Evolution and Auxotrophy

The owner of this website: http://www.tetraheed.net/ has posted a set of three essays on evolution and religion. Part 1 is quite well written. I have some problems with part 2. Part 2 is found here: http://www.tetraheed.net/rel-dar-2.htm
Here is an excerpt:

Why did all mobile animals become auxotrophic (a term that is explained below), when auxotrophy was clearly against the best interest of any species?
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It baffles me that evolutionary scientists have never faced up squarely to that question. Unless people such as Dawkins and Provine can answer these questions, they should reconsider some of their published claims and public statements, claiming to know the answers confidently and even absolutely.

My undocumented position is that evolutionary scientists have indeed faced up to this and have presented clear and logical explanations. These explanations may not have directly answered the question, but the question is answered and the premise of the statement is wrong.I encapsulate and simplify the explanation by saying that when the ability to manufacture a vitamin or amino acid was lost, that substance was being ingested by other means such as eating plants and other animals containing that substance. The lost was not intentional or guided; it was a random occurrence that simply had no effect. The animal (species) carrying this genetic code that lacked his ability suffered no disadvantage in the competition called life. Eventually the auxotrophic genome became a part of the species.So the explanation is clear and simple. At least in my mind. What do you say?

Has anyone read my post? Is there something wrong with it?

Thread moved here from the Proposed New Topics forum.

I see what you mean about having some problems with part two.
This definition struck me as a little hard to defend: here's a
biochemical definition: vitamins are organic molecules
that animals need but cannot synthesize, in their own
bodies, even if they are completely healthy, and have a
full and normal set of properly functioning genes.Unless he's redefining 'vitamin' in a unique way, he's just plain wrong.

I went to Ask.com - What's Your Question? with "define vitamin" and selected two definitions:noun: any of a group of organic substances essential in small quantities to normal metabolismVitamins Definition: Vitamin are a group of substances essential for normal metabolism, growth and development, and regulation of cell functionHe threw a little bit extra in there, but a) If we could generate the molecules we would not need to get them ready made and we would not think of them as vitamins and b) that's not the point of my question.He is fundamentally correct about vitamins, if overly exuberant. The question is: He claims that since we have lost the ability to construct multiple vitamins, this loss could not be the results of evolution as postulated by the theory of evolution (TOE). I say it is valid. He uses this as an example to support his belief in a god. I say that even if his declaration is true and that even if the TOE could not justify auxotrophy, it would still not no be a valid argument for god. An error on one theory does not imply that an another theory is right.Summary: I ask if you agree on two points:1) Do you agree or disagree that the TOE supports auxotropy as I claim it does and he opposes?
2) Do you agree or disagree that the alleged defect in the TOE really has no bearing on his argument for a god?And of course, Why?Thank you.

quote:

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1) Do you agree or disagree that the TOE supports auxotropy as I claim it does and he opposes?

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I agree. I don't see the question as fundamentally different from asking why cave-dwelling creatures lost their vision, or why some birds became flightless.

quote:

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I encapsulate and simplify the explanation by saying that when the ability to manufacture a vitamin or amino acid was lost, that substance was being ingested by other means such as eating plants and other animals containing that substance. The lost was not intentional or guided; it was a random occurrence that simply had no effect.

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I don't completely agree with that. What I find missing from that explanation is that these evidence an economy of developmental resources. Every design process encounters conflicts between counteracting principles, and every design represents some concessions; you can't have it all. Just as equipping lighter-than-air vehicles with heavy armor isn't a viable solution to a serious drawback inherent in employing them as military platforms, producing every needed substance in-house may not always be the most practical approach for every organism. Many organisms manage to get by without the capability to perform photosynthesis; why doesn't he complain about that?He also makes a somewhat dubious assumption here:"Higher animals didn't start out as auxotrophs; the lower forms of life, from which higher animals evolved, don't need vitamins or essential amino or fatty acids."That may well be true, but I don't see the basis for stating it with so much confidence; we don't know squat about the 'lower forms' from which 'higher animals' evolved.

quote:

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2) Do you agree or disagree that the alleged defect in the TOE really has no bearing on his argument for a god?

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I agree. I didn't have cereal for breakfast, but that doesn't automatically mean I had pancakes.

That’s a bit finicky isn’t it? I mean you can synthesise some vitamins from pro-vitamins but the point is you can’t make them from scratch and you need to get them from your diet in order to be healthyThis message has been edited by biochem_geek, 09-11-2005 10:13 AM

Then he labours under the commonly held misconception that all every single feature of an organism must have a sectective advantage. Sometimes traits that are either selectively neutral or even slightly deleterious end up becoming widespread. Especially in small populationsYou can google for “genetic drift” or the “the neutral theory” if you want a deep understanding of how that works. But they are basically what you described earlier, a couple of examples1)
You, me and all the other primates have a gene for making vitamin C which is broken. So, at some time in our evolutionary history one of our ancestors picked up a mutation that rendered a ”good’ vitC gene useless. Most primates eat loads of fruit which probably meant that the loss of vitC gene wasn’t all that much of a drama and there was little or now pressure keep it. An in fact, that mutation spread in the population to such a point that all the descendants of this ancestor have the broken copy of the vitC gene.2)
We can actually see the evolution of auxotrophy in parasites. Some parasites like the bacterium that gives rise to leprosy live inside their host’s cells. In this environment the parasites have all the stuff they need to get and there is no pressure for them to synthesise their own chemicals. As a result their genes ”rot’ and the lose most of those functions. Here’s a light article about ”reductive evoluton’This message has been edited by biochem_geek, 09-11-2005 10:12 AMThis message has been edited by biochem_geek, 09-12-2005 01:24 AM