| Are
the Methods of Biological Evolution Testable?
Proponents
of evolution often complain of the unequal treatment
that it receives in comparison to other scientific theories.
They point out that theories of gravity, the atom, the
cell etc. are rarely if ever challenged while the opposite
is true of evolution. Why? An obvious starting point
to answer that question is to point out a critical difference.
The others are operational theories of phenomena occurring
at the present time and, therefore, readily studied
and observed; on the other hand evolution is an historical
theory that claims to know how certain events occurred
in the distant past, events that were, obviously, not
observed and cannot be replicated by science. (For example,
scientists cannot make living things.) This critical
difference means that operational theories are verifiable
to a high degree of certainty by scientific testing
while the main claims of evolution are arguably not
testable and, therefore, not verifiable.
That realization has caused more than one scientist
to ask the question, “What do we know
to be true about evolution?” Or put another
way, “What are the facts of evolution?”
In science these questions bring to mind terms such
as “verifiable”, “testable”
and “ potentially falsifiable”. Claims made
by scientists about the origin, operation and structure
of natural systems must be tested in multiple ways by
many scientists to determine their truth or falsity.
Testability, verification, falsification, reproducibility
of results are the central characteristics of the scientific
method. Hypotheses that remain untested after a reasonable
period of time after their formulation should be discarded.
However, the tendency in evolution has been to keep
untestable hypotheses on the front burner until a better
one comes along. If that does not happen, the hypothesis’s
longevity often spanning many generations of scientists
gives it a gravitas that allows it to become part of
the evolutionary culture. If this happens often enough,
a theory is constructed as a collection of related but
untested hypotheses which is defended as being a scientific
theory when in reality it is a myth. This type of theory
fends off all opponents by requiring that they demonstrate
the falsity of hypotheses which in the case of evolution
is impossible because it would require knowledge of
events in the distant past. It is the turning of the
scientific method on its head by basing the acceptance
of hypotheses not on verification via testing but instead
on the lack of falsifying evidence. It is analogous
to a legal trial where the prosecution’s evidence
is presumed true and the defendant is presumed guilty
unless the defense can prove otherwise.
Back
to the original question, “What do we know to
be true about evolution?” Evolutionary scientists
claim that a few processes produced all of life’s
organisms from one ancestral cell. Has that claim been
substantially verified by testing? The processes are
the following:
1) Mutations accumulate to produce major changes in
organisms
2)
Endosymbiotic formation of the eukaryotic cell
3)
According to The National Academy of Science publication
Science and Creationism, complex molecular
systems can be formed in the following way : “Natural
selection can bring together parts of a system for one
function at one time and then, at a later time, recombine
those parts with other systems of components to produce
a system that has a different function.”
4)
Complex anatomical systems can develop by evolving through
of a series of stages, each stage being a completely
functional system, but each being more advanced than
the system from which it evolved.
1)
Mutations Accumulate to Produce Major Changes in Organisms
Darwin’s
gradualistic version of evolution formulated in the
mid-19th century persists to this day. He believed that
a mechanism existed for making small changes in organisms
that would accumulate to produce major change. He had
observed species of finches and believed that the process
that caused the differences in the finches could, given
enough time, produce insects, fish, birds, humans, in
short all of life’s organisms. In his day the
molecular and cellular makeup of organisms was unknown
and, therefore, Darwin was unable to propose what the
mechanism for change might be. That had to wait until
the middle of the 20th century when mutations in the
DNA of reproductive cells were suggested as the means
for producing small changes that could be passed on
to progeny.
This
is the most important hypothesis of evolution---mutations
chosen by a natural selection process have accumulated
over hundreds of millions of years to produce all organisms
from an ancestral cell. This is accepted as fact and
stated without reservation in virtually all presentations
of evolution But has this hypothesis been tested? Can
it be tested? Could it have been tested before DNA was
discovered?
The
Fossil Test
Although Darwin had no knowledge of DNA, he believed
his gradualistic version of evolution would become obvious
once the earth’s sedimentary strata revealed their
fossil content. He believed that all forms of life were
connected by “infinitely numerous transitional
links” with “every stratum full of such
intermediate links”. Obviously if Darwin were
alive today, he would be extremely disappointed by the
fossil record. Hundreds of thousands of fossils have
been collected and not one example exists of features,
such as legs, wings and backbones developing gradually.
Whenever they appear in the fossil record, they are
fully formed. Actually and not unexpectedly, fossils
mimic living organisms in that they do not form a continuum.
Living things are not connected by Darwin’s “infinitely
numerous transitional links” and neither are fossils.
