<< Subj: Re: evolution archive list
CC: Huxter4441@aol.com
Hi Huxter,
<< I asked Susan::
>> In his latest book, At Home in the Universe or Nature's Destiny, (I can't
>> remember which is his and which is Kauffman's book) Denton says he is not
>>a creationst. Do you not take his word for it?
You replied:
>***** Why should anyone take his word? In EATIC, he used 14 year-old
>cytochrome-c data to prop up his 'typology' approach, despite the fact that
>as recently as 4-5 years before it EATIC was published, there was a major
>re-evaluation of that data with additional data using more stringent
methods
>of analysis that demonstrated that the 'evolutionist view' of phylogeny was
>correct. I consider that a major error of omission, one that should not be
>taken lightly, especially when he was attempting to bolster his
anti-evolutionary claims 'scientifically..
I am not qualified to judge whether Denton used out-of-date data in
Evolution
a Theory in Crises. If he did, it would hardly invalidate everything he said
thereafter. Few people are as infallible as I. (I never makes an error
:-))
We each have our prejudices. You might distrust anyone who criticizes
Darwinism; I tend to be skeptical of anyone who too passionately defends it.
But I try to listen anyway. Nevertheless, the question was whether Susan
believed Denton when he said in his latest book that he is not a
creationist.
I can't imagine not believing anyone on such a question. I'll take
anyone's
word that they sincerely believe what they say they believe.
##### Sincerity or none, Denton used out of date data for his claims, and as
one familiar with the literature and how to search it, he MUST have known
about the more recent papers. Then it becomes a question of motive. WHile
it is not uncommon for researchers to use 'old' data to support a claim, it
is uncommon for them to use 'old' data that has been supplanted by newer,
more complete data. He can 'believe' whatever he wants to, but if he is
going to use scientific evidence to prop up his beliefs, he'd be well advised
to use data that actually supports him.
I asked:
>Question no 3:
>I've heard "common ancestor" written in the plural, conceding the
>>possibility of more than one. If there could be 2, or 5, or 10 common
>>ancestors, why not 100--or 1000? Where would biology set the limit?
Does
>>one common ancestor insist that life arose only once--and everything
>>descended from that one unique event? What if life is discovered to be
>>common in the universe? Similar DNA apparently results in similar
>>morphology, but is that necessarily proof of common descent?
>
>***** I'll give it a brief shot. (Question on common ancestry) Despite the
>creationist propaganda available on the web (e.g., David Plaisted's
treatment >of it, and innumerable 'private' antievolution home pages - a
simple Yahoo >search on evolution will demonstrate this) it is not merely
genetic 'similarity' >that is the issue - though of course that too can be
informative. It is the >pattern of synapomorphic (shared derived) mutations
that is indicative of >descent. These patterns are statistically
significant
indicators of a hierarchical
>structure in any given dataset (of homologous DNA sequences) - for
>numerous
treatments of the statistical analyses/methodologies see just about
>anything
by Huelsenbeck, Hillis, Felsenstein, or Swofford. Creationists often >trot
out those 'improbability statistics' claiming that such-and-such an equation
>PROVES evolution couldn't have happened (of course, these equations are
>almost always based on improbable assumptions and deal with abiogenesis,
>not evolution, but the two are forever joined in anti-evolution orthodoxy).
I
>have asked this question on numerous discussion boards - what are the
>chances that any 2 species with genomes in the 6 billion base range could
>share - by chance - a mutation at a specific locus? 3? 4? How about 10?
My
>admittedly crude analysis of the chances that only 2 would share such a
>mutation - modelled on statistical equations used by creationists, btw -
>produced something in the range of 1 in 10^67. Now take into account that
>there are hundreds - thousands - of instances of shared mutation in related
>species. Even if my orginal estimate is off by several orders of
magnitude,
>it is clear that as more species are taken into consideration, and more and
>more loci are brought into play, that it is statistically 'impossible' for
>the observed structure of shared mutations could arise by chance. And
before
>the 'Oh, well, if they look alike you would expect similarities' argument
is
>trotted out, the bulk of the information I am referring to is in non-coding
>DNA regions, which would not have no bearing on morphology or >physiology.
The answers I typically get are: 1) no answer 2) with design, all >things
are
possible 3) God put them there for some reason. None of which >actually
address the point.
>So, to sum up, it is hardly just 'similarity' in the genomes of organisms
>that indicate descent.
Bertvan:
Your information is interesting and seems compelling evidence for common
descent. Thanks. You say the bulk of the mutations are in non-coding DNA
regions. (Am I right?) Therefore they couldn't have evolved. (Not by
Natural Selection, anyway.)
##### They most certainly could (can) - it is called drift. Since the DNA in
these non-coding regions is neither detrimental nor beneficial, mutations
therein can become fixed in a population, and 'spred' via descent. This is
'covered' by the neutral theory, which has a great deal of observational
support in its support.
Do you believe they are random nonsense, or do
you believe they contain information? Do you regard non coding DNA as
"junk", or do you believe it plays a role in the evolutionary process?
#### I would not say non-coding regions are 'random nonsense' - at least not
all such regions. Some areas of non-coding (i.e., those that do not specify
a protein product) DNA are involved in the regulation of gene expression by
providing binding sites for proteins involved in such activity. Most,
however, are not, as can be seen in experiments in which large amounts of
these regions are removed with no detrimental effects, or even in observed
instances of large-scale natural deletions. My own hunch (for which I have
no evidence, just an observation) is that the bulk of what is now 'junk' DNA
may at one time have been functional genes, or duplicates of functional
genes, that were mutated out of service, and which are now free from the
contstraints of selection. Pseudogenes - genes that have had their promoter
regions 'turned off' via mutation, accumulate mutations at 4 times the rate
of functional genes. What do you mean by 'information?'
Bertvan >>