes, but not eukaryotes would be extremely interesting, but by no means cause to take up an ideological sword against the dragon of junk DNA.<br /><br />As has been observed before, the War on junk DNA is yet another way in which an unwarranted desire for specialness exposes itself.llewellyhttps://www.blogger.com/profile/16001213921499191213noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-38582376693534884902011-05-24T18:34:02.144-04:002011-05-24T18:34:02.144-04:00Larry, you are misreading Coyne. Even the quote yo...Larry, you are misreading Coyne. Even the quote you give in The Cause of Speciation", if you read closely, is a paraphrase of what I said (or, rather, what I said is a paraphrase of Coyne). Read his book. Selection is a much stronger cause of the sort of divergence that results in speciation than drift is. See especially Chapter 11, from which I quote: "There is now considerable evidence that natural ans sexual selection pay a role in speciation. This evidence derives from a wide variety of studies: laboratory experiments on divergent selection, molecular analyses, comparative contrasts, and, perhaps most important, case studies. In contrast, firm evidence for the role of genetic drift in speciation is rare. Indeed, it is hard to point to any examples other than chromosomal speciation in plants and mice, and unusual cases of shell coil-reversal in snails."<br /><br />And, later in the same paragraph: "It appears, then, that at least one important debate has been settled: selection plays a much larger role in speciation than does drift."<br /><br />You may not agree with Jerry (though I do), but let's not confuse his position. (Unless it's changed radically since 2005, and I'm unaware of any such change.)<br /><br />I repeat that you are missing the distinction between selection having speciation as an accidental byproduct (what Coyne is arguing for) and selection that is directly aiming for speciation. It's the former that is common, while the latter is rare.John Harshmannoreply@blogger.comtag:blogger.com,1999:blog-37148773.post-56709545187425234512011-05-24T18:24:33.288-04:002011-05-24T18:24:33.288-04:00But it doesn't work like that. Selection is al...<b><i>But it doesn't work like that. Selection is all-pervading. If 50% of the genome were really useless, selection would whittle it down, as it has done in countless examples where even something functional imposed too high a metabolic cost on the organism.</i></b><br /><br />Actually I will even go one step farther. The cost is like your computer CPU, to use that as an example. If you have an ENIAC, you are limited by what it can access in memory (number of switches that existed), what it can access in storage (it didn't have any), and how much it can do at once (one thing, and one things only). If you have a quad core 64-bit processor... Well, lets put it this way, modern machines have terabyte drives, can, in theory, support close to a terabyte of RAM, and can run a lot of things at the same time.<br /><br />Now.. You will note there are limitations anyway. We can't cram enough cores into one to run *everything* you might ever install at one time. There is also, likely, a functional limitation on how big a single cell could get too (the size determining how much you can do at one time). Even the fact that we use quad cores, instead of just a really fast single core, is a limitation. We had to go multi-cellular to make it work, in effect. Even computers have such limits, so you can't ever get as much RAM as you can in theory use, for example.<br /><br />But, living cells have other limitations that computers don't. A lot of it has to be running, constantly, in parallel, and swapping of active and inactive stuff has to go one all the time, basically like a CPU swapping out data between various places. If you even *tried* to run a modern OS on an 8086 (1Mhz), it would take a year just to load, and another year to start an application. On a modern machine, you can do all of that *very fast*.<br /><br />But, here is the point. We have specialized stuff that helps. We have GPUs, to handle the graphics, we have FPUs, to handle math, we have special bits that provide easier data movement to and from the various places it needs to go. In short, even a modern quad core, without all that stuff, would be 100 times slower than it is.<br /><br />So, what does that have to do with DNA? Well, up to the physical limit, you can expand memory and storage without limit (size of the cell and nucleus). There is no certain idea as to what the upper limit is, though some things may have gotten close. But, to do this, you need power to push the system, and that comes from mitochondria. They give us what single cell organisms don't generally have. A power source that lets the thing be a quad core, lets it have 1 terabyte of RAM, lets it have 2 terabytes of storage, and lets it move all this stuff, without worrying about how much of it is useful or not.<br /><br />Now, look at your modern computer, as an organism. Instead of running 1-2 very specialized processes, with minimal, or even no, display, streamlined to do specific tasks, and where you have to be *very* careful that everything fits in the space available, you have mad variation in display, thousands of independent functions, etc. And, buried in all of that are office documents you never finished, notes you made and forgot about, bits and pieces of stuff that where once working, but got replaced, viruses that got in, etc. Piles of stuff that either does nothing now, but did at one time, or never did anything, or where experimental, or just change the color of the display cursor.