The
paucity of transitional links has caused many evolutionist
to accept a modified, gradualistic version, one that
would not produce many transitional links. The modified
version is called “punctuated equilibrium”.
It hypothesizes that for most of their lifetime organisms
of the past did not change but when they did, they did
it rapidly and the change occurred in small populations.
Therefore, there never were many transitional forms
and that explains their absence from the fossil record.
It could happen like this. Suppose turtles evolved from
a particular group of frogs living in a small pond that
effectively isolated them from other frogs. The mutations
that gave the frogs turtle-like features occurred rapidly
and to at least one frog of each sex who through mating
passed the mutations on to their progeny. Eventually
the Adam and Eve of turtles emerged from the pond and
set forth to populate the earth, and none of the transitional
frog-turtles (frotles?) was preserved as a fossil.
Punctuated
equilibrium was first proposed in the 1970’s and
has become accepted by many evolutionists. Can it be
verified by testing? Obviously not. The evidence for
it is no evidence, namely the absence of transitional
links.
The
DNA Test
How about experimenting with DNA to see if sequences
of changes induced in it will produce major beneficial
changes in organisms? If fossils contained DNA, perhaps
the hypothesis could be tested by comparing their DNA.
But they do not. Experiments on living organisms that
might test the hypothesis are a fool’s errand
because of the enormous complexity of cellular systems.
A single gene can be changed in thousands of ways and
the ramifications of most changes are unknown. The likelihood
that a researcher can induce a sequence of mutations
in succeeding generations of an organism that will provide
beneficial changes, as evolution claims happened innumerable
times in the past, is so small that it stifles attempts
to try it. As a result the mutation hypothesis has not
and cannot be tested by this method. The degree of untestability
is complete applying not only to major changes in organisms
but also to those at the species level. In other words
mutations as the cause of trivial differences such as
that of a gray squirrel and brown one are no more testable
than those of a fish and turtle. That is evident in
the following challenge of Lynn Margulis who is known
for the endosymbiotic model of the eukaryotic cell.
In one of her many public speeches she challenges molecular
biologists to give an unambiguous example of the formation
of a single new species by the accumulation of mutations.
Her challenge goes unmet.1 The mutation hypothesis remains
untested and, if anything, the fossil record shows it
much more likely to be false than true. However, its
150 yearlong existence has elevated it to scientific
fact and its is stated without reservation in countless
textbooks and other expositions of evolution
2)
The Endosymbiotic Formation of the Eukaryotic Cell
The
eukaryotic cell differs from prokaryotes (bacteria)
in that many of its functions are compartmentalized
in small units called organelles. For example, the DNA
is stored in an organelle called the nucleus and the
molecular fuel is produced in organelles called mitochondria.
Since all multi celled plants and animals consist of
eukaryotic cells, the eukaryotic cell is considered
more advanced then the prokaryotic cell and, therefore,
is believed to have evolved from it. But how?
In
the 1970’s Lynn Margulis proposed that eukaryotic
cells resulted from a symbiotic relationship between
two prokaryotic cells. A small prokaryote entered a
larger prokaryote and the smaller one evolved into a
mitochondrion and the larger one evolved all the features
of a eukaryotic cell. Of course, this took a long time,
possibly a billion years and many, many cell divisions.
After being met with initial derision, the hypothesis
was widely accepted as similarities between prokaryotes
and mitochondria became known. For example, both divide;
both contain DNA in ring form; they have similar sizes.
But in spite of these similarities, prokaryotic cells
and mitochondria are vastly different. In addition,
eukaryotic cells are vastly different from prokaryotic
cells.
Here
are a few of the differences between eukaryotic and
prokaryotic cells. Besides the nucleus and mitochondria,
eukaryotic cells have several other organelles. The
endoplasmic reticulum and the Golgi complex are two
large organelles that are active in the synthesis of
many different kinds of proteins. Lysosomes are waste
disposal plants, containing enzymes for dismantling
a variety of cellular fragments. Peroxisomes are more
specialized waste disposal plants. Chloroplasts in plant
cells change light into a chemical fuel.
Because
a eukaryotic cell in comparison to a prokaryote is like
New York City to Small Town, USA, a complex transportation
system exists in the former. This includes a variety
of small vessels that encapsulate and transport cargo
within the cell. In addition molecular motors pull organelles
and molecular fragments along a complex network of filaments
strung across the cell. All this intracellular movement
requires an elaborate mail and address system so that
cargo reaches the correct destination.
Eukaryotic cells also contain a cytoskeleton, a complex
network of three kinds of filaments that gives the cell
some rigidity, compartmentalizes the cell’s interior
and serves as roads in the transportation system. The
filaments are dynamic in that they can disassemble and
reassemble in different places for different purposes
as they do when separating chromosomes during cell division.
