Re: Acceptance of macroevolution

Stephen Jones (sejones@ibm.net)
Fri, 19 Dec 97 20:33:04 +0800

Loren

On Sun, 14 Dec 1997 19:40:37 -0500 (EST), Loren Haarsma wrote:

>Ron Chitwood asked:

RC>>I begin my sojourn with this question. Why is macro-evolution
>>almost universally accepted by our learning institutions?

LH>I would summarize the answer in two words: Nested Homologies.

Disagree. IMHO the *real* reason that macro-evolution is almost
universally accepted by our learning institutions is because only
materialist-naturalist theories are permitted in science, as your
National Academy of Sciences affirmed in 1984:

"Creation-science is not science, said the Academy in its argument
to the Supreme Court, because `it fails to display the most basic
characteristic of science: reliance upon naturalistic explanations.
Instead, proponents of "creation-science" hold that the creation of
the universe, the earth, living things, and man was accomplished
through supernatural means inaccessible to human understanding.'"
(National Academy of Sciences, "Science and Creationism: A View from
the National Academy of Sciences", 1984, in Johnson P.E., "Darwin on
Trial", 1993, pp7-8).

While the Academy was referring to YEC, progressive-creation would be
ruled out by the same criteria.

In any event, nested homologies support some form of comon descent -
which is a *relationship*. It does not establish macro-evolution,
which is a *mechanism*. Also, common descent does not even uniquely
support Darwinism. In fact the idea of homology as evidence for
common descent goes back at least as far as St. Hilaire who predated
Darwin by 40 years:

"Long before Darwin, naturalists were divided into evolutionists
(Buffon, Lamarck, St. Hilaire, etc.), and anti-evolutionists...But
both pro-and anti-evolutionists were equally struck by the similarity
of organs and designs in otherwise widely different species. The
term 'homologue organ' was actually coined by Geoffroy St. Hilaire.
His Philosophie Anatomique published in 1818, starts with the
question: '...Is it not generally acknowledged that vertebrates are
built up on one uniform plan e.g., the forelimb may be modified for
running, climbing, swimming or flying, yet the arrangement of bones
remains the same....? (St. Hilaire G., quoted by Hardy A.C., "The
Living Stream", 1965, p50, in Koestler A., "The Ghost in the
Machine", 1967, pp137-1387)

Indeed, as Denton points out, common descent is "compatible with
almost any philosophy of nature", including "creationist":

"It is true that both genuine homologous resemblance, that is, here
the phenomenon has a clear genetic and embryological basis (which as
we have seen above is far less common than is often presumed), and
the hierarchic patterns of class relationships are suggestive of some
kind of theory of descent. But neither tell us anything about how
the descent or evolution might have occurred, as to whether the
process was gradual or sudden, or as to whether the causal mechanism
was Darwinian, Lamarckian, vitalistic or even creationist. Such a
theory of descent is therefore devoid of any significant meaning and
equally compatible with almost any philosophy of nature." (Denton
M., "Evolution: A Theory in Crisis", 1985, pp154-155)

LH>When we compare the amino acid sequences across difference
>species, we find that species which are "closer" to each other (as
>established by body type and by the fossil record) have more
>homologous genes. Species farther apart have less homologous
>genes....Moreover, the pattern of homologies is "nested"...So there
>is a pattern of nested homologies in the sequences of genes. There
>is also a pattern of nested homologies in genome organization...And
>there is a corresponding pattern of nested homologies in the
>anatomies and the developmental programs across the species. And,
>as a general rule, these nested homologies match the fossil
>record...But despite the incompleteness, wherever we look at genes
>or anatomies or fossils, the pattern of nested homologies keeps
>popping up. And when a pattern is that persistent, it just begs for
>a comprehensive theory to tie it all together --- in this case:
>common ancestry and descent by modification.

Agreed, but there is nothing really new in this. It is an extension
the old argument from homology set out by Darwin in Chapter XIV of
the Origin of Species. It is good evidence for common descent but
not necessarily for *Darwinian* macroevolution.

