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

From: David C Campbell <>
Date: Wed Sep 21 2005 - 18:06:55 EDT

>A. The evidence should not include problems for the theory (obviously).<

All data measurements are subject to various sources of error. Most
theories are limited in their ability to precisely predict detailed
results of something that is sufficiently complex. Thus, an
expectation of absolutely no problems whatsoever is probably
unrealistic. Perhaps it would be better to hope that the evidence
should be in general agreement with the theory.

>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.<

It may be compelling if either the focus of the theory is sufficently
broad as to make narrow predictions inappropriate or if many broad
predictions are fulfilled. Not as compelling as a more precise
prediction, but providing some degree of compulsion. Also, how
compelling something seems is a subjective judgement.

>C. The evidence severely damages all alternative theories (need to be
careful not to misrepresent or ignore the alternative theories, of

Probably any seriously promoted theory has some compatibility with the
evidence. Selection of a particular theory will reflect the perception
that it is the best explanation for all the available evidence.
However, the criteria for "best" can be somewhat problematic to pin
down, even if it is agreed that "best match for the scientific data" is
the best in question (rather than, e.g., best match for my
interpretation of Genesis; best match for my preconceived notions;
easiest to apply to a particular situation...). Thus, relativity is
generally accepted as better than Newtonian models because it works
better in some situations, although the two give practically identical
predictions about most everyday observations. However, relativity
could be made to produce an even better match with observations if we
introduce a small variable in each experiment, producing a precise
match. The variation between experiments is probably just due to
errors in the measurements, but it would be impossible to disprove the
claim that there are tiny fluctuations in everything. The concept of
"better" explanation includes a goal of maximum simplicity that is
still compatible with a good explanation, not just maximizing the
percent match between expectation and prediction.

>1. The designs of the species seem to be clustered, and the clusters
seem to cluster in larger groups, and so on, in what is called a nested
hierarchical pattern.
>2. There are a great many exceptions that violate the pattern, at all
levels, such that, for example, a paper out of Doolittle's lab has
called for a "relaxation of tree thinking."

The exceptions cited in that paper are characteristic of certain genes
in prokaryotes and are not characteristic of eukaryotes. Hybridization
can also produce networks rather than trees. There are also some
confounding factors that can make gene trees and species trees not
match (multiple ancestral alleles, etc.) Nevertheless, the broad
nested hierarchical pattern is quite consistent.

>3. There is massive convergence, meaning similar designs show up in
distant clusters.

Not sure what qualifies a convergence as massive. Convergence happens
all over the place, but there are relatively few examples that have
significantly misled people with regard to classification after
detailed study. E.g., no biological classification has put whales with

>It seems obvious that 3 fails on A, but I realize you may disagree.
Setting that aside then, obviously 2 fails on A and 1-3 all fail on B.
Also, none succeed on C. So as with the fossil evidence, I don't see
how this can be compelling evidence for evolution.<

What is evolution?

I presume we are including the premise of common descent of all
organisms on earth from one or a few ancestral forms (possibly the
abiotic origin of these forms is included) and the premise that new
forms arise from the ancestors by differential survival of offspring
that differ in some inheritable way among themselves. Perhaps
particular mechanisms, especially but not only natural selection, are
also part of the definition. The need for a clear definition of
evolution is needed to address the concern that the theory be properly

1, 2, and 3 are all fully compatible with this definition of evolution
and so do not challenge A.
1 is a direct expectation of common descent and 3 is an expectation of
natural selection, so these fall somewhat under B as supporting
evolution (don't know if they are narrow enough).
2 is mainly a function of the inheritance/transfer patterns of DNA and
does not directly address evolution.

C depends on the competing theories under consideration. Separate
creation of organisms could produce any pattern, and so there are no
narrow predictions. The fact that the patterns match the evolutionary
expectations, whereas separate creation could produce anything, makes
evolution a better scientific match. Most separate creation models
include some specific assumptions about the creator (in the advocate if
not in the model), and sometimes the observed pattern may contradict
those. Specific separate creation models often also make specific
predictions about the timing and means that do not match observations
very well.

>>If we "assume" that evolution is true, it's because there is
significant warrant for doing so.<<

A caveat to the claim that evolution is assumed to be true in most
studies: It is not actually necessary to assume that evolution is true,
but merely that it is sufficiently plausible to be worth trying an
evolutionary model. If you refuse to consider the possibility that
evolution is a valid explanation, you won't bother trying evolutionary
models. In fact, when you try an evolutionary model in analyzing
biological data, it generally works quite well.

> Yes, evolution is supposed to be a fact. What we need are
compelling evidences though. How about this: start by supplying *one*
compelling evidence.<

Facts: We observe a series of organisms in the fossil record, from more
to less primitive, and many transitions between major types. We see
patterns of molecular and morphological similarities. We can observe
new species forming in the wild and in the lab. We can see changes
occuring in populations of organisms. Thus, it is clearly a fact that
organisms change over time and that there are largely congruent
patterns that they fit into.

Theory to account for the facts: Natural selection and other selective
forces (including genetic drift, catastrophes, etc.) produces
differential survival of individuals that in some way reflects
inheritable but changeable information (now known to be DNA in almost
all cases).