Finally since all activities in cells are tightly coordinated,
eukaryotic cells have an enormously complex system that
directs and controls that activity.
Is
Margulis’s hypothesis for the formation of the
eukaryotic cell testable?
Definitely not! Because no scientist is capable of demonstrating
the existence of a sequence of molecular events that
can or did change the prokaryote-cell-within-a-prokaryote-cell
system to a eukaryotic cell. And the profound molecular
differences strongly suggest that it never happened.
As for experimental testing, is anyone foolish enough
to inject a large prokaryote with a smaller one and
expect it to produce a mitochondrion? Yet this untestable
hypothesis appears in biology textbooks as the truth
with no disclaimers.
After
the mitochondrion hypothesis was made, a similar idea
was proposed for the formation of chloroplasts in eukaryotic
plant cells. It suggested that plant cells were formed
by two invasions of smaller prokaryotes into a large
one. The first invasion produced a mitochondrion and
the later invasion by a different kind of prokaryote
produced a chloroplast with the capability of changing
light into a molecular fuel. This untestable hypothesis
is very effectively displayed in biology textbooks with
a series of pictures showing the small cells crawling
inside a larger cell and changing to mitochondria and
chloroplasts.
3) According to The National Academy of Science
publication Science and Creationism, complex
molecular systems can be formed in the following way
: “Natural selection can bring together parts
of a system for one function at one time and then, at
a later time, recombine those parts with other systems
of components to produce a system that has a different
function.”
Of the four hypothesized processes as to how evolution
works, this is probably the most recent. It is a response
to the challenge to evolution by the concept of irreducibly
complex systems as formulated by the biochemist Michael
Behe.2 He demonstrates that many cellular systems are
irreducibly complex, which means they consist of several
complex interdependent parts all of which are necessary
for the system to function. Such systems could not evolve
in a stepwise manner. Behe cites the mousetrap as an
example of a system where all the parts are necessary
for the trap to work. The removal of any part renders
the trap useless. So to explain the existence of such
systems evolutionists are hypothesizing the fantastically
fortuitous scenario of several complex structures evolving
independently for various purposes and then, at a later
time, coming together and changing in just the right
way so that they can function as a unit. This seems
unbelievable but apparently it is believable enough
to some who dare to put it in print. Obviously this
claim is not testable and is not worthy of any scientist
let alone The National Academy of Science.
4)
Complex anatomical systems can develop by evolving through
of a series of stages, each stage being a completely
functional system, but each being more advanced than
the system from which it evolved.
According to The National Academy of Science publication
Science and Creationism eyes evolved in this
manner. It shows a spot of light sensitive cells in
a flatworm evolving into an insect eye with a light
focusing lens which, in turn, evolves into the camera
eye of vertebrates. This is the same explanation that
Darwin used 150 years ago when challenged to explain
how eyes evolved. He can be excused for his simplistic
explanation because a molecular description of vision
was unknown in his day. However, now that it is known,
this kind of anatomical explanation which does not address
the underlying molecular systems is inexcusable. Could
it be that this omission is deliberate? Because such
discussions would reveal the enormous complexity of
these systems and cause people to question an evolutionary
origin? In any event there is no explanation for the
origin of sight that can be verified by testing.
The
analysis of these pivotal hypotheses of evolution, the
ones that claim to explain how it happened, demonstrates
that they do not meet the criteria of being scientific
because they are not testable. Hence they cannot be
verified or falsified. They are beliefs masquerading
as science. They should not be taught in science courses.
But since we have gotten to the regrettable situation
that the teaching of evolution in the public schools
is mandated, the least we can do is provide an accurate
account by telling the bad along with the good. Textbook
presentations are over the top favorable, leaving no
room for doubt that evolution has occurred. They may
be worthy of a shady used car salesman who extols the
positive while consciously hiding the fatal flaws under
the hood but they are not worthy of scientists.
Competing
theories regarding how life came to exist on earth,
such as creationism and intelligent design, have supernatural
aspects. Because of that they should not be taught in
science classes. Evolution has won the day in the courts
because it is the only purely natural theory. However,
being purely natural does not suffice to make evolution
a scientific theory. Only verification by testing of
its central claims can do that. Therefore, evolutionary
scientists should be required to list the truths of
evolution. If they cannot or will not do that, then
they are admitting that evolution is a myth and should
not be taught in science courses in the public schools.
1.
Behe, M. J. Darwin’s Black Box, (New
York: Simon and Schuster, 1996), p. 26.
2.
Ibid., p. 39.
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