Re: Miroslav Hill responds

From: Dace (
Date: Mon 05 Dec 2005 - 20:40:20 GMT

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    > From: Derek Gatherer <>
    > Exactly, the selection medium simply gets living cells dumped in on
    > top of the dead ones. The same flask is used, not a clean one. In
    > the unselected medium there is passage (which means spinning down
    > cells, taking an aliquot and seeding it into a clean flask with fresh
    > medium). So tell me then, where's the control? What is being
    > compared with what?

    Here's the relevant passage, from the bottom of page 213:

    "The serial assay was redesigned as follows. A cell line was grown from small inocula in a culture medium containing no selection agent. At each passage, one or more cell samples were withdrawn and seeded into separate flasks (instead of a depleted monolayer) containing the selection medium. In these flasks, because of selection pressure, the wt cells died while drug-resistant cells gave rise to visible colonies. Mutation frequency at each passage level of the cell line was then calculated from the total number of colonies divided by the number of cells assayed for resistance and corrected for cloning efficiency."

    What Hill has demonstrated is that when a colony of cells is subjected to a toxin and develops resistance to this toxin (over the course of generations), the same mutation enabling this resistance will also begin appearing in a closely related but physically separated culture. This indicates a nonrandom pattern of mutations in direct contradiction to neo-Darwinian orthodoxy.

    Incidentally, Hill has responded to your initial complaint, namely that if his results were true, researchers would already have spotted this phenomenon:

    Dear Ted Dace,

    Researchers don't see nonrandom mutations in unexposed cultures because they don't look for them in a good way. To my best knowledge, no one ever tried a serial assay though such assays are known from 1986 (see below). Unlike a standard procedure the serial assay "extends across several passages". This may last for several months, showing that during this time period the cell population contains no resistant mutants.Then at further passages these mutants are found at small but increasing numbers. The absence of such mutants at low passages and their occurrence at high passage levels, taken together, provide evidence of nonrandomness.

    See also Hill M and Hillova J., Non-random acquisition of ethionine resistance by Chinese hamster fibroblasts. Appendix: acquisition of thermoresistance. Biomedicine & Pharmacotherapy 40, 11-19, 1986.

    Yours sincerely, Miroslav Hill

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