But there is one problem for *Darwinian* evolution. Darwin expressly
defined body-part homology as corresponding to embryonic-part
homology:

"HOMOLOGY.-That relation between parts which results from their
development from corresponding embryonic parts, either in different
animals, as in the case of the arm of man, the fore-leg of a
quadruped, and the wing of a bird; or in the same individual, as in
the case of the fore and hind legs in quadrupeds, and the segments or
rings and their appendages of which the body of a worm, a centipede,
etc., is composed. The latter is called serial homology. The parts
which stand in such a relation to each other are said to be
homologous, and one such part or organ is called the homologue of the
other. In different plants the parts of the flower are homologous,
and in general these parts are regarded as homologous with leaves."
(Darwin C., "The Origin of Species", 6th Edition, Everyman's Library,
1967 reprint, p469).

But the problem for Darwinism is that homologous body parts in
different animals are not necessarily produced by the same parts of
the embryos:

"The validity of the evolutionary interpretation of homology would
have been greatly strengthened if embryological and genetic research
could have shown that homologous structures were specified by
homologous genes and followed homologous patterns of embryological
development. Such homology would indeed be strongly suggestive of
"true relationship; of inheritance from a common ancestor" . But it
has become clear that the principle cannot be extended in this way.
Homologous structures are often specified by non-homologous genetic
systems and the concept of homology can seldom be extended back into
embryology. The failure to find a genetic and embryological basis
for homology was discussed by Sir Gavin de Beer, British embryologist
and past Director of the British Museum of Natural History, in a
succinct monograph Homology, an Unresolved Problem.... In De
Beer's words:

`It does not seem to matter where in the egg or the embryo the living
substance out of which homologous organs are formed comes from.
Therefore, correspondence between homologous structures cannot be
pressed back to similarity of position of the cells of the embryo or
the parts of the egg out of which these structures are ultimately
differentiated.'

(Denton M., "Evolution: A Theory in Crisis", 1985, pp145-147)

Moreover, homologous structures are not always specified by
homologous genes:

"The evolutionary basis of homology is perhaps even more severely
damaged by the discovery that apparently homologous structures are
specified by quite different genes in different species...As De Beer
says, `Homologous structures need not be controlled by identical
genes and homology of phenotypes does not imply similarity of
genotype.' (Denton, p151)

LH>Now there are (at least) two versions of "common ancestry and
>descent by modification" which fit the patterns of nested
>homologies: (1) macroevolution, and (2) a progressive creation in
>which God intervenes, at various times during the billions-years
>history, by modifying pre-existing forms in steps to make new
>lifeforms. We cannot yet empirically distinguish between these two
>theories.

Agreed. Dennett admits that "...there are no sure marks of natural,
as opposed to artificial, selection....It would be foolhardy,
however, for any defender of neo-Darwinism to claim that contemporary
evolution theory gives one the power to read history so finely from
present data as to rule out the earlier historical presence of
rational designers..." (Dennett D.C., "Darwin 's Dangerous Idea,
1995, pp317-318).

In fact no one can come up with a plausible, near-puniversally
accepted naturalistic mechanism of *Darwinian* macroevolution that
can accomplish the really major changes in the history of life. Some
major steps (eg. reptile-mammal, dinosaur-bird, ape-man) seem to
me to be more consistent with progressive creation than with
naturalistic evolution. For example:

"...there are voices among contemporary biologists - I mean voices
other than mine - who might cast doubt on the Darwinian paradigm
that has dominated discussion for the past twenty years. Gradualists
and saltationists alike are completely incapable of giving a convincing
explanation of the quasi-simultaneous emergence of a number of
biological systems that distinguish human beings from the higher
primates: bipedalism, with the concomitant modification of the pelvis,
and, without a doubt, the cerebellum, a much more dexterous hand,
with fingerprints conferring an especially fine tactile sense; the
modifications of the pharynx which permits phonation; the
modification of the central nervous system, notably at the level of the
temporal lobes, permitting the specific recognition of speech. From
the point of view of embryogenesis, these anatomical systems are
completely different from one another. Each modification constitutes
a gift, a bequest from a primate family to its descendants. It is
astonishing that these gifts should have developed simultaneously.
Some biologists speak of a predisposition of the genome. Can anyone
actually recover the predisposition, supposing that it actually existed?
Was it present in the first of the fish? The reality is that we are
confronted with total conceptual bankruptcy." (Schutzenberger M-P,
"The Miracles of Darwinism: Interview with Marcel-Paul
Schutzenberger", Origins & Design, Vol. 17, No. 2, Spring 1996,
pp10-15)