<br /><br />Multi-cell organisms, with the inclusion of mitochondria, gained the equivalent of a Hemi engine, while the single cell organisms remained stuck with bicycle peddles. There is so much waste energy available that the effect is like loading 4 people in your car, instead of 2. Hardly enough to require worrying.Kagehihttps://www.blogger.com/profile/09037921279395746555noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-57157280943303751012011-05-24T18:13:23.301-04:002011-05-24T18:13:23.301-04:00The Cambrian Explosion "contradicts Darwin...<i>The Cambrian Explosion "contradicts Darwin's theory that major differences should arise only after millions of years of evolution ...."</i><br /><br />The Cambrian "explosion" was, what, 50-100 million years long? So Darwin's guesstimate that it would take millions of years appears to be pretty good. Someone needs to tell the IDiots that "explosion" refers to the number of new species, not to the speed of their appearance.Marcus Ranumhttp://www.ranum.comnoreply@blogger.comtag:blogger.com,1999:blog-37148773.post-54790753384849469512011-05-24T18:12:04.081-04:002011-05-24T18:12:04.081-04:00If Wells can show an inner contradiction of the th...<i>If Wells can show an inner contradiction of the theory of evolution</i><br /><br />He can't.<br /><br /><i>his own opinion doesn't matter</i><br /><br />LOL! In that case, we can ignore the vast majority of the book, especially the quoted part where he offers his disingenuous opinion as to why Americans reject evolution.<br /><br /><i>He can use every part of the theory against the theory. </i><br /><br />Misrepresentation -- he's using his <i>opinion</i> about part of the theory against the theory.Marcel Kincaidnoreply@blogger.comtag:blogger.com,1999:blog-37148773.post-23776766619429443252011-05-24T18:11:01.313-04:002011-05-24T18:11:01.313-04:00John Harshman says,
A quibble: Jerry Coyne does n...John Harshman says,<br /><br /><i>A quibble: Jerry Coyne does not say that speciation is mostly due to drift.</i><br /><br />I disagree. Read: <a href="http://sandwalk.blogspot.com/2010/12/cause-of-speciation.html" rel="nofollow">The Cause of Speciation</a>.<br /><br />Coyne can speak for himself but I interpret his writing to mean that the actual evolution of reproductive isolation is rarely due to selection, although he's very interested in the rare cases where this seems plausible. <br /><br />It's quite difficult to even imagine situations where geographically isolated populations could undergo selection for the inability to interbreed. The evolution of reproductive isolation is an accident due to fixation of certain alleles by random genetic drift [<a href="http://sandwalk.blogspot.com/2009/02/what-causes-speciation.html" rel="nofollow">What Causes Speciaiton?</a>].<br /><br>Larry Moranhttps://www.blogger.com/profile/05756598746605455848noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-23558731981755580452011-05-24T17:22:20.267-04:002011-05-24T17:22:20.267-04:00In typical eukaryotes, the metabolic cost of DNA r...In typical eukaryotes, the metabolic cost of DNA replication (only occuring periodically prior to cell replication) is then and only then about 2% of the cell's energy budget. Protein synthesis in comparison routinely accounts for ~75% of the cell's energy budget. <br /><br /><a href="http://dx.doi.org/10.1038/nature09486" rel="nofollow">N. Lane and W. Martin, The energetics of genome complexity, Nature 467 (2010)</a><br /><br />This information has previously been pointed out to Bozorgmehr, but he has somehow "forgotten".JohnKnoreply@blogger.comtag:blogger.com,1999:blog-37148773.post-47106253814662213912011-05-24T17:13:17.938-04:002011-05-24T17:13:17.938-04:00Wasn't the big blue box with "Discovery I...Wasn't the big blue box with "Discovery Institute Press", a clue to anyone about what this book was?Profilehttps://www.blogger.com/profile/04497853369536997527noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-55767624474833748222011-05-24T16:56:09.616-04:002011-05-24T16:56:09.616-04:00"most adaptationists are skeptical about the ..."<i>most adaptationists are skeptical about the idea that a huge percentage of our genome is junk</i>"<br /><br />Citation, as they say, needed. Whence do you pull such pronouncements?<br /><br />"<i>You often tilt toward the adaptationist camp so you could serve as a test case. Do you think that more than half of our genome is useless junk that could be dispensed with?</i>"<br /><br />I see Dr. Felsenstein has answered for himself, but as someone who Dr. Moran used to consider a rank 'adaptationist', I'll say: "sure". Evidence: pufferfish.<br />I don't understand why this would surprise you. We adaptationists are not ignorant of molecular evolution, we just don't care much. Phenotypes are a lot more interesting to us.<br /> <br />I am surprised to hear the (unsupported but several-sourced) claim that 'moleculr biologists' might be junk-DNA denialists as a group, though. <br /><br />"<i>If 50% of the genome were really useless, selection would whittle it down, as it has done in countless examples where even something functional imposed too high a metabolic cost on the organism.</i>"<br /><br />Assumes facts not in evidence. The vast majority of a cell's energy budget is spent on ion transport and protein synthesis, and nothing else is evern close.<br /><br />Also, it's worth pointing out as a heuristic that even if large amounts of DNA are functionless junk at the molecular level, its accumulation could still have phenotypic consequences (e.g. cell size, metabolic rate) that could then be subject to selection.Sven DIMilonoreply@blogger.com