Is convergent evolution evidence against common descent?

All that and still ignoring the point.Why not admit openly that DNA evidence has caused shifts in the way we think things evolved?You have to try to continually divert the OP topic because you don't want to deal with the evidence.What you fail to realize is empirical analysis should mean one analyizes the details and assumptions on how data is viewed so that we can see if the conclusions, which you are so fond of posting, are correct.That's the thread topic here, to look at the details of the assumptions on how data is viewed.You are simply trying to dodge the facts and making factual errors in the process.I will respond to the ear evolutuon question on a separate post.

I am glad you responded to the ear comment because it deals with the OP and at last someone wants to get into the specifics of that. But you are mistaken here. The current idea is that the 3 bones did not evolve prior to the divergence. PLEASE! Learn how to insert links. Just a reminder from your still friendly AdminThere is some additional discussion below that may be helpful. This refutes, by the way, the idea on another thread and this one as well, that surface traits such as a streamlined body for fish are what convergency can account for, but not such interiour forms that presumably are subject to less selective pressure. http://www.ccebh.umd.edu/comparativehearing.asp So here we have strong evidence, that based on common descent assumptions, that even tiny ear bones can evolve indepedently. I think this one piece of evidence alone calls for seriously looking at assumptions of what convergent evolution can account for, and also whether there are other commonalities to explain the seemingly very improbable event of something like the ear bones emerging independently. That to me suggests that there be other mechanisms at work besides random natural selection.Moreover, it suggests that details between creatures such as the hypthesized and famous reptile and mammal transitions are probably overstating the fossil evidence by claiming similarities point to common ancestry when that clearly is not the only answer.Ear-splitting discovery rocks mammal identity | NatureThis message has been edited by randman, 06-10-2005 03:51 PMThis message has been edited by AdminJar, 06-10-2005 03:03 PM

Let's test your statistical analysis claims. You wrote: Based on your methodology, what would be the statistical likelihood of the 3 ear bones independently evolving in the different mammal groups? Please consider as if we do not already know the answer.Imo, this ia good test for your claims. I suspect that you would have argued that it was statistically nearly impossible for the 3 ear drums to independently evolve.I would agree with you if that was the case, which suggests to me a rethinking of the process, either of the methods producing evolution, or the actual form of evolution itself.Do you think that's an unreasonable idea?This message has been edited by randman, 06-10-2005 03:57 PM

This is the problem. You guys are trying to make this thread about the concept of common descent overall whereas I am restricting it to a narrow focus which how should the discoveries of convergent evolution affect common descent models, and yes, the data supporting the theory overall.Specifically, there is often for example statistical analysis thrown out based on an assumption of randomness along with a ton of other assumptions.I would submit that adopting these assumptions makes such events like the convergent evolution of the ear bones in mammals to be a near statistical impossibility.So either it did not happen that way, or some of the assumptions are wrong, imo. I am open to a myriad of possibilities.Some could be that common descent occurred but that it is not random, that there is evidence of some sort of guidance going on to cause such improbabilities. If you restrict the discussion to mammals, it seems like this is a strong argument.Another possibility is we are misreading the data by always trying to assume universal common descent.My point is our assumptions whereby we view the data seem to be incorrect, and by determing what those assumptions are, whether some are likely to be wrong, etc,....could help better understand what really happened instead of what I see is somewhat artificially imposed arguments to dismiss all commonalities besides common descent.I think it is fruitless to argue for one hypothesis for how it happened over another until we determine and analyze the underlying assumptions on how we view the data.Let's take an assumption of one, single linear progression of events through time. Seems logical, but in physics, there are some that seriously contend that reality consists of a multi-verse and our version of reality is just one "verse" so to speak. Well, and this is just for illustration not to debate here, but what if there is some bleedover in the multiverse so that parts of one universe get mixed in with another. That would explain some of this fairly well, imo, but then again, it is far too speculative to know the answer on that.But we should know that our assumption by which we view the evidence is based on a linear presumption of a single universe, and that the present and future do not have a causal effect on the past.This message has been edited by randman, 06-10-2005 04:11 PM

