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ESSAYS ON ORIGINS:
Natural Selection and Macroevolution
by Dr. David N. Menton, Ph.D.
This version copyright (c) 1994 by:
Missouri Association for Creation
_____________________________________________________________________
[No. 8 in a series] February 1994, Vol. 4, No. 2
_____________________________________________________________________
Darwin's only observable evidence for "evolution in action" was the
great variation that occurs within species of animals and plants under
domestication. Darwin, who knew nothing of genetics, assumed that there
was virtually no limit to this variation among the individuals of a
species, though any breeder could have told him otherwise. In the first
edition of his book _On the Origin of Species_, Darwin said that he had
no difficulty imagining a race of bears entering the water to catch fish
and then slowly developing wider mouths, shorter legs, and longer tails,
until they evolved by chance into the great whales. Thus, Darwin
extrapolated the observable but limited variation, that occurs among the
individuals of a species, into the unobservable evolution of
fundamentally new animals.
Darwin reasoned that if pigeons and dogs can be selectively bred by
man to produce certain desired traits, then nature itself can select for
limitless traits by a process called _natural selection_. While breeders
use intelligence to select for desired traits (such as physical
appearance or strength), nature, in Darwin's view, selects for those
traits that promote survival itself. Since evolution selects by the
simple expedient of life and death, without death there could be no
evolution. On a recent Phil Donahue show, the well-known evolutionist
Carl Sagan said that it took "lots of deaths in order to get us to where
we are now. The secrets of evolution are time and death." Christians
might give some thought to the implications of this for the Gospel of
Jesus Christ.
Darwin saw nature as a very hostile place where there was an
overproduction of animals and a limited supply of food. He believed
this led to a bloody struggle for existence among animals in which only
the most fit survive. Thus, natural selection came to be defined as
_survival of the fittest_. One of the problems with this "explanation"
is that it is a tautology. A tautology is a circular statement such as
"deafness causes loss of hearing" -- while true, it adds nothing to our
understanding. Which animals survive? -- why, those that are fit. What
do we mean by "fit"? -- why, those that survive!
The classical Darwinian view of natural selection as survival of the
fittest was later modified to mean differential reproduction. This
interpretation of natural selection became popular in the 1950's under
the name of neo-Darwinism. In the neo-Darwinian view, nature does not
merely select for animals that survive, but for animals that leave the
most offspring. Think this one through -- according to Darwin the
reason we are supposed to have evolution in the first place is that
animals leave too many offspring, and there isn't enough food to feed
them. Now we are told by neo-Darwinists that the animals that leave the
most offspring insure the continued survival of their species.
Ironically, neo-Darwinists (like Paul Ehrlich), stridently insist that
we humans must severely limit the number of our offspring if our species
is to survive!
Almost all biology textbooks give the example of the peppered moth as
observable evidence of natural selection. Peppered moths of the species
_Biston betularia_ range in color from mostly white with a peppering of
black specks to nearly all black. At one time, the lighter colored
moths of this species were the most numerous because they blended in
with the light-colored bark of the trees they favored, and thus, were
nearly invisible to their bird predators. Several years ago, air
pollution caused the bark of these trees to darken, exposing the lighter
moths to the birds. Naturally, the birds ate the more visible white
variety, leaving behind mostly the darker variety of the species which
lay hidden on the soot-darkened trees. To the evolutionist, this is
observable evidence of evolution in action! But while the peppered
moths are clearly an example of natural selection, they do not show the
evolution of a fundamentally new kind of animal, or even a new species
of moth.
Evolutionists like to refer to the sort of variation we see among
individuals of a species as _microevolution_, implying that this is
somehow related to the chance formation of fundamentally new animals by
a process known as macroevolution. There is, in fact, no known
relationship between so-called microevolution and macroevolution. Most
evolutionists are quite aware of this (although you would never guess it
from the explanations of evolution in the media, textbooks, and in the
classroom). A report in the journal _Science_ (vol. 210 pg. 883-887) on
a recent macroevolution conference held at the Field Museum of Natural
History in Chicago, summarized the views of participating evolutionists
as follows:
"The central question of the Chicago Conference was whether the
mechanisms of microevolution could be extrapolated to explain the
phenomenon of macroevolution. At the expense of doing violence
to the positions of some people at the meeting, the answer can be
given as a clear NO."
If this conclusion alone was shared with students in our schools, it
would go a long way toward addressing the concern that evolution be
critically evaluated in the classroom, rather than dogmatically
indoctrinated.
One of the great achievements of modern science is the discovery of
how it is possible for animals of the same species to show an immense
range of variation without changing into completely different kinds of
animals. Genetic analysis shows that the individuals of a species do
not share an identical set of genes, but rather have a small number of
alternative versions of many genes called _alleles_. Only clones have
the same genes and are essentially identical -- including the same sex.
It would be a boring (and short-lived!) world if all the individuals of
a species were identical clones of one another. The fact that each
individual inherits allelic versions of genes from both parents insures
that no two individuals will be exactly alike. Thus, we say that all
the individuals of a species comprises a _gene pool_ from which
selection (either artificial or natural), can select. The important
point is that we cannot select for genes that are not in the gene pool
of the species.
Consider the remarkable species _Canis familiaris_, which includes
nearly 150 varieties of dogs recognized by the American Kennel Club.
Dogs as different as a 125 pound St. Bernard and a 3 pound Chihuahua are
all the same species of animal! Still, there are limits to what can be
achieved by dog breeders. They can breed for long legs and short legs
(within limits), but they can't breed for a flying dog with wings. The
reason for this is simple: there are no genes in the entire gene pool of
the species _Canis familiaris_ that would produce wings, or any of the
other countless specializations necessary for flight. For this, the
evolutionist must look to _mutations_, their most ludicrous mechanism of
all. We will talk about this in the next installment.
_______________________________________________________________________
Dr. Menton received his Ph.D. in Biology from Brown University. He has
been involved in biomedical research and education for over 30 years.
Dr. Menton is President of the Missouri Association for Creation, Inc.
Originally published in:
St. Louis MetroVoice
PO Box 220010
St. Louis, MO 63122
_______________________________________________________________________
Corrections and revisions have been made by the
author from the original published essay.
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