LH>In stellar evolutionary theory, we *can* empirically distinguish
>between interventionist and non-interventionist models. We have
>enough knowledge about gravity, electromagnetism, and nuclear forces
>that we can construct detailed, empirical models about how stars
>should form and develop. We can calculate rates, sizes, lifetimes,
>and ratios, and compare those predictions to astrophysical
>observations. We see that a non-interventionist model fits the
>data, so we feel safe in concluding that it is probably true.

As a Christian, I presume you concede that God must have intervened
in some sense in originally creating the cosmos? That God may not
have intervened supernaturally thereafter in stellar history, does
not mean He didn't intervene supernaturally in biological history.
After all, as a Christian, you do concede He has intervened in the
human history?

While we may know a lot about the formation of stars, we presumably
do not know much empirically about solar systems, since we can only
really observe our own. Our solar system has just the right features
for life as we know it - a sun the right size, planets spaced the
right distance apart, an Earth with just the right balance of
life-permitting properties, and giant planets which "vacuum clean"
asteroids, etc. We cannot know if our solar system is typical or
if it is unique in the whole universe. The argument from SETI silence
is more consistent with the latter. If our solar system is unique,
it would be evidence that an Intelligent Designer may have intervened
supernaturally in assembing its unique features to permit life.

Mowever, there is one item where God may have intervened
supernaturally and that is in the setting up the Earth-moon system.
Hugh Ross points out that the moon was probably formed from an
asteroid impact on the Earth:

"A fourth hypothesis was shrugged off for decades because it seemed
too unlikely. But today it is favored, for it matches much of the
observational data. I'll call it the Collision Hypothesis. According to
this scenario, the earth experienced a head-on crash with a Mars-
sized body (that's a body about one-ninth the mass of earth and nine
times more massive than the moon). Picture the enormous impact, the
blast of heat and debris. The denser material of the impacting body
would sink into the earth's core. The collision debris would drift
upward to form a huge dust cloud around the earth, a cloud of
material dramatically influenced by the heat of the explosive event. In
time, under the influence of gravity, that dust cloud would coalesce
into a solid body, the moon. The beauty of this hypothesis lies in its
capacity to explain such wonders as the differing composition of the
earth and the moon. Moon rock combines the earth's elements with
elements of the colliding body, both chemically altered by intense
heat. It also provides an explanation for the earth's unusual
atmosphere. If the earth had enjoyed a normal childhood, its
atmosphere would resemble that of its sister, Venus, dominated by a
thick mantle of carbon dioxide. This atmospheric greenhouse would
have boiled away Earth's primordial oceans, driving the surface
temperatures even higher, high enough to melt lead-too hot for life. A
powerful collision, however, would have blasted Earth's original
atmosphere into outer space. The atmosphere forming subsequent to
the collision (from Earth's gases, such as those released by volcanoes)
would be much thinner, permitting both a temperature and chemistry
suitable for life. In analyzing the tidal forces between the earth and
the newly forming moon in this scenario, researchers have found a
plausible explanation for the moon's slow spiral away from the earth.
Again the hypothesis fits. I see yet another beauty in this hypothesis,
the beauty it suggests about God's careful planning for planet Earth as
the home for His splendid plants and animals and humans. The size of
the body colliding with Earth, the nature of the collision, and the
timing of the collision all must be fixed within certain narrow limits or
life on Earth would be impossible. Whether this collision hypothesis is
confirmed or replaced by another, no doubt time and research will
reveal, as always, the signature of divine design." (Ross H.,
"Lunar Origin Update", Facts & Faith, First Quarter 1995.
http://www.reasons.org/resources/FAF/95q1faf/95q1moon.html)

If this was the case,and Hecht J., "The making of a Moon", New
Scientist, Vol 155, No 2093, 2 August 1997, p8, says that despite its
problems this is still the "leading theory", it would have to be a
fantastically fine-tuned impact in order to avoid sterilising the early
earth (since it was thought that life had already formed), and eject
enough matter to form our large moon at the right orbit, at the same
time causing the Earth to tilt by the right angle so that seasons could
begin. All this is thought to be essential to life as we know it.

