Is convergent evolution evidence against common descent?

Let's say that the above molecular data is giving the correct picture. This lineage has been separate from both the placental line and the marsupial line for a very long time. With that long separation we would expect a lot of trouble trying to fit it in with the existing lineages. There was no fossil evidence and the morphological evidence was something that individuals could argue over. I'd have to see if the majority of the experts held "bizarre" views or if it was individuals making such choices to see how great the confusion was.So what? You again are jumping on outliers without any answer for the overall pattern. In this case the molecular data suggests that these animals were very separate from others. The attempts to fit them with others caused a lot of problems. Makes sense doesn't it?How many anatomists speculated on it's affinities with the placental mole and why did they do that? If only one how many other disagreed? Science is mostly a consensus enterprise. Is it possible that the golden moles and the marsupial moles have both been separated for a long time and may even be closer relatives to each other than to others? (I doubt that but we don't have enough evidence right how.)This apparent odd ball doesn't mean the other issues are not there?You are asking questions are aren't answering any?

Ned, the claim I am not answering any questions is BS, on your part.The simple fact is that you seem continually to be trying to get away from the data and back to the Big Picture assertions, and frankly it does not help your case.In this area, there are a couple of obvious relevant points:1. The genetic data we are seeing from our own little research does not match these claims. I don't know what that means, and apparently you don't either, but at least I am not pretending to know why our data runs don't match this.2. The fact that some credible anatomists considered classifying this mole with a placental mole is a testament that this Marsupial/Placental pair shares remarkable similarities just as I have said all along, and you seem loathe to admit.I admit that the data we looked at thus far supported your prediction, but you won't admit to the anatomically similarities, not in type, frequency, etc,...Why is that?

from Message 250 - emphasis added The whole point is that convergence produces just such similarities but not other types. Thus we can see a difference between the convergence cases and not non-convergence cases.There are then some cases that are not so clear cut. That doesn't obliterate the many cases that are very clear cut. You don't seem to want to recognize that. I think you had better clarify must what "these claims" are exaclty and just which data runs do and which data runs do not match those claims. I don't see it the way you do and would like to make sure we are talking about the same things.

The data seems to indicate similar relatedness between all of the marsupials, but the article indicates the marsupial moles as farther apart molecularly, and thus a "distinct line."Btw, can you think of any one trait that could not evolve via convergent evolution?

When I brought up a 1998 genetic study you called it outdated. Now you are bringing up a 20 year old genetic study and 19th century anatomists? All that the study suggests is that marsupial moles appear to have diverged from other marsupials about 50million years ago.That still places them closer to other marupials than other placental moles, doesn't it? I'd actually be interested to see what anatomists were saying just prior to the molecular data, rather than 100 years before it.

randman, Clearly contradicted by the fact that that they do match more than we would expect. Check any of the phylogenies that have been presented here. There is a broad agreement with the morphologically derived expectation. The data here exactly matches the morphological expectation. That's three 8 taxa phylogenies, 135,135^2:1. 18,261,468,225:1 I don't call that being molecular data not reflecting morphological data, do you? The data may become more ambiguous towards the terminal nodes of any given "recent" cladogram, which is likely the complaint here. Or on data where divegences are extremely old where "noise" is more likely to mask signal, but the overall pattern is still way, way more congruent than we have any reason to expect.Do you have 18 billion cladograms with no congruence to render the three conclusions statistically insignificant?The nature of the evidence isn't that a "mere" 50% congruence, & therefore a 50% incongruence represents ambiguous results. The sheer number of potential trees means a congruence is an unlikely event & therefore a likely signal.MarkThis message has been edited by mark24, 06-10-2005 03:18 AMThis message has been edited by mark24, 06-10-2005 04:07 AM

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There are 10 kinds of people in this world; those that understand binary, & those that don't

randman, That the marsupial moles diverged from other marsupials relatively early is neither here nor there. Something has to diverge earlier than other groups within the same taxon, & by definition will form a "distinct line". In the same way the suiformes & cetacea diverged from other lineages within artiodactyla & formed "distinct" lineages.MarkThis message has been edited by mark24, 06-10-2005 07:50 AMThis message has been edited by mark24, 06-10-2005 07:53 AM

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There are 10 kinds of people in this world; those that understand binary, & those that don't

Yes, while one could argue that anything can reevolve (e.g., eyes, over and over) what happens in the real world is there will be easier, more available pathways that will divert the evolutionary direction.It all depends on where you start and how closely you define "one trait" as contrasted to "similar traits". A rat could evolve wings but will not evolve feathered wings. A squirrel may evolve grub digging capabilities but will not evolve a jack-hammer woodpecker like solution.ABE
An otter will not evolve gills.This message has been edited by NosyNed, 06-10-2005 12:56 PM

Mark, that's BS and I am calling you on it. Take the whale evolution and hippo. They changed the cladograms to match after they obtained the molecular evidence, not before, and that's the point. They didn't match. Sure, you can get them to match, after the fact.Also, on the other post, you are dodging the point, again. The point on the moles is our data, which are touting here so highly, indicated moles are more related to the other marsupials than the expert's data.Maybe just testing a few potein sequences is not sufficiently comrehensive to draw conclusions, and statistical analysis from, as you are fond of doing here.

