Could you explain how you think that is an answer to my question?
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Sorry, you can’t say “conserved” without accepting common descent within the independent lineages. That means you have to agree that vertebrates share common descent, at a minimum, in order to accept that the protein is conserved in humans. Similarity between separately created groups is not conservation. And of course separate creation doesn’t explain why the similarities among species follow a nested hierarchy.
No, God has nothing to do with the evidence. And you have ignored all attempts to discuss what “parsimonious” means.
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No, conservation doesn’t imply the two genes evolved from a common ancestor. The two genes could have evolved from separate ancestors that would have been endowed at the time with the same pristine prp8 sequence. Under this model, you can have conservation without common descent.
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Your “problem” implicitly assumes the nucleus predates group II intron invasion of the archaeal host genome. Do you have any actual evidence of this chronology?
And your reference shows that there is selectable variation within one mutation that significantly increases function for the intron ribozymes at low Mg2+ concentrations. They literally select mutants that enable greater group II ribozyme function at lower Mg2+ concentrations, with one variant in particular showing 16-fold increase in efficiency with one nucleotide substitution.
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So like, a billion years ago the first universal slime mold ancestor was created with some prp8 protein sequence, and they then subsequently evolved and diverged into all extant slime molds.
A billion years later, roughly, homo sapiens is independently created with a protein sequence that is identical to the one first created in the first universal slime mold ancestor?
How about primates more generally? Which ones share common descent, and were they also created with a prp8 sequence identical to those of the slime mold universal ancestor, and the first humans?
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My point is not to argue for the separate ancestry of slime mold and human. It is much more limited for it only consists in saying that conservation doesn’t necessarily imply common descent. That’s all.
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Perhaps you can answer this question, since Bill cannot:
How do creationists who reject common descent determine whether a gene is conserved?
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Not sure creationists are in the business of determining whether a gene is conserved. Do you have evidences that it is the case?
Anyhow, you don’t have to be a creationist to reject the claim that conservation necessarily implies common descent.
Agreed. Observing that a protein sequence has changed relatively little within two different clades, and therefore also have remained relatively similar, does not of itself imply those two clades share a common ancestor.
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Well, of course, creationists are not in the business of doing any science, as a general rule. However, many of them accept that there are genes that are conserved, and this includes many of those who do not accept common ancestry. Bill has been doing just that throughout this very discussion.
So the question remains: If one rejects common ancestry, how does one demonstrate that a gene is conserved?
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But it does imply that each of those two clades has a common ancestor. The evidence of conservation, as opposed to mere similarity, depends on common ancestry of whatever group you are using to determine that conservation.
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Ah, thanks. I can understand how if each ‘kind’ began at a single starting point, then the ancestral nodes for each ‘kind’ or family should be identical, which would lead to that star pattern. Evidently, that’s not what we see, so the “identical starting point” hypothesis of common design fails leaving only common descent to explain the data.
Hi Andrew
I had a chance to review the star pattern that you were discussing with Rum and John. I don’t think this issue differentiates common descent and common design.
If kinds which may be similar to species can be arranged in a star pattern that pattern is represented on a tree as a single point. The collection of points is what generates a tree.
Here is an example. Humans can generate a star pattern back to Noah, however when you look at a primate tree humans are merely a single point on the pattern.
I hope this makes sense.
Your hope is in vain. You appear not to know what a star tree is, what a tree is, and what data look like.
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That… is undecipherable nonsense, sorry. You seem to not know what a star tree actually is.
Maybe you can show specifically where I am wrong. You can start with a clear definition of a star tree. I was using Rums example that you pointed to for this discussion.
No, it’s hard to get specific with undecipherable nonsense, as it’s all one lump.
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If you had a clear definition of a star pattern generated by created kinds this would not be a hard discussion. Here is Rums description. The only point I made was a pattern on one graph can be a point on another.
Certainly to say that something has been conserved when comparing two extant sequences, is to imply they have changed very little since they each “began”, but does that in and of itself imply they were also more similar to each other in the past? And does that also imply common ancestry?
If two sequences hypothetically began 80% similar say 400 million years ago, and now are 85% similar, then I think one could say both that they have been conserved (as they have only changed very little over those 400 million years), while they also began more different from each other than they are now.
Now of course they haven’t only been conserved in that situation, as they have actually converged towards more similarity than they began with. There are no real-world examples of such sequences of course but it’s possible to speak coherently of conservation even when comparing sequences that hypothetically don’t derive from a common ancestor.
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Correct. But @John_Harshman is right when he notes that conservation implies a lineage, ie implies that a given sequence within an extant species was transmitted from an ancestor to the extant species through reproduction.
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I can try:
What do you mean by this? The genetic data from humans do not generate a star pattern, but a nested hierarchy. Even if we descended from a MRCA as recently as Noah (which is impossible, as @swamidass’s TMR10A calculations show, unless you place Noah as early as 180 kya), this would still be the case. This is why I think you don’t understand what a star tree is.
I think you are referring to the fact that, on primate phylogenies, humans are typically represented as a single branch. But this has nothing to do with humans supposedly forming a star tree back to Noah, and it doesn’t change the fact that if all ‘kinds’ were created with identical genes, they would form a star tree (which we do not see).
Yes, @Rumraket defined it very well as a “tree rooted in a giant polytomy.” But the human tree is not rooted in a polytomy (see the Y-chromosome tree below), so we evidently do not form a star tree back to Noah. Do you know what a polytomy is?
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