There is one good reason why God might have intervened supernaturally
to set up our solar system and the earth-moon system, and that is if
He wanted life to originate and survive only on Earth. In that case
He would make natural processes incapable of spontaneously
originating and supporting life, and requiring His supernatural
intervention.

LH>But in biological evolution, we can't yet make detailed empirical
>predictions like that. Some claim that natural processes limit
>evolution to microevolution and that interventions must be necessary
>for macro-changes; others claim that natural processes are
>sufficient for macroevolution. The arguments on both sides are
>"hand-wavy." Hand-wavy arguments are valuable in science, but
>things don't really get resolved until we've got the numbers.

Unfortunately, *no one* within mainstream science is claiming that
supernatural interventions must be necessary for macro-changes. The
rules of materialistic-naturalistic science prevent theistic
arguments from even being considered! For example, when eminent
origin of life researcher Dean Kenyon raised the possibility of
intelligent design, he was promptly removed from teaching duties.

LH>So why do our learning institutions almost universally choose
>macroevolution over progressive creation? Here's where philosophy
>becomes a critical factor.

Agreed. The ruling philosophy in science today is
materialism-naturalism, which rules out apriori any consideration of
God playing any supernatural part in the history of life, and
therefore progressive creation cannot even get on the table.
Remember the National Academy of Sciences, submission that "the most
basic characteristic of science" is "reliance upon naturalistic
explanations."

LH>The three major religious convictions of scientists in our learning
>institutions are Judaism, Christianity, and atheism. There are other
>religions represented, but right now and even more so in the past, those
>three account for the vast majority. For atheists, progressive creation
>isn't an option (unless they want to speculate about meddling space
>aliens). Progressive creationism *is* a viable option for theists. God
>could have intervened miraculously in biological history whenever he
>chose; God has intervened miraculously in human history. So why do so
>many theists choose macroevolution over progressive biological creation?

No doubt there are many theists who choose macroevolution over
progressive biological creation, but overall they are a tiny
minority. The evidence of opinion polls consistently show that the
vast majority of theists either believe in young-earth creation or
old-earth (ie. progressive) creation.

LH>The main reason, I believe, is this: macroevolution maintains
>consistency with the common theistic perspective in the other natural
>sciences --- and particularly the other historical sciences.

Since the natural sciences have an uncompromising committment to
materialism-naturalism, and rule out apriori any consideration of
supernatural intervention, the only common theistic perspective that
exists to any extent within mainstream science is a
theistic-naturalism, ie. a theists who accept in their professional
life all the rules of materialist-naturalist science:

"The power of scientific naturalism in the academic world is so
intimidating, however, that hardly anyone is willing to challenge it.
Theologians (or theistic scientists) survive in academia not by
challenging naturalism with a rival interpretation of reality but by
trying to find a place for theology within the picture of reality
defined by scientific naturalists. They write books with titles like
Religion in an Age of Science (Ian Barbour), Theology for a
Scientific Age (Arthur Peacocke) and Theology in the Age of
Scientific Reasoning (Nancey Murphy). I call this genre "theistic
naturalism," because to accommodate successfully the theists must
accept not just the particular conclusions that scientists have
reached but also the naturalistic methodology that generated those
conclusions." (Johnson P.E., "Reason in the Balance", 1995, p97)

LH>We have good empirical models for how stars form and evolve by natural
>processes. We have good empirical models for how the earth formed and
>developed oceans and an atmosphere by natural processes.

