Christians should not be
afraid of “good” science; that is models and theories about nature that are honestly
based on evidence. We should not simply dismiss evolutionary theory, nor should
we assume we have to rethink our interpretation of the Bible to fit
evolutionary theory. Instead, we should learn the current evidence for the
theory and evaluate it based on this evidence. It is not persuasive to those
that already do not trust the Bible to argue against a scientific theory by
using passages of scripture. As I have argued in past posts (http://natureandscripture.blogspot.com/2014/01/science-christianity-no-conflict.html), we can be confident that when we
interpret both nature and scripture accurately, they will agree; even if we do
the work of evaluating the evidence from nature separate from evaluating the
evidence from scripture. Christians should not be afraid to look honestly at
the evidence regarding evolution.
In my previous post (http://natureandscripture.blogspot.com/2014/02/we-must-understand-it-before-we-argue-it.html), I showed that evolution is a many
faceted term. We need to be specific with our terms when discussing evolution,
as several aspects of the theory are directly observed and therefore
undebatable. For example, natural selection, micro-evolutionary changes, and
speciation are three aspects of the theory that are not in question. In this
post, when I use the term evolution,
I will be referring to the extrapolation of micro-evolutionary changes; termed macro-evolution in the previous post. There
are four areas where the evidence for this extrapolation can be debated: the
fossil record and the explosive nature of innovation, observed limits of
natural selection, conflicting evolutionary trees, and convergence.
The evolutionary theory
of common descent makes the prediction that we should see a gradual progression
from one form of life to another in the fossil record; yet this extrapolation
of microevolution is not confirmed by the evidence in the ground. Charles
Darwin himself wondered, “By this theory innumerable transitional forms must
have existed, why do we not find them embedded in countless numbers in the
crust of the earth?”[1]
The fossil record does not show gradualism.
There is another and allied difficulty, which is much
graver. I allude to the manner in which numbers of species of the same group, suddenly
appear in the lowest known fossiliferous rocks.[2]
Yes, we do find fossils of
transitional forms (defined as an organism that seems to have characteristics
of other organisms found both earlier and later in the fossil record), but what
we overwhelmingly observe in the fossil record is explosive, abrupt appearances
every time there is biological innovation. The history of life on earth is mass
originations coupled with mass extinctions.
The fossil record indicates that prior to about 570 million
years ago life on Earth appears to have been dominated by single-celled
organisms. At that point an event known as the Avalon Explosion took place.
During this origins event, an enigmatic fauna of complex marine creatures known
as the Ediacarans appeared. The Ediacaran fauna consisted of about 270 species that have been recovered as
fossils in about thirty localities around the world. The organisms disappeared
shortly before the Cambrian explosion. New research indicates that Ediacaran
fauna emerged explosively, in the same manner as that of the Cambrian event. During
the Avalon explosion the full range of anatomical characteristics displayed by
the Ediacarans was already expressed around 570 million years ago. In other
words, no evolutionary buildup of biodiversity.
Known in Darwin’s time, the Cambrian explosion refers to the
dramatic appearance of complex animal life in the fossil record about 540
million years ago. Within a short period of time—perhaps less than 5 million
years—anywhere from 50 to 80 percent of all animal phyla to ever exist on Earth
appeared. The animals that came into existence during the Cambrian explosion
were marine creatures. Instead of relatively simple organisms originating at
the base of the Cambrian and then evolving toward increased intricacy, complex
animals appear suddenly. The traditional evolutionary explanation argues that
life should transition from simple to complex in a gradual, branching,
tree-like fashion. On the other hand, such explosive appearances are exactly
what should be expected if a Creator is responsible for orchestrating life’s
history.[3]
A new discovery of
540 million year old fossils in Kootenay National Park[4]
has added more evidence for the explosive nature of the Cambrian period. Twelve
new Cambrian species, including a chordate, have been found so far, as well as
many of the same species as found in a Chinese Cambrian fossil bed. These animals showed up suddenly, were
prolific (because the fossil beds are exceedingly dense), and show a wide
geographic extent (Canada to China). The
Chinese site has identical fossils which are 10-15 million years older, so
there creatures remained the same for that quite a while without any
evolutionary change taking place. Lynn Margulis, American Biologist and 2008 winner
of the Darwin-Wallace Medal (given for major advances in evolutionary biology),
who also happens to be the ex-wife of Carl Sagan, has noticed the same problem.