This is so typical of overstatements in your camp, that it is good indication of what I am talking about. I could just as easily claim that the independent appearance of the 3 ear bones falsifies the theory of common descent, completely, and be just as correct.1. We have not done, nor seen, comprehensive genetic exams to prove one way or another. As I stated, it only takes one example, one anamoly, to verify my prediction.2. But even if there is not one, it still does nothing to alter the concepts of the OP. It clarifies that similar forms may not be the result of DNA. That's a good thing, although that is not a proven yet. You fail to realize that some clarification here does nothing to disprove the overall point. It helps my case in some respects, but may prove my hunch wrong as far as the genetic sequencing issue goes.3. Btw, I am glad we went over this evidence, but I said repeatedly, that either way the evidence came out on this, it was still problematic for common descent anlysis, and I stick by that. In fact, if the current theory of evolution for marsupials and mammals is 100% true, it still verifies the point I am making. I don't think you realize that. It has not been shown at all that niches and environments are the sole means of driving evolutionary change. You guys have merely asserted that, but offered no proof. In fact, convergent DNA indicates that you are wrong. In fact, we see convergency with non-coding DNA when there is by definition no exteriour environmental pressure or niche at play whatsoever.If anything, the genetic evidence we have gone over thus far proves my point. It shows convergency is a powerful factor in creating similarities.Moreover, no one has shown convergent evolution only creates superficial similarities.Can you name how the ear bones are superficial?Are they superficial in function, form, or exactly what?You are just 100% wrong here. Not sure what you refer to here. If you refer to the dolphin that can mate with the false killer whale, you do realize that is considered evidence of common ancestry not convergent evolution?This message has been edited by randman, 06-10-2005 05:07 PMThis message has been edited by randman, 06-10-2005 05:33 PM

Maybe you clarify a little for me? Odds against what? Are you claiming the odds of these matching for any other reason than common descent via random mutation and natural selection is 135,135:1? Why should we accept these odds here? It says nothing about the mechanisms involved, even if the cladistic are accurate. I don't see it. These are odds based on the assumption of randomness. Imo, that's a false assumption.Take the ear example to illustrate my point. Common descent/ancestry predicted that as well, and it has been claimed that such depth of identical traits has to be common descent, that there is no other explanation, etc, etc, etc,...But now, we see, whoa, there is another explanation, and that is convergent evolution can create the appearance of common descent in extremely detailed functional, non-surface traits.The fact cladistics may be supported, as you claim, for mammals, with significant adjustments as I have pointed out, does not negate the point that when we look at fossil evidence without such detailed genetic data, that we could be interpreting the evidence wrong.To leap from common ancestry for mammals to universal common descent is an overstatement. Moreover, there is considerable continuing research on the genetics. Showing 8 phyologenies, etc,..as was shown here is not near enough to even validate the claim on the mammals.Your claim that the odds of the taxa lining up are such and such, at least as far as I can tell, do not come with the necessary corresponding analysis of what else could explain similar genetic details, and the fact that taxa could be correct, in linking groups of animals together, does not prove the evolution from one taxa to another.Keep in mind that one thing being more likely than another is not conclusive evidence it happened. If that were the case, the ear bones could not have evolved independently. Well now, I didn't realize that. You've opened a door big enough to drive a truck through. If these are not related to morphological functions, are they the result of selective pressure? I suspect matebolic functions are subject to selective pressure.If so, then such similarities can be explained via convergent evolution.If not, they can be explained via convergent DNA.Either way, common descent is not the only answer. Why not? Moreover, it is not exactly the same as the morphologically derived tree. You want to dispute that, but the fact molecular studies change the trees which were once just based on anatomy proves my case.What if the mechanisms for causing convergence in the DNA, that you say is not related to morphology, also affects morphology and creates similarity there?First, I am not convinced that your claim that these play no role in morphology is true. Maybe you are right, but it could well be there presence helps to give certain DNA sequences a predisposition towards certain forms, and if that is the case,then we see inherent within the chemical properties a design mechanism that helps create a duplication in forms, which incidentally matches the evidence.I am not convinced that the duplication in designs is the result of only random mutations and natural selection since that suggests these forms are the best solution since they tend to come up over and over again, but as many point out, there are flaws in these solutions.What you are claiming suggests that the only reason the ear evolved independently is because that's the only effective solution there could be. I don't but that.That to me is obvious evidence of some other mechanism besides mere random mutation and environmental pressures, especially since even the niche and similar environment claims are unproven and contrary at times to the evidence. One can always imagine a way around it, and that's what it takes, a whole lot of imagination for extremely implausible scenarios.

Sure Mark, after you calculate the odds as I asked you, of the chances of the ear bones independently evolving from chance, mutations and natural selection.Please be specific.