You guys are hopeless as far as staying on topic. Let's deal with the facts, please, one at a time. That's because I brought up studies to show what people thought the anatomy showed prior to molecular testing.Duh!You were arguing present knowledge, and thus were out of date. I had to find older quotes to make my point, and this hits on something evolutionists do all the time, which is deceptive, imo.They argue from present knowledge very dogmatically, but never admit where they argued the opposite line of logic in times before. It always boils down to arguing the conclusion first. It reminds me of politics where someone like Clarence Thomas is attacked for reportedly making lewd comments to a co-worker, but the same people defend Bill Clinton for flouting sexual harassment rules.That's one reason I don't think people should consider evolutionists and evolutionism necessarily as very credible. They don't seem to own up to their past mistakes, in the logic, and always seem to overstate their case. It's a present and believe the conclusion first, and then spin the facts to make them fit later type of game, and to me, that's not real science.

Mark, let me clue you in to where you are being deceptive or ignorant of the history of the theories of hypthoses of whale evolution. The DNA did not match, but forced changes in what people thought.Before the 90s, the prevailing view was whales evolved from Mesonychia.Page not found – BiologyDaily.com Just a moment...The truth is the DNA did not match the anatomy. Then, what happened is that they say the whales came from Artiodactyla and specifically from ruminants. Hippos were not considered closer to whales.Then, via DNA testing, they now claim Hippos are closer to whales than whales are to other Artiodactyla.Now, if you want to still maintain they considered the morphological and anatomical and fossil evidence had always put the Hippo and whales together, you can, but you are just fooling yourself.The evidence does not support you, and I would argue that the main reason scientists argue for one hypothesis or another is that they so based on the idea that the whale had to evolve from a common ancestor of one of these sources.If you take that assumption out, and view the data for what it really says, the truth is we don't have that much evidence that whales evolved from land animals, or evolved at all from anything other than a whale.The only way you get that is to go back the big picture, and insist that everything had to evolve from a common ancestor, and then you start skewing evidence to make that fit.This is why I think you should look at the details first, and see what they independently support instead of simply assuming common descent and claiming everything fits when it doesn't it.Did whales evolve from non-whales? Maybe, or maybe not. Imo, that's what the data really shows.This message has been edited by randman, 06-10-2005 01:55 PM

Wow - you kind of missed my point, and concentrated on a jolt of humour. Perhaps I should restate my actual point, which was on topic:

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That still places them closer to other marupials than other placental moles, doesn't it?

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If I'm following the thread rightly here, placental and marsupial moles, was what we were talking about.I'll say another thing again:

quote:

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I'd actually be interested to see what anatomists were saying just prior to the molecular data, rather than 100 years before it.

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That is to say, a modern anatomist who didn't have the benefit of genetic comparisons. I would be interested to see if they thought that "it had it closest affinities with the (placental) golden moles".Let's imagine our modern anatomist examines the marsupial mole and finds (to paraphrase from Message 239)The braincase is small and narrow. It houses a relatively small and simple brain compared to that of similar-sized placentals.
The jugal is large, extending posteriorally so that it actually contacts and forms part of the glenoid fossa.
The lacrimal canal is slightly anterior to the orbit so that it opens on the surface of the face rather than inside the orbital space.
The bullae are sometimes not ossified, and when they are, they are formed largely by extensions from the alisphenoid.Would they consider that more closely related to a placental mole or a wombat?Your counter to this is that over a century ago an anotomist initially couldn't find the epipubic bone (I assume then, that he eventually found it, and speculation wasn't so rife?). Whereas my one sentence and one question were mildly off topic - this entire rant is totally off topic. We are talking convergent evolution, currently revolving around marsupial and placental mammals. Is it me or is going off topic with wild generalisations about the debating tactics of your opponents, the comparisons it has to politics, dogma and exagerating about exageration, a tad ironic? Don't answer of course, it would be off topic (unless you want to be really ironic...haha)

The comments on the link I provided refer to more than 100 years ago, and verify my overall point, that DNA studies often differ from anatomical studies.Imo, the fact you guys even argue this is indeed evidence of a political mind-set. No one denies this in the literature. Global Industry Market Sizing - NationMasterYour claim that all modern anatomists would agree with the DNA evidence even if that was not available is entirely bogus.As far as the Marsupial/Placental discussion, you fail to realize that the evidence supports my point in the OP, regardless of which way it falls out. If the evidence fully backs convergency without more similar DNA to more similar form, that supports the idea that similar traits, and highly similar creatures can evolve without common ancestry, assuming they evolved at all convergently.If the DNA evidence supports, say, a marsupial mole being more similar to a placental mole, that would be even stronger evidence, I admit, against common descent, and that does not seem to be the case.

Care to tell me how you know that, given that you have absoloutely no idea what this 'data' you are referencing actually is?I'm also not sure quite why you think this is relevant to any of the alignments people have been doing here, since none of them have Notoryctes in them, unless I've missed some. Which data exactly are you trying to compare this 'data' of yours to?TTFN,WK

You showed me the opinion of an anatomist who couldn't find a bone. Had he found the bone, what would his opinion on the marsupial mole have been? Did he find the bone? When was the bone discovered? What happened when it was discovered? All you are really showing here, is that without full data, an anatomist might find it difficult to classify a creature. I made no such claim. I actually asked a question, and even if you rephrase my question into a claim, I didn't make the claim. Let's look at what I said: You're right, nobody is denying that marsupial moles diverged from other marsupials 50 million years ago. I'm quite happy to accept that fact for the time being. Now - does that make it closer to the wombat or to the placental mole? We've already agreed that the marsupial/placental split (if it happened, which of course is what we're debating) was probably somewhere in the region of 150 million years ago , so I think the conclusion is fairly apparent.This message has been edited by Modulous, Fri, 10-June-2005 07:25 PMThis message has been edited by Modulous, Fri, 10-June-2005 07:27 PM