Re: Letter to the Editor: Proponents of creationism don't have a hidden agenda

On Nov 7, 5:25 pm, "Pip R. Lagenta" <morbiusatw...@xxxxxxxxxxx> wrote:
On Wed, 07 Nov 2007 07:27:03 -0800, chris thompson



<chris.linthomp...@xxxxxxxxx> wrote:
On Nov 6, 9:35 pm, Shane <remarcsdNOS...@xxxxxxxxxxxxxx> wrote:
On Tue, 06 Nov 2007 17:39:38 -0800, Ray Martinez wrote:
On Nov 6, 4:55 pm, "Alpha Male" <BOPE.Elite.Sq...@xxxxxxxxx> wrote:
On Tue, 06 Nov 2007 22:38:50 -0200, Jason Spaceman
[snip]
Shay Talley

Daily Lobo reader
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Read it at
http://media.www.dailylobo.com/media/storage/paper344/news/2007/11/05...
orhttp://tinyurl.com/2guoa7

J. Spaceman

Evolution is NOT a random process!- Hide quoted text -

- Show quoted text -

Then why is the word 'random' used to describe mutation events and the
evolutionary process?

Mutation events of, and by, themselves are not evolution. If they
confer a reproductive/survival advantage that is actually realised,
then they are naturally selected and evolution can then be said to
have occurred. Therefore it is quite logical--and objective people see
this easily--for mutation to be random, but evolution to be
non-random.

This is incorrect. Mutation, by itself, is evolution.

Really? A mutation would change the genetic makeup of a *single*
member of a population. I don't think it is evolution until after the
mutation has occurred. Then, it is a trait subject to Natural
Selection (i.e. evolution).

Do not equate evolution with natural selection. NS is only one
possible mechanism by which evolution occurs. Mutation is certainly
another.

Consider an asexually reproducing individual. That individual
experiences a replication error while copying its DNA prior to
reproduction. That's a mutation. Let's assume it isn't lethal. The new
individual has a genetic makeup different from its parent. The
individual did not evolve, but the population did.

Let's say the population consisted of 99 individuals in the instant
before that one reproduced, and the gene in question had no variation-
it was fixed. All 99 individuals had a genotype of AA at that locus.
The new, 100th individual is Aa. Our population has gone from an
allele frequency for A=1.0 (fixation) to an allele frequency for
A=0.995 and f(a)=0.005. Note that in a population of 100 diploid
individuals, there are 200 alleles.

Do you see that no individual has evolved, but the population has? On
top of that, the mutation could be completely neutral, not subject to
natural selection at all, and it is _still_ evolution.

Mutation has _always_ been considered both a cause of evolution and
the source of genetic variation. Any General Biology text will list 5
causes of evolution: mutation, natural selection, drift, nonrandom
mating, and gene flow.

If you define
evolution as a change in the genetic makeup of a population, mutation
certainly falls into that category.

Really? A population's genetic makeup can mutate?

No, of course not. But that's not what I said. I said that a mutation
in an individual causes a change in the genetic makeup of the
population. Think in terms of allele frequencies as I described above
and it should make more sense.

All at once?

Yes, in the case of mutation, evolution is instantaneous. And it
doesn't take *every* individual changing for evolution to occur. If
they all changed at once in the same way, natural selection couldn't
happen, could it? Or at least any differences in reproductive success
would not have a genetic basis.

Or
would the same genetic mutation happen repeatedly over time to the
various members of the population? How would that work?

All loci have mutation rates. Some are more highly conserved than
others. John Harshman or Howard Hershey would be better at describing
this, but that's the way it is. In addition, all mutations have a
"back-mutation" rate which negates the initial mutation. So the same
mutation can happen to multiple individuals- jeez, look at single-gene
enzyme deficiencies in humans. There's a rate at which they occur. I
know this isn't the question you were asking, but it's the right
answer.

Mutation is the source of genetic vatiation for the other causes of
evolution, to be sure.

That, I understand.

However, that doesn't mean it isn't evolution
in and of itself.

If mutation occurs in an individual, and evolution happens to a
population, how can mutation be evolution?

Where do you think evolution at the population level comes from? It
has to be different individuals that make up the population, no?

Chris


That being said, Ray is of course still lying about "random" and such.
Mutation events are random with regard to utility, but selection is
not. That Ray is still prattling on about this is simply evidence of
his dishonesty.

Chris
[snip]

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President for Life
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