Evolution (or lack thereof) of microtubule polarity from an ancestor lacking polarity

This would be a rather fortuitious event, not much different than a miracle. Thanks for the paper. Like I said, common descent needs miracles to make it work.

variety of chaperones, motors and MT-associated proteins may have coevolved with tubulin and their histories illuminate that of tubulin

Same for this. Co-evolution? Did the dynein MTBD co-evolve too to connect to newly evolved alpha-beta?

LOL! As long as there are gaps in our scientific knowledge Creationists like Sal will be working overtime to cram their God into them. :slightly_smiling_face:

LOL! As long as there are gaps in our scientific knowledge Creationists like Sal will be working overtime to cram their God into them. :slightly_smiling_face:

The issue is the probability of co-evolution of this kind based on accepted principles of statistics, not a gap in knowledge.

Funny, I missed where you provided those probability calculations.

Let us know how your latest “God Of The Gaps” argument from ignorance plays with the scientific community, K?

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Could be? There are. Actin is the most obvious one.

That’s what I suspected, I was hoping you would confirm that since you’re a myosin expert. That response made it worth my time to post this thread. Thanks.

I don’t see how the diagram is relevant to anything you brought up.

Ok, you don’t see the relevance. I agree you don’t see the obvious relevance.

The problem of promiscuous domains is a known problem in evolutionary theory, Evograd student just cited a hypothesis to that effect regarding the charged c-terminal domains of alpha and beta tubulin as if this is mechanistically feasible. I’m not the only one who recognizes this as a problem, but promiscuous domains are promoted as if it were some great scientific discovery of the way evolution works rather than admitting it is not too far from saying common descent needs statistical miracles to make it work. That’s one example.

I like this though I do not fully understand it. Something is really good here because you @stcordova are causing this group to invoke a miracle to start or continue some function of evolution. I find that highly significant because it puts them on a par with a creationist [a place they are loathe to be]. Have you borrowed this from someone? Who can I reference?

Let us know when “Cordova’s Arguments From Personal Incredulity” becomes a recognized field of science.

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Thanks for the paper Steve, that confirms the point I was making even better. If the homomeric form worked in the first place, why should the heteromeric form that involves paralogs evolve?

And thanks to Art for mentioning FtsZ.

This is the heteromeric form creating a microtubule:

There is obvious quaternary structure in the alpha-beta dimer such that we get an orderly pattern in the microtubule. Why should this pattern exist?

The unequivocal identification of microtubules in bacteria throws light on the evolution of modern eukaryotic microtubules from a primordial structure.

Or one could say this is evidence against common descent in that there is a different policy in eukaryotes and prokaryotes for doing similar functions with similar proteins, and the policies can’t evolve one from the other.

Actually it completely invalidated your premise.

You don’t see any difference between the bacterial microtubules and the ones in eukaryotes? And do you believe that if something “works,” then this means that new things can’t evolve? That’s… astonishingly dumb.


Have you borrowed this from someone? Who can I reference?

If I did, I didn’t consciously do so.

I remember once talking to at pre-med Christian Theistic evolutionist. I talked to him for an hour about the evolution of eukaryotes and prokaryotes and what he learned in his classes. I said, “if common descent needs miracles to make evolution work, how is that really different from creationism, except that evolution doesn’t want to admit miracles.” I heard word later he became a creationist that very night after that simple 1 hour conversation.

They call that fitness peaks in evolutionary algorithms, it’s a well known problem.

This is a story worthy of a Jack Chick tract, with you as hero. Thanks for the laugh. I’m assuming you don’t want an answer to your question.


You’re more than welcome for the laughs. I’m glad I can provide some entertainment, but to the matter at hand, Steve Matheson helped me articulate the problem more succinctly, namely, the problem of fitness peaks and how natural selection is in many cases an IMPEDIMENT to evolutionary change, not a mechanism that facilitates it.

The issue at hand is the emergence of functional and integrated paralogs such as the tubulin paralogs in eukaryotes. Co-option of domains and major parts is a necessary but not sufficient condition for the evolution of such functional systems.

By way of analogy, when computer users create pass words, they co-opt the same alphabet as everyone else, the fact of co-option doesn’t make it probable that one user will be able to find a functional password to someone else’s user account. The existence of co-opted parts (as in protein motifs), does not imply functional integration will proceed naturally. Such as in the issue of promiscuous domains, it creates problems for the feasibility of evolution.

I’m assuming you don’t want an answer to your question.

Sure I’ll answer it, there is no fundamental difference, except evolutionary biologists don’t admit their theory needs miracles to make common descent actually work.

They don’t and it’s not.

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However it’s worded it’s a problem, imho, and worth a separate discussion which I hope to explore in another thread. It is very evident in the problem of evolving Eukaryotes from some, presumably simpler prokaryote-like ancestor. But the problem is also relevant in this discussion.

Thank you anyway for your comments, they were helpful.

You’re not humble.

But not worth you actually DOING anything, amirite?

That makes me wonder if you know what “paralog” means. Do you?

No, that’s the wrong answer. In fact I already answered your question, correctly, the last time you asked it. You appear to have ignored me that time, so I’ll repeat: the difference is huge, as separate creation explains nothing, while common descent (even with miracles) explains the nested hierarchy of the data, including the pattern of distribution of those features you consider miraculous. Of course common descent is highly preferable.

Only in a Jack Chick fantasy would your question be a stumper.

No, I went and started the thread since it is relevant to the problem discussed here:

The problem is that if one is going to say the Prokaryotic architecture is “conserved” that would mean selection disfavors slight variations from it. Hence it is the problem of evolving something that is already working under the assumption it is “conserved” for hundreds of millions of years.

This does relate to the problem of evolving structurally polarized microtubules using 3 paralogs of tubulin. But there is a large issue of Natural Selection being inappropriately advertised as facilitating evolution, when it can be said it ought to do a lot of preventing evolution!

The nested hierarchy of data includes taxonomically restricted novel systems not found in other lineages. Thus, common descent doesn’t explain those.

Common descent, for example doesn’t explain membrane bound organelles in Eukaryotic architecture, although all Eukaryotes “nest” under the general category of Eukaryotes.

So the data disagree with your characterization that common descent “explains” the pattern of nesting. At best it “explains” the pattern of nesting for shared systems and proteins/DNA, not the stuff that is not shared!

Common Design Optimized for De-crypting the intricacies of human biology is the better explanation. The supposed evolutionary progression is more like a Rosetta stone for decrypting the structure and function of human biology. So, yes there is a progression, but not one of common descent but of a succession of forms for scientific discovery.