What you'd like to
see is a good case for gradual change from one species to another in the field,
in the laboratory, or in the fossil record--and preferably in all three.
Darwin's big mystery was why there was no record at all before a specific point
[dated to 542 million years ago by modern researchers], and then all of the
sudden in the fossil record you get nearly all the major types of animals. The
paleontologists Niles Eldredge and Stephen Jay Gould studied lakes in East Africa
and on Caribbean islands looking for Darwin's gradual change from one species
of trilobite or snail to another. What they found was lots of back-and-forth
variation in the population and then--whoop--a whole new species. There is no
gradualism in the fossil record.[5]
Eugene Koonin, an American biologist and Senior Investigator at the National
Center for Biotechnology Information, National Library of
Medicine, National Institutes of
Health notices the same pattern of explosive appearance, followed by
periods of stasis and slow micro-evolution.
Major transitions in biological
evolution show the same pattern of sudden emergence of diverse forms at a new
level of complexity. The relationships between major groups within an emergent
new class of biological entities are hard to decipher and do not seem to fit
the tree pattern that, following Darwin's original proposal, remains the
dominant description of biological evolution. The cases in point include the
origin of complex RNA molecules and protein folds; major groups of viruses;
archaea and bacteria, and the principal lineages within each of these
prokaryotic domains; eukaryotic supergroups; and animal phyla. In each of these
pivotal nexuses in life's history, the principal "types" seem to
appear rapidly and fully equipped with the signature features of the respective
new level of biological organization. No intermediate "grades" or
intermediate forms between different types are detectable.[6]
Not only does the
evidence show explosive appearance, but laboratory evidence seems to be pointing
to a limit to what natural selection and micro-evolution can accomplish. We
have directly observed the HIV virus, the malaria organism, and E. coli
bacteria evolve through countless generations, greatly surpassing the numbers
of mammals that have ever lived in the earth.
The bottom line: Despite huge population numbers and intense
selective pressure, microbes as disparate as malaria and HIV yield similar,
minor, evolutionary responses. Darwinists have loudly celebrated studies of
finch beaks, showing modest changes in the shapes and sizes of beaks over time,
as the finches’ food supplies changed. But here we have genetic studies over
thousands upon thousands of generations, of trillions upon trillions of
organisms, and little of biochemical significance to show for it.[7]
We have directly observed these huge
numbers of populations in the lab under more stress than they would experience
in nature and we have not seen very much cumulative micro-evolutionary changes;
this directly observed lack of variation contributes to the doubt of macro-evolutionary
change.
Common descent also proposes
“evolutionary trees” originally drawn based on how similar body structures are
(morphology). It is assumed that the more similar the structure, the more closely
related the organisms. Evolutionary trees can also be drawn using the DNA; this
assumes that the more closely related organisms are, the more similar their
sequence of genes will be. This creates another place of doubt for the theory
of common decent, as quite often the trees drawn by morphology do not match the
trees drawn by genomic sequence.
In other words, depending on the region of the genome that is selected,
differing “evolutionary trees” result for humans and the great apes. The
evidence does not support a key idea of the evolutionary paradigm; namely, that
evolutionary trees built from separate DNA sequences should agree with each
other and with those constructed from morphology (form).[8]
In conclusion, the biological processes that generate phylogenic
conflict are ubiquitous, and overcoming incongruence requires better models and
more data than have been collected even in well-studied organisms…[9]
Common descent requires that
morphological trees match genomic trees. We continue to find places where this
is not the case, casting doubt on our understanding of macro-evolution. If you
want to read an evaluation of evolutionary trees specifically related to human
evolution, go here: http://www.reasons.org/articles/will-the-real-human-ancestor-please-stand-up
Convergence is the last
line of evidence that can be questioned as to whether it supports the
possibility of common descent. According to current evolutionary theory, convergent
evolution occurs when organisms that evolved independently from different
ancestors adapt to similar environments in similar ways to form analogous
structures or features. There are over 200 examples of biochemical convergence
and numerous examples of homologous convergence.