This is disputable-Hugh Ross also says in the above article:

"none of the models depicting how gas and dust clouds condense into
planetary systems produce anything like the earth-moon system"
(Ross H., "Lunar Origin Update", Facts & Faith, First Quarter 1995.
http://www.reasons.org/resources/FAF/95q1faf/95q1moon.html)

I would therefore be interested in learning more about these "good
empirical models for how the earth formed". Are these course-grained
to predict the formation of planets in general, or are they so fine-
grained that they can predict the formation of our particular solar
system and in particular our earth-moon system? Besides, how can
these models be checked against the empirical evidence? The only
solar system we know empirically in any detail is our own solar
system, and for all we know it might be uniquein the whole universe
in its life-supporting properties.

LH>We have good empirical models for how the heavy elements
>necessary for life formed by natural processes. The common
>theistic perspective is that, while God could have formed these
>things miraculously, God chose to use the regular and continual
>operation of his natural laws in order to accomplish these acts.

I have no problem with the idea that God used only the continual
operation of his natural laws in order to accomplish the formation
of the heavy elements. But even this requires and extraordinary
degree of fine-tuning. For example, the matching resonances in the
carbon and oxygen atoms:

"In the carbon atom, the resonance just happens to match the
combined energy of the beryllium atom and a colliding helium
nucleus. Without it, there would be relatively few carbon atoms.
Similarly, the internal details of the oxygen nucleus play a critical
role. Oxygen can be formed by combining helium and carbon nuclei,
but the corresponding resonance level in the oxygen nucleus is half a
percent too low for the combination to stay together easily. Had the
resonance level in the carbon been 4 percent lower, there would be
essentially no carbon. Had that level in the oxygen been only half a
percent higher, virtually all of the carbon would have been converted
to oxygen. Without that carbon abundance, neither you nor I would
be here now. I am told that Fred Hoyle, who together with Willy
Fowler found this remarkable nuclear arrangement, has said that
nothing has shaken his atheism as much as this discovery...he wrote:

`Would you not say to yourself, "Some supercalculating intellect
must have designed the properties of the carbon atom, otherwise the
chance of my finding such an atom through the blind forces of nature
would be utterly minuscule." Of course you would.... A common
sense interpretation of the facts suggests that a superintellect has
monkeyed with physics, as well as with chemistry and biology, and
that there are no blind forces worth speaking about in nature. The
numbers one calculates from the facts seem to me so overwhelming
as to put this conclusion almost beyond question.' (Hoyle F., "The
Universe: Past and Present Reflections", in Engineering and Science,
November 1981, p12. Gingerich O., "Dare a Scientist Believe in
Design", in Templeton J.M, ed., "Evidence of Purpose", 1994, pp24-
25).

LH>Moreover, we believe that God today uses natural processes
>(microevolution) under his providential governance to maintain
>robust and adaptive ecologies. Thus, to many theists,
>macroevolutionary theory seems more consistent with how God
>formed and sustains all the other parts of the natural world.

There is great dispute even within naturalistic science whether the same
natural processes that drive small-scale change (microevolution)
can be extrapolated to explain large-scale change (macroevolution):

"The changes within a population have been termed microevolution,
and they can indeed be accepted as a consequence of shifting gene
frequences. Changes above the species level-involving the origin of
new species and the establishment of higher taxonomic patterns- are
known as macroevolution. The central question of the Chicago
conference was whether the mechanisms underlying microevolution
can be extrapolated to explain the phenomena of macroevolution. At
the risk of doing violence to the positions of some of the people at
the meeting, the answer can be given as a clear, No. (Lewin R.,
"Evolutionary-Theory Under Fire: An historic conference in Chicago
challenges the four-decade long dominance of the Modern Synthesis",
SCIENCE, Vol. 210, 21 November 1980, p883)

LH>That, I believe, summarizes the main perceptions and perspectives of the
>(theistic and atheistic) scientists whom I know personally.

If these theistic and atheistic scientists are all either theistic or
atheistic naturalists, then it is not surprising that they all share
these common naturalistic perceptions and perspectives!

Happy Christmas.

Steve

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