The Kinesin Motor: A Stunning Example of Cellular Nanotechnology

_{Jonathan McLatchie

August 15, 2011

Intelligent Design}

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One of the most amazing examples of cellular nanotechnology is a molecular motor protein known as kinesin. Kinesin is responsible for transporting molecular cargo — including chromosomes (e.g. during cell division), neurotransmitters and other important material — along microtubule tracks from one region of the cell to another. Read More>>

Comments

LOL! How did Kinesin evolve again? How many generations to arrive at a novel Kinesin? How many proteins? How many residues? Type slower, I don’t want to miss it.
I love how ID/creationists think this is an argument, when actually it is just an expression of their ignorance. Do you really think kinesin has no relatives? That there is no phylogeny of kinesin sequences and their relatives? Why do you think anyone who is well-informed about the actual science and methods of evolutionary biology should take you at all seriously when you armchair critics won't even bother to get vaguely informed about the most basic data you would need to even begin to have an informed discussion of the evolutionary history of this system. This goes for Jonathan M. also, only ten times more strongly, since he exhibits some actual ability to read science, and yet bizarrely refuses to do any serious investigation of the evolutionary literature and sequence databases which are relevant to even the most basic discussion of the kinds of question he is interested in (or claims to be interested in, at least). Imagine if someone proclaimed the origin of the moon was an unexplainable mystery, without bothering to read any of the literature or look at any of the data on the geology and chemistry of the moon. If you were a scientist who studied moon geology and chemistry, what would you think of such a person? Now you know how evolutionary biologists feel about IDists/creationists virtually every time they write some breezy post along the lines of "X is complicated and functional, and I'm not going to bother to research the evolutionary explanations at all, therefore it's obvious design is the best explanation!"NickMatzke_UD_{August 15, 2011
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LOL! How did Kinesin evolve again? How many generations to arrive at a novel Kinesin? How many proteins? How many residues? Type slower, I don't want to miss it. Cancer! How can evolution be so insensitive? Or is cancer the next phase in our evolutionary progression? Tell me, is it good or bad? Teleology as a crutch? For shame! But not so much as chance and necessity (but aren't they the heroes of our story?). Desperation takes form in the "creative" powers of pitiless, blind indifference. If only chance and necessity would do it's blasted job and explain away teleology!
You haven’t figured out how to think about biology without inserting teleology.
I don't need to. The telic nature of living systems is apparent. Or should I constantly remind myself otherwise?material.infantacy_{August 15, 2011
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"Selected for" what, by what? You don't think "selected for" is teleological? Darwin was a teleologist Mung_{August 15, 2011
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"isn’t this teleological language?" No. "Isn’t evolution a blind process that doesn’t plan ahead for the benefit of the living forms???" Did I mention foresight? Evolution doesn't plan ahead, but when a mutation conferring an advantage (not wasting energy) arises, it will be selected for. This grants the appearance (to some) of design from non-teleological processes. "this sort of mutation would show up, possibly, every four-quadrillion generations" That seems like an awfully large number for a few amino acids in a charged patch, whose only function is to weakly dimerize, given the 10^35 or so cells on earth at any time harboring many mutations each. How did you arrive at it? "As for teleological language, they haven’t figured out how to dispense with it yet." You haven't figured out how to think about biology without inserting teleology. I don't know if it is a crutch, or lack of imagination, but do try harder. Maybe an example like cancer is more in your comfort zone. Complex patterns of mutations are selected for that grant an advantage in growth, migration, immune and drug resistance. These are selected for-cells that lack them are killed off, or outcompeted. You could slam teleology onto the process-saying the cells want to kill the host, or that a designer wills this harm. But adding this teleological explanation is as unnecessary and unsupported (and also somewhat unsettling) as inferring teleology in the kinesin.DrREC_{August 15, 2011
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Yes, but as pointed out above, Enezio, this sort of mutation would show up, possibly, every four-quadrillion generations, or thereabouts; so it is not strictly beyond Darwinian processes to achieve. As for teleological language, they haven't figured out how to dispense with it yet. I think they're waiting on Dawkins to come up with something. xpmaterial.infantacy_{August 15, 2011
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"...a function that prevents the cell from wasting energy..." isn't this teleological language? Isn't evolution a blind process that doesn't plan ahead for the benefit of the living forms???Enezio E. De Almeida Filho_{August 15, 2011
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What numbers would scream for design?material.infantacy_{August 15, 2011
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I'm not sure I'd reach the conclusion that "If this doesn't constitute positive evidence for design, I don't know what does!" Not all Kinesins show auto-inhibition. We can, therefore, ask what would it take to evolve auto-inhibition? The key functional bits in the tail-which allows for auto-inhibition through dimerization, are about 8 residues of an "IAK domain" and some positively charged residues flanking this area. All told, maybe 12/25 amino acids in the tail are conserved and important for function. Additionally, either the IAK or the positive residues show partial inhibition. http://pubs.acs.org/doi/full/10.1021/bi8022575 So we have a function that prevents the cell from wasting energy, that could have evolved in two steps. Neither domain, by any of the calculations denizens of this site are fond of (even taking 20^12) is going to produce numbers that scream for design.DrREC_{August 15, 2011
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