Re: Is evolution really the central theory for all of biology?

From: Pim van Meurs <pimvanmeurs@yahoo.com>
Date: Tue Sep 20 2005 - 19:04:01 EDT

Cornelius Hunter wrote:

> Terry:
>
> It seems to me that to be compelling, an evidence should fulfill
> some these criteria to some reasonable degree, and not fail on them:
>
> A. The evidence should not include problems for the theory (obviously).
>
> B. The evidence should be the fulfillment of a somewhat narrow
> prediction of the theory. That is, if the evidence as well as several
> other outcomes are all accommodated by the theory, then the evidence
> is not compelling.
>
> C. The evidence severely damages all alternative theories (need to be
> careful not to misrepresent or ignore the alternative theories, of
> course).
>
> Make sense?
>
> The fossil record suggests or reveals:
>
> 1. Dramatically increasing complexity of life forms over time
> 2. Many extinctions
> 3. Rapid appearance of new species
> 4. Stasis of species once they appear
> 5. Rapid increase in biosphere diversity followed by winnowing of
> diversity (reverse of the traditional evolutionary tree, if you will)
> due to extinction. This occurs repeatedly.
> 6. Lineages (ie, there is rapid appearance, but usually the design is
> not radically different from earlier designs).
>
> I think 1 and 3 fail on A but realize you may disagree. Setting that
> aside then, I think that clearly 1-5 fail on B. None succeed on C. The
> only positive is 6 which succeeds on B. So, with 5 evidences, of a
> total of 6, failing on B and only 1 out of 6 succeeding on B, I don't
> see how this can be compelling evidence for evolution. Can you explain?
>

There are few 'competing' theories of evolution but let's look at how
well evolutionary theory does.

Could you explain your reasoning why you believe 1 and 3 to fail on A or
that 1-5 fail on B

Extinctions are somewhat irrelevant as they are often the outcome of
external circumstances. Increase of complexity seems quite well
explainable by evolutionary theory, in fact, Gould argued that even
under a random walk, evolution would inevitably increase in complexity iirc.
Speciation, gradual and stasis are all best understood when realizing
that there is a difference between morphology and the underlying genetic
encoding. Here is where (near) neutrality comes into play. In other
words, while the morphology may remain virtually unchanged over long
periods of time, the underlying genetic sequences 'evolve' mostly along
near-neutral paths.
There is some fascinating work done in this area on RNA which shows how
evolutionary processes can recapture many of the features of the fossil
record.
I believe that even Darwin addressed the issue of extinction. Most of
your arguments appear to be somewhat overly simplistic.
Could you explain your reasonings in more details?

After all, to give a similar example from mechanics, gravity can be both
accelerating and decelerating force. It depends on the circumstances as
to how gravity plays out. One cannot portray evolutionary processes in a
simplistic manner of either/or.

What other hypotheses/theories do you propose to explain 1-6 btw?
1. Simple examples of variation and selection have shown how complexity
can increase so I doubt that darwinian theory is somehow problematic in
this area.

2. Darwinian theory is both a theory of 'origin (of species)' as well as
'extinction'. In other words, competition can be both the origin as well
as the extinction of species. But extinction as found in the fossil
records shows examples of massive extinctions, often linked to natural
disasters. See http://id-www.ucsb.edu/fscf/LIBRARY/JOHNSON/Raup.html and
http://www.bbc.co.uk/education/darwin/exfiles/index.htm

Darwin himself speaks of extinction in Chapter XI of "The origins of
species". Darwin seems to believe that extinctions can be explained by
gradual disappearances.

"It is most difficult always to remember that the increase of every
creature is constantly being checked by unperceived hostile agencies;
and that these same unperceived agencies are amply sufficient to cause
rarity, and finally extinction. So little is this subject understood,
that I have heard surprise repeatedly expressed at such great monsters
as the Mastodon and the more ancient dinosaurians having become extinct;
as if mere bodily strength gave victory in the battle of life. Mere
size, on the contrary, would in some cases determine, as has been
remarked by Owen, quicker extermination from the greater amount of
requisite food."

Darwin's main shortcoming is the unfamiliarity with the great
extinctions and their plausible causes. Massive extinctions on short
time scales are quite reasonable.

3. Rapid appearance of species. I need more detail as to what your
argument here is. Are you refering to the punkeek nature?

I have already touched on 4 and 5 seems to be duplicating the earlier ones.
Received on Tue Sep 20 19:06:37 2005

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