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Re: [creationevolutiondebate] Re: Genetic Recombination

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  • Dave Oldridge
    ... OK, but I include such new alleles under the heading of mutations. ... We re getting much faster at it actually. And it is only necessary to actually
    Message 1 of 87 , Jul 31, 2001
      On 31 Jul 2001, at 18:34, Chris Ashcraft wrote:

      > --- Dave Oldridge <doldridg@...> wrote:
      > > By starting with
      > > monoclonal breeding
      > > stock. These have been carefully bred and cloned to
      > > have only one
      > > allele at each site.
      >
      > The fact that new alleles accumulate is a given, but
      > the question remains where do they come from? We can
      > not yet determine if they have resulted from errors
      > during replication, or were created by crossing-over
      > reactions during meiosis. Although recombination is
      > specifically performed to create the variable
      > characteristics we see between siblings, it is
      > overlooked as a source of new alleles. This is an
      > assumption, and incorrect...

      OK, but I include such new alleles under the heading of mutations.

      > > You can also
      > > sequence all or part
      > > of the parent's DNA and the offlpring's.
      >
      > It takes years to sequence a single cell. No sexually

      We're getting much faster at it actually. And it is only necessary
      to actually sequence a small strand as long as identical locations
      are sequenced.

      > reproducing parent cell and its offspring before and
      > after meiosis have yet been sequenced. Until gametes
      > are sequenced before and after recombination, we will
      > remain ignorant of the reactions being performed..

      Perhaps, but that does not mean we are totally ignorant of the
      results of such reactions.

      > > Any segment that is not
      > > found in one of the parents' alleles is a mutation,
      > > regardless of what
      > > caused it..
      >
      > The accumulation of new alleles is assumed to have
      > been caused by mutations, but crossing over reactions
      > are not considered mutations unless they have resulted
      > in a truncated or elongated homologue. An individual

      You must be working from a different definition. I'll stick with the
      one I've been using. It's the only useful one when studying
      evolution.

      > which carries mutation is called a mutant. Offspring
      > varieties are termed recombinants, not mutants, and
      > yet each an every gamete have sequences which were
      > altered during meiosis.

      In diploid organisms meiosis usually results in a random
      combination of the parent's alleles, plus a small number of
      mutations (sites where the allele is not the same as any of the
      parents' alleles). In that respect, the vast majority of humans are
      "mutants" by your definition above.

      > A mutation is any change in the genomic sequence, but
      > recombination creates new haploid genotypes. Any
      > change in the genomic sequence of the offspring
      > following fertilization is termed a mutation, but
      > crossing-over reactions during meiosis are not...

      Apparently by your definition, not mine.

      > Regardless; the point at hand is whether or not new
      > alleles and therefore evolution are the result of
      > reactions performed by the cell during meiosis or
      > random copying errors. Atheistic evolution presupposes

      There is no such science as "atheistic evolution." Nor does it
      presuppose anything.

      > there is no design behind the creation of new alleles,
      > and they are therefore accumulating through
      > extracellular mechanisms. The fact is, new alleles and
      > therefore evolution are the result of cellularly
      > performed rearrangements called Crossovers...

      Actually, new alleles have been observed to arise from every known
      type of mutation.

      > > > There is no question recombination is the primary
      > > > source of offspring variability, and these
      > > reactions
      > > > are almost completely uncharacterized.
      > >
      > > No, they are actually fairly well understood.
      >
      > Then enlighten us with a list of the proteins involved
      > in meiotic recombination and the reactions they
      > catalyze. The fact is we have not yet isolated one
      > single protein involved in meiotic recombination.
      > These reactions are still completely uncharacterized.

      You're missing the point. If the copy is not the same as the
      original, it's a "random copying error" no matter WHAT the physical
      cause of it. What part of this don't you get?

      > > And with
      > > isolation, two
      > > populations will actually diverge even with no
      > > selection pressure at
      > > all. Even in identical environments.
      >
      > That's not true. Without selection favoring one
      > genotype over another there will be no genetic drift.

      This is simply wrong. So wrong, it's almost ludicrous. What is
      going to make the neutral drift in two isolated populations "track."
      Do you have a name for this mysterious force or even a shred of
      evidence for its existence?

      > Populations will only diverge if the selective
      > pressures differ.

      Wrong. Contrary even to intuition, never mind measured data. I
      challenge you to try it yourself. Take two colonies of fruit flies and
      breed them in identical conditions for a dozen years and then see
      what you have.

      > Genetic incompatibility develops if the history of
      > recombination and selection has caused enough genetic
      > deviation so that the homologues are unable to pair
      > and crossover during the first mitotic division
      > following fertilization..