[Convergence] refers to the
widespread pattern in nature in which unrelated organisms possess nearly
identical anatomical, physiological, behavioral, and biochemical
characteristics. The wings of birds and bats represent one textbook example.
Birds and bats belong to different groups, with birds assigned to the class Aves and bats to the class Mammalia. According to the evolutionary paradigm, undirected
natural processes yielded the identical outcome (wings, in this case) because
the forces of selection channeled evolutionary pathways to the same endpoint.[10]
One of the challenges that convergence creates for the evolutionary
paradigm is the frequency with which it occurs throughout life’s history.
Convergence is a common characteristic of life. This commonness makes little
sense in light of evolutionary theory. If evolution is indeed responsible for
the diversity of life, one would expect convergence to be extremely rare. The
mechanism that drives the evolutionary process consists of a large number of
unpredictable, chance events that occur one after another. Given this mechanism
and the complexity and fine-tuning of biological systems, it seems improbable
that disparate evolutionary pathways would ever lead to the same biological
feature.[11]
The
problem is that we get convergence with vastly different organisms in vastly
different environments! It is hard to explain why different environments would
produce analogous structures in unrelated organisms. An example of this is the
eye structure of cephalopods (squids are a type of cephalopod) and vertebrates
(animals with backbones). The eye would have had to evolve not only in two
fundamentally different groups, but also under totally different selective
forces; aquatic vs. terrestrial. This difference again happens with the sand lance
(a fish) and the chameleon. Again, two totally different groups of animals in two
totally different environments with analogous eyes are not explained very well
with the evolutionary model. Convergence happening in this manner in totally different environments creates
serious doubt for the theory for common descent. If you want to read more about
convergence, go here: http://lukenixblog.blogspot.com/2011/03/can-evolution-repeat.html
While several aspects of evolutionary
theory are not in doubt, there are at least four lines of evidence that raise
serious questions for the extrapolation of microevolution leading to common
descent. We don’t see a gradual progression in the fossil record; instead we
see explosive, dramatic change, followed by periods of slow speciation.
Secondly, we actually observe that there are limits to what natural selection
can do. Thirdly, morphological evolutionary trees often contradict genomic
evolutionary trees. Finally, convergence occurring in vastly different
environments is difficult to explain.
While none of these evidences neither
postulates God, nor disproves evolution, each of them raises doubts and each provides
a place to question evolution within the scope of the science. Evolutionary biologists
themselves will admit that they do not have a complete understanding of
macro-evolution and of the “trees” made to represent common descent; the models
for these two areas are in constant flux and quite often change with a single
fossil discovery. You don’t need to use theology to argue against science, you
can use the evidence from nature itself to engage in discussions about
evolution.
[1]
Charles Darwin, On the Origin of Species.
[2] Ibid.
[3]
Fazale Rana, Ph.D., Reasons to Believe.
[4] http://blogs.scientificamerican.com/symbiartic/2014/02/13/largest-assemblage-of-cambrian-fossils-since-1909-discovered-in-kootenay-national-park/
[6] Eugene
V Koonin, The Biological Big Bang model for the major transitions in evolution, Biology Direct 2007, 2:21, http://www.biology-direct.com/content/2/1/21
[7]
Michael Behe, The Edge of Evolution,
2007, Free Press, New York.
[8]
Dr. Fazale Rana, Reasons to Believe, August
1, 2011, Will the Real Human Ancestor Please Stand Up? http://www.reasons.org/articles/will-the-real-human-ancestor-please-stand-up
[9] Dávalos, L. M., Cirranello, A. L., Geisler, J. H. and Simmons, N. B.
(2012), Understanding phylogenetic incongruence: lessons from phyllostomid
bats. Biological Reviews, 87: 991–1024.
doi: 10.1111/j.1469-185X.2012.00240.x.
[10]
Dr. Fazale Rana, Reasons to Believe, June 19, 2008, Déjá
vu—Again, Part 1 of 2, http://www.reasons.org/articles/deja-vu%E2%80%94again-part-1-of-2
[11]
Dr. Fazale Rana, Reasons to Believe, October
1, 2000, Convergence: Evidence for a Single Creator, http://www.reasons.org/articles/convergence-evidence-for-a-single-creator
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