It is confusing to refer to evolution as a fact and a theory, but it's
just the same with other things (observed tendency of masses to attract
each other and the mathematical model both called gravity)

>My main point is that we need to be far more circumspect about
evolution, both pre and post Darwin. Historically, the development and
subsequent justification of evolution incorporated theological
assumptions. For me, those assumptions are unorthodox. <

However, as in the example of Warfield that you note later, not all of
those involved were theologically unorthodox. More importantly,
heterodoxy is not necessary to evolution, even though it is true that
evolution has been a favorite topic to misuse in support of unorthodox
theology since Huxley. The exact means and timing of creation is
theologically largely irrelevant. However, the strict limits on
Biblical miracles as signs, pointing distinctly to God, suggests that
the creation science or ID-type miracles which could equally be
attributed to any intelligent agent are theologically unlikely (though
not outside God's power.) Biblical miracles are concentrated around
specific theological issues (YHWH versus gods of Egypt and Canaan
around the Exodus; YHWH versus Baal or syncretistic versions for Elijah
and Elisha; Jesus and the church versus paganism or legalistic versions
of Judaism) and minimize the violation of natural law (the axe head
floats, but has to be picked up and the axe repaired; water turns to
wine but has to be served in the ordinary manner; loaves and fish
multiply but the leftovers are carefully saved; Moses has advance
notice but a wind parts the sea...).

>It also seems abundantly clear that the scientific claims of
evolutionists are exagerrated and problematic. I am unaware of a single
type or category of evidence for evolution that is
compelling, yet we are told it is a fact. Something is wrong with this

Compelling is a subjective assessment; I find the evidence for
evolution quite compelling. On the other hand, scientific claims
against evolution are routinely extremely problematic if not simply

>This would be kind of a BB Warfield brand of evolution, which is
unacceptable to evolutionists because it entails detectable and
efficacious divine action.<

Not sure how the divine action is necessarily detectable. There's no
need for physical detectability of the sort wanted by ID advocates.
Rather, divine action in nature is detected primarily based on the
theological premise that God is involved in everything. Thus,
Ecclesiastes finds that examining the physical world from an "under the
sun" perspective leads to meaninglessness, and Job 28 asserts that true
wisdom is not found in the physical world but rather through the fear
of the Lord. Divine action in nature is shown better by the wonder and
beauty than by purported irreducible complexity.

>Let me give you a textbook example, pun intended. A well known
prediction of evolution that has been falsified is that homologous
structures should derive from homologous genes and embryonic
development pathways. Similar designs, in cousin species, come from
*different* genes and development pathways. Sadly, a very popular,
current high school biology text cites homologous development pathways
as *an evidence* for evolution. It could hardly be more misleading. The
fact of the matter is that this is yet another prediction that has been
falsified. Of course, the text is also writing from an
evolution-is-true perspective, so there is a circularity to their
discussion of evidences. The theory is true, so all observations
must support the theory, one way or another.<

Homologous structures routinely derive from homologous genes and
embryonic developmental pathways. The high school biology text is
correct. There are a few exceptions known. Claims written from the
evolution-is-false perspective are not remarkably trustworthy.

>Even then it was well understood (though routinely ignored) that
evolution had no explanation for how the Mendelian machine could have

Only within the past few decades have we gotten enough knowledge about
how it works at the molecular level to be able to start developing
predictions. Various explanations exist for the origin of replicated
information, though the full details are certainly not developed. Once
information is being replicated and transmittted, the
near-impossibility of entirely exact data replication will
automatically result in inheritance of variation.

>Small-scale changes for adaptation are not the result of a unguided,
random machine.<

With the caveat that unguided and random describe the physical
condition, not ultimate reality (i.e., God is sovereign over all that
happens, but many things do not require intelligent intervention, and
are thus unguided at a physical level, and are probabilistic or humanly
unpredictable, and thus describable as random-cf. the random shot that
killed Ahab), random mutations do produce small-scale changes for
adaptation. The applicability of "unguided" is debatable-although
natural laws provide an adequate physical description, natural
selection produces a strong directionality.


Evolution pedicts that there will be similarities between organisms.
UCEs do not challenge evolution as such; rather, they challenge our
understanding of patterns of molecular evolution.

>Can we imagine this sort of leniency being granted to, for instance,
special creation?<

Sure, but evolution has consistently provided a better (more precise
match; criterion B far above) explanation for things for over 150 years.

>trilobite eye, an all-time feat of optimization is "hardly surprising."<

A single distinctive feature (in the trilobites that have eyes)
constitutes an all-time feat of optimization? The unique feature of
trilobite eyes is that the calcite layer over them is aligned along the
right crystal axis so as to not distort the trilobite's vision. Apart
from that, they are not particularly different from other arthropod
compound eyes, which are not particularly different from lots of little
eyes packed together. A rudimentary ability to tell light from dark
has evident advantages and developing this further has its advantages.
The eye is one of the worst popular examples of irreducible complexity.
 Each step has evident evolutionary advantages, so it is easily
reducible, even though Darwin did not realize it.

>The DNA code, hemoglobin, echolocation, the brain, and a thousand other
wonders are now "hardly surprising."<

Given the evidence relating to their evolution, no they aren't that
surprising, at least not in the way that Johnson or Wells want.

E.g., the duplications that underlie the present set of tRNAs suggest
evolution of the present DNA translation code form a simpler pattern;
the duplications underlying the family of globins making up hemoglobin
at different stages in mammal development point to ancestry in a
simpler oxygen-carrying molecule; rudimentary echolocation (something
really big is up ahead) is useful and can then be refined; concentrated
nerves forming a central command center is obviously useful and is
increadingly developed as one looks across the animal kingdom.

Dr. David Campbell
425 Scientific Collections
University of Alabama, Box 870345
Tuscaloosa AL 35487
"James gave the huffle of a snail in
danger But no one heard him at all" A.
A. Milne
Received on Wed Sep 21 18:07:35 2005

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