      Or if the number of frame shift and duplication mutations has
      exceeded the tolerance of the system.




      Dave Oldridge
      ICQ 1800667
    • Paul Andrew King
      ... Only technically, if you include special creation events. Now the definition you;re quoting is fine in the context of evolution as an ongoing process in
      Message 87 of 87 , Aug 14, 2001
        >(MAWduke) Also, I believe Dave O. had refs to research starting
        >with identical drosophila (monoclonal?) which produce variation
        >given many generations. So org's with longer lifespans/generation
        >times will take much longer, even if mutation rates are identical, to
        >produce similar variability.
        >
        >(Bradbury) Very true. Most creationists, well accept that mutations
        >are a significant player in the real-world "shift of allele frequencies
        >within a population's gene pool over time." However, the semantic
        >inadequacy (confusion causing, unacceptable ambiguity) of this as a
        >scientific definition for 'evolution' (as championed by Susan, Shubi,
        >Flank, et al) is rather well illustrated to the extent this same
        >phrase is equally descriptive of 'evolution's' opposite, namely,
        >'creation'.

        Only technically, if you include special creation events.

        Now the definition you;re quoting is fine in the context of evolution
        as an ongoing process in the here-and-now. And given your focus on
        that sort of observation it would seem to be the appropriate one.
        >
        >Evolutionists (interpret, visualize) these "shifts" as somehow
        >producing necessary new, viability enhancing DNA code over time
        >-- insisting this admittedly rare and difficult (impossible?) to confirm
        >
        >extrapolations of available evidence is the proper, best, and only
        >interpretation to be considered.

        Because of the very strong evidence that that is what happened.

        >
        >On the other hand, creationists accept the undisputed physical
        >evidence at face value -- Namely, that the long term effect of
        >mutation and other random "shifts" in functioning gene pools, on
        >balance, produces loss, not gain, of beneficial genetic code as is
        >repeatedly and continually observed in gene pools over time.

        Dave, you;re passing off a disputed and selective interpretation of
        the evidence off as an unquestioned fact.

        >
        >As you can see the "...shifting of gene frequency..." criteria is
        >equally descriptive of both 'evolution' and 'creation' -- and as such
        >is too vague and ambiguous to be of any real value in science.

        Until you see a special creation event there is no obvserved
        *Creationist* mechanism for changing allele frequencies.

        >Additional criteria establishing the nature and extent of the observed
        >"changes" must necessarily be included before a useful, mutually
        >acceptable definition of 'evolution' can be established.
        >
        >(MAWduke) I guess you are anti-evolution?
        >
        >(Bradbury) Can't speak for Chris Ashcraft, but for myself I am
        >open-minded as to "scientific" findings concerning 'evolution' ('age of
        >the earth', 'origin of life', etc.) -- but seriously disagree with the
        >way interpretative and untested hypotheses, lacking physical and/or
        >mathematical confirmation, are presented to the public as properly
        >qualified "scientific" fact or theory.

        Then please don't do so.

        >
        >(MAWduke continues) Regardless, there are observed varieties of
        >mutations (crossover not occurring 'between genes' as normal, copies,
        >etc). There are observed differences in genomes of different species.
        >Given that the #nucleotides differing between pairs of species is
        >countable, and in many cases not too high, what is to prevent the
        >observed mutation-types from EVENTUALLY bridging the gaps?
        >(for 'close' species at least)
        >
        >(Bradbury) Yep, such changes DO occur ... and do "shift the allele
        >frequency in a population gene pool over time." The great majority
        >of such changes demonstrably resulting in degradation (decay,
        >death, extinction). Many thousands and thousands of bell jar fruit
        >fly and other carefully contrived (accelerated mutation rates, etc.)
        >experiments well confirm the loss, not gain, of beneficial genetic
        >information.

        Whaty about the observed beneficial mutations ?

        >
        >Mathematicians, information theorists, physicists, engineers, etc., all
        >working closing with and desiring to confirm biologist's evolutionary
        >conclusions have openly concluded the probability of random
        >mutation, natural selection, etc. (as quantified by recognized
        >evolutionary authorities) providing such code as so improbable as to
        >be impossible ... on either an earthly or astronomical time frame.
        >Postulating more time (millions or billions more years) is not the
        >answer either as the rate of accumulation of recessive negative
        >characteristics (to the point of lethality) relatively early on exceeds
        >even the most optimistic rates of postulated beneficial code formation.

        Interesting that you don't mention biologists. Seems to me that
        you're relying on theory.

