Re: [creationevolutiondebate] Re: Genetic Recombination
- On 31 Jul 2001, at 18:34, Chris Ashcraft wrote:
> --- Dave Oldridge <doldridg@...> wrote:OK, but I include such new alleles under the heading of mutations.
> > 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...
> > You can alsoWe're getting much faster at it actually. And it is only necessary
> > sequence all or part
> > of the parent's DNA and the offlpring's.
> It takes years to sequence a single cell. No sexually
to actually sequence a small strand as long as identical locations
> reproducing parent cell and its offspring before andPerhaps, but that does not mean we are totally ignorant of the
> after meiosis have yet been sequenced. Until gametes
> are sequenced before and after recombination, we will
> remain ignorant of the reactions being performed..
results of such reactions.
> > Any segment that is notYou must be working from a different definition. I'll stick with the
> > 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
one I've been using. It's the only useful one when studying
> which carries mutation is called a mutant. OffspringIn diploid organisms meiosis usually results in a random
> varieties are termed recombinants, not mutants, and
> yet each an every gamete have sequences which were
> altered during meiosis.
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, butApparently by your definition, not mine.
> 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...
> Regardless; the point at hand is whether or not newThere is no such science as "atheistic evolution." Nor does it
> 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 design behind the creation of new alleles,Actually, new alleles have been observed to arise from every known
> 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...
type of mutation.
> > > There is no question recombination is the primaryYou're missing the point. If the copy is not the same as the
> > > 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.
original, it's a "random copying error" no matter WHAT the physical
cause of it. What part of this don't you get?
> > And withThis is simply wrong. So wrong, it's almost ludicrous. What is
> > 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.
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 selectiveWrong. Contrary even to intuition, never mind measured data. I
> pressures differ.
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 ofOr if the number of frame shift and duplication mutations has
> 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..
exceeded the tolerance of the system.
>(MAWduke) Also, I believe Dave O. had refs to research startingOnly technically, if you include special creation events.
>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,
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.
>Because of the very strong evidence that that is what happened.
>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.
>Dave, you;re passing off a disputed and selective interpretation of
>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.
the evidence off as an unquestioned fact.
>Until you see a special creation event there is no obvserved
>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.
*Creationist* mechanism for changing allele frequencies.
>Additional criteria establishing the nature and extent of the observedThen please don't do so.
>"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.
>Whaty about the observed beneficial mutations ?
>(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
>Interesting that you don't mention biologists. Seems to me that
>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.
you're relying on theory.
>That *is* thirty-five years old. Mathematical modelling is only as
>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).
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.
>In fact it's questioned whether there is enough maintenance selection
>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."
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).
>It would be worth asking *which* "randomness postulate" he had in
>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."
mind, the arguments against it and whether the assumptions behind
those arguments are still defensible.
>What conclusions would those be ? I can't think of any solid
>If the term "scientific" can be stretched to apply to evolutionists
>conclusions requiring some yet-to-be-scientifically-established natural
conclusions that would require such a thing.
>(mimicking the intelligence recognized as sufficient to accomplishHistorically identified ? I have no idea what source you could be
>the changes involved -- is it any less "scientific" for
>to postulate alternative conclusions base on a historically identified,
>but yet-to-be-scientifically-established, alternative source for this
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.
>There is ? There are a lot of *bad* arguments for a young Earth -
>(MAWduke) Are you young Earth too? given 1,000,000 yrs a lot
>more mutation space will be explored than in any experiments done
>(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.
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 whateverIt is not an open scientific question as to whether the Earth is
>may someday be determined ... but, for now, consider it possibly part
>of a Biblical "mystery" and an open scientific question.
older than 10,000 years.
> Here non-Since the only people who believe on a young Earth are those whose
>evolutionists (creationists) appear to have a real advantage. They are
>free to go where-ever the evidence leads ...
religious beliefs commit them to that view it would seem that there
is no advantage at all.
> while pro-evolutionistsThis is just mud-slinging without foundation. If YEC's aren't biased
>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.
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_