Mark, cladograms based on CytoC alone do not provide identical cladograms as other molecular and morphological data. I ran a search and comparison for:human
kangaroo
horse
rattlesnake
turtle This has a kangaroo very closely related to the turtle (88), and fairly close to the rattlesnake (73.5), and more so than to humans, another mammal, (20.582), and that the kangaroo more closely related to the turtle than the 2 reptiles are to each other.Maybe I made a mistake, but this does not match at all.Moreover, it is common knowledge there is significant debate between morphologists and molecular systemists in which data is correct.You need to own up to that and quit pretending there is no debate on this issue.This message has been edited by randman, 06-11-2005 02:16 AMThis message has been edited by randman, 06-11-2005 02:18 AM

see corrected post on CytoB 2 posts down.Edited this one out due to incorrect name and error as Mondulous figured out. Thanks Modulous.This message has been edited by randman, 06-11-2005 03:40 AM

It looks like the site will give you wrong data for common names. I looked up and ran the scientific names though, and got the following. Please note that "alligator" is alligator snapping turtle, aka Macroclemys temminckii.Maybe this has an error too, but it definitely does not correspond to current cladograms. Humans are more related to alligator snapping turtles than a red kangaroo, aka Macropus rufus, according to this?This message has been edited by randman, 06-11-2005 03:42 AM

WK, how about comparing the genomes of a opossum, human, kangaroo, mouse, and turtle?I don't really know of a placental couterpart to the opossum, but seeing the data on these, if done, might shed some light on the process. Or, pick some others. Basically, whatever is available, but the fact humans are probably available, and the opossum as your post indicates. It ought to be informative to see how some others come out that are somewhat in-between.The turtle is just to throw a curve in there and see what happens.

Markm first off, your stance that molecular evidence all supports morphological "trees" is untenable. There is no debate on that.On the data you showed, that shows very little. Heck, I just ran some data on the same program for CytoC and CytoB and got totally different results from what your scenario predicted.So the short answer is that your questions are wrong because your data is wrong. First off, what do you mean by "seems so inevitable to you"?Secondly, I hear you claiming that the morphological analysis agrees with the molecular analysis that place the cetaceans and hippos as one monophyletic group, and that's where you are wrong.The morphologists disagreed with the molecular systemists. I don't know why you don't just up and admit this. You continually base your entire argument and participation in this thread on a factual error on your part, falsely claiming the morphology and the molecular data agree here on whale evolution when they do not.It is unbeleivable to me that after all these posts, you still ignore the debate between morphologists and molecular systemists, and erroneously claim they have always been in agreement in this matter.This message has been edited by randman, 06-11-2005 04:19 AM

They don't. I don't see why you don't get it. Anyone can draw a cladogram after the fact to match the molecular data, and that's what molecular systemists do.That doesn't make it congruent with the morphological data. But don't take my word for it. Read the following: Taylor and Francis reference
(edited by AM to reduce reference length)http://diglib1.amnh.org/novitates/i0003-0082-344-01-0001.pdf Just a moment...This message has been edited by randman, 06-11-2005 04:29 AMThis message has been edited by AdminNosy, 06-11-2005 09:53 AM

Read my edits above.Also, I am not ignoring that fact. That's the whole point. The morpholigical data and trees disagree with the molecular, and the molecular has caused a revision in the data.Maybe we are talking past one another. You claim to have run some data that produced a cladogram that matched the current phyologenies, probably of a molecular systemist.Well, duh! He's already run that data and used it to advance his cladogram. That's why they matched 100%.But that doesn't mean it matches the morphological data.There is no amazing statistical fact here. You ran molecular data and compared the results with those that ran the same data with the same results. No wonder it was 100%!Also, I did post the data. Read the thread and the new thread.But rereading your post, I see where you are admitting that there are changes in the clades, that disagreement between molecular and morphological systamists is indeed real. Good.As as why CytoC and NADH should parrallel one another, it could be something related to how they interact within the DNA. From what I can tell, all of the molecular data does not fit as nicely as those 2 did on your data. Why not look a little more deeply?This message has been edited by randman, 06-11-2005 04:35 AMThis message has been edited by randman, 06-11-2005 04:53 AM

WK, why only around 50% for the same species? That doesn't make sense. I know you said take it with a grain of salt, so to speak, but that's more like a whole block of salt there.Shouldn't it be near 100%?