Intelligent Design

Just say NO to Darwinian just-so stories

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[From a biologist colleague:] Ross and Pawlina’s histology textbook (2006; ISBN 0781750563) demonstrates a remarkable ignorance of genetics (it’s otherwise a good text) in its discussion of the parietal cells in the stomach (which are the cells that make hydrochloric acid):

“Recently, it has been hypothesized that parietal cells may have originated from a bacterium called Neurospora crassa (TJ: it’s actually a fungus) that previously existed in a symbiotic relationship with the cells of the human stomach. The basis for this hypothesis is that the human proton pump (H+/K+ ATPas) found in parietal cells bears a strong genetic similarity to proton pumps found in this bacterium. The bacterial DNA is thought to have been translocated and subsequently incorporated into the nucleus of the stem cells, probably with the help of a virus.”

This seemed awfully bizarre, so I found the abstract for the original article, pasted below. Such a scenario seems to be impossible. It’s one thing for a microorganism to exist in a symbiotic relationship with the host organism. However, for such a horizontal gene transfer to take place, the DNA would have to be transferred to the gonads if the gene would be passed along to subsequent generations.

I guess that’s what happens when you assume that sequence similarity automatically means a common ancestry (of the gene). A more likely scenario is that both cells require a protein with the same function so they have a similar sequence by design.

Once again, an ID perspective seems much closer to reality than the Darwinian (Lamarckian?) just-so stories.

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J Clin Gastroenterol. 1997;25 Suppl 1:S141-8
Hypothesis–origin of the parietal cell: microorganism?
Okabe S.
Department of Applied Pharmacology, Kyoto Pharmaceutical University, Japan.

ABSTRACT: Parietal cells, which exist in the stomach and in Meckel’s diverticulum of the ileum, secrete hydrochloric acid by means of H+,K(+)-ATPase (alpha- and beta-subunits) in the human body. Although parietal cells are generated from progenitor cells (stem cells), their lifespan (approximately 150-200 days) is dis tinctly longer than that of surface epithelial cells (4 days), which are also derived from stem cells. Microorganisms, including bacteria (both aerobic and anaerobic), are able to pump H+ out by means of H(+)-ATPase. Of interest is that 19% of the human H+,K(+)-ATPase (alpha-subunit) comprises amino acid residues identical to those of the H(+)-ATPase found in Neurospora crassa. In addition, the amino acid sequence in the ATP binding sites of animal Na+,K(+)-ATPase and yeast H(+)-ATPase with phosphorylated intermediates is highly conserved. These data appear to indicate that the parietal cell might have originated from a microorganism that was parabiosed in a separate origin, having digestive organs, that was later incorporated into a stem cell. Thereafter, the gene encoding H+,K(+)-ATPase, or those encoding GATA DNA binding proteins (transcriptional regulators of the gastric H+,K(+)-ATPase gene), or both were translocated into the nuclei, most probably with the aid of a viru s and/or a transposon under unusual circumstances. This type of gene translocation most probably occurred during the Cambrian era when Prochordata and Chordata, which have no parietal cells, were abundant. This suggests that in the process of evolution, the stem cells in the digestive organs of the Cordata might have differentiated into two cell types, i.e., surface epithelial cells and parietal cells, before the appearance of fish (which possess parietal cells with H+,K(+)-ATPase).

8 Replies to “Just say NO to Darwinian just-so stories

  1. 1
    DaveScot says:

    What’s more amazing than horizontal gene transfer under mysterious circumstances is the fact that the DNA in the yeast cell and the human stomach cell both use a compatible codebook and protein factory which makes horizontal gene transfer possible in the first place. These similartities in protein manufacturing machinery and the program code that runs the factory aren’t just 19% identical between yeast and human. They are so close to 100% identical it boggles the mind. The core components of every living cell are virtually identical. Sometimes you can’t just say no to the implications. Human and yeast cells either have a common ancestor or a common template was used to design both of them. The deep relationship is the same either way so I’m not sure it makes much difference how the relationship was established. The two cell types are still deeply related.

  2. 2
    John Davison says:

    Of course common templates are the answer just as the PEH predicts. I thought everybody knew that by now. (ha ha).

  3. 3
    hugh williams says:

    Hello everyone, this morning I received an email from “Medical News Today”, that may be of some interest here. The title, “Drug Resitance May Travel The Same Path As Quorum Sensing”. This pertains to a Baylor College of Medicine study, on the mechanism of drug resistance in bacteria.

    http://www.medicalnewstoday.co.....wsid=37257

  4. 4
    Red Reader says:

    From the post of Dr. Dembski’s colleague:
    “I guess that’s what happens when you assume that sequence similarity automatically means a common ancestry (of the gene).”

    Assumption. Extrapolation. Flat earth.
    “The earth I see is flat. Therefore the earth I don’t see is flat.”

    Scientific…NOT.

  5. 5
    John Davison says:

    Common ancestry is an appealing idea with very little to support it. Nevertheless, whenever life was created and no matter how many times that was done, its subsequent history was predetermined from that point on. Currently I see at least a half dozen separate creations but what do I know?

  6. 6
    Joseph says:

    Once we understand what makes an organism what it is* we will have a better grasp on the number John D now has @ “at least a half dozen”.

    And John’s “predetermined” status is akin to: John R. Koza, Keane M A, Streeter MJ; “Evolving Inventions”, Scientific American 52-59 Feb 2003, in which previously determined “inventions” were allowed to “evolve”. (allowed meaning everything was set up- the program, the resources, etc., for success.)

    *What makes a fly a fly? In his book (English title) “Why is a Fly not a Horse?”, the prominent Italian geneticist Giuseppe Sermonti, tells us the following :

    Chapter VI “Why is a Fly not a horse?” (same as the book’s title)

    ”The scientist enjoys a privilege denied the theologian. To any question, even one central to his theories, he may reply “I’m sorry but I do not know.” This is the only honest answer to the question posed by the title of this chapter. We are fully aware of what makes a flower red rather than white, what it is that prevents a dwarf from growing taller, or what goes wrong in a paraplegic or a thalassemic. But the mystery of species eludes us, and we have made no progress beyond what we already have long known, namely, that a kitty is born because its mother was a she-cat that mated with a tom, and that a fly emerges as a fly larva from a fly egg.”

  7. 7
    John Davison says:

    Giuseppe Sermonti is a wonderful man who has been kind enough to publish several of my papers even though I am sure he does not agree with everything I say. Such editors are rare birds and I will always be indebted to him. His little book is charming and I recommend all read it. It constitutes one more devastating commentary on the Darwinian fairy tale from a kind and gentle spirit.

  8. 8
    irees says:

    Found this page randomly, but couldn’t help but reply after reading the comments.

    I helped you. The rest of your troll was deleted. -ds

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