        >
        >If you're interested, I'm sure you'd find the following paper most
        >interesting. Particularly the summary remarks by Mathematician/
        >Engineer Murray Eden, invited by Medawar and speaking before his
        >hand-picked study group (including Mayr, Waddington, Sidney Fox,
        >Eiseley, Ulam, Kettlewell, Lewontin plus 20 others) brought together
        >to formally study/analyze this "probability" problem. I obtained my
        >(years ago) via Library Interloan, but I suspect at this date it might
        >well be available (somewhere) on the net as well.
        >
        >MATHEMATICAL CHALLENGES TO THE NEO-DARWINIAN
        >INTERPRETATION OF EVOLUTION. Symposium held at
        >Wistar Institute of Anatomy and Biology, April 1966 and published
        >as Wistar Symposium Monograph Number 5 by Wistar Institute
        >Press, Philadelphia. (111 pages plus).

        That *is* thirty-five years old. Mathematical modelling is only as
        good as the models and the data used. I wouldn't rely on thirty-five
        year old models in a complex and advancing field of study. For
        instance the Neutral Theory was only *proposed* in 1968.

        >
        >They address you question as to what might prevent the
        >"EVENTUAL" accumulation as mutation to bridge the gaps as
        >asked above. On a biological level by Dr. Mayr on Pg. 50 where
        >he reminds us of the barrier to prolonged accumulation of beneficial
        >mutations posed by what they term, "maintenance evolution".
        >Describing this saying, "This is all kinds of stabilizing and
        >normalizing selection that protect a species or a gene pool from
        >genetic and evolutionary change, once that species or gene pool
        >has acquired adequate adaptation to its environment. Much, if not
        >most natural selection is concerned with this maintenance evolution."

        In fact it's questioned whether there is enough maintenance selection
        to explain the observed stasis in the fossil record. This is not an
        adequate mechanism to prevent evolution - only to slow it down (and
        the observed rate is well below the theoretical maximum - or the
        observed maximum in laboratroy experiments).

        >
        >Dr. Eden, speaking as a mathematician, concludes in his working
        >paper summary that "It is our contention that if 'random' is given a
        >serious and crucial interpretation from a probabilistic point of view,
        >the randomness postulate is highly implausible and that an adequate
        >scientific theory of evolution must await the discovery and elucidation
        >of new natural laws -- physical, physico-chemical and biological."

        It would be worth asking *which* "randomness postulate" he had in
        mind, the arguments against it and whether the assumptions behind
        those arguments are still defensible.

        >
        >If the term "scientific" can be stretched to apply to evolutionists
        >conclusions requiring some yet-to-be-scientifically-established natural
        >law

        What conclusions would those be ? I can't think of any solid
        conclusions that would require such a thing.

        >(mimicking the intelligence recognized as sufficient to accomplish
        >the changes involved -- is it any less "scientific" for
        >non-evolutionists
        >to postulate alternative conclusions base on a historically identified,
        >but yet-to-be-scientifically-established, alternative source for this
        >necessary intelligence?

        Historically identified ? I have no idea what source you could be
        talking about if you mean that it's existence has been proven to even
        the standards used by historians. And even that is a lower standard
        than applied to evolution.

        >
        >(MAWduke) Are you young Earth too? given 1,000,000 yrs a lot
        >more mutation space will be explored than in any experiments done
        >currently.
        >
        >(Bradbury) This is a historical, not a scientific question. How old do
        >
        >you WANT to be? There is a lot inconclusive, and often apparently
        >conflicting evidence from which to choose.

        There is ? There are a lot of *bad* arguments for a young Earth -
        and a lot of strong evidence that the Earth is very much older than
        the 10,000 years allowed by YECs.


        > I can live with whatever
        >may someday be determined ... but, for now, consider it possibly part
        >of a Biblical "mystery" and an open scientific question.

        It is not an open scientific question as to whether the Earth is
        older than 10,000 years.

        > Here non-
        >evolutionists (creationists) appear to have a real advantage. They are
        >free to go where-ever the evidence leads ...

        Since the only people who believe on a young Earth are those whose
        religious beliefs commit them to that view it would seem that there
        is no advantage at all.

        > while pro-evolutionists
        >are compelled to seek out and embrace only that selective evidence
        >which can be interpreted to give them the ancient ages their
        >philosophical concept requires.

        This is just mud-slinging without foundation. If YEC's aren't biased
        in EXACTLY the way you suggest. then why do they come up with such
        obviously silly arguments as the ones based on human population or
        the salt content of the oceans ?
        --
        --
        "The T'ang emperors were strong believers in the pills of
        immortality. More emperors died of poisoning from ingesting minerals
        in the T'ang than in any other dynasty" - Eva Wong _The Shambhala
        Guide to Taoism_

        Paul K.
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