Any casual observer of nature
recognizes that
many creatures bear some resemblance to
one
another. Many species of frogs, lizards,
fish,
and other animals and plants from
different
parts of the world appear to be nearly
identical. This similarity has been the
pattern
throughout life=92s history. Recent
biological
studies have shed light on the nature of
this
physical resemblance and carry
significant
apologetic implications. Many species
that look
identical are, in fact, genetically
different,
and therefore unrelated. In accounting
for these
unexpected differences, evolutionary
biologists
have proffered inadequate explanations.
This
article will discuss a few of the many
recent
discoveries that continue to buttress
the case
for a biblical creator while continuing
to erode
the foundation for the evolutionary
paradigm.
LifeWay
Recommends |
From
within the highest ranks of the
scientific
community comes a startling new theory
of
creation that not only contradicts
Darwinian
orthodoxy but opens the door to
theological
arguments biologists have dismissed and
ridiculed for more than a century.
'Charmingly
convey(s) a sense of biochemistry's
hidden
beauty'.--'The New York Times Book
Review'. Line
art.
| |
According to evolutionary theory,
organisms
that possess identical morphologies
(forms or
structures) must share a common
ancestry.
Evolutionary biologists, therefore, have
employed morphological
systematicsthe
study of the relationships among
organisms
according to physical
characteristics=when
classifying species, and thus have
concluded
that similar groups share common
ancestry.
However, with the advent and widespread
application of molecular
systematics, in
which DNA sequences are used instead of
morphologies to determine biological
relationships, science now is beginning
to
identify an increasing number of
challenges to
the evolutionary classification.
Biologists are
uncovering numerous examples of
organisms that
cluster together morphologically
(structurally), and yet are
genetically distinct. Frogs,
lizards, or
herbs that appear to be identical are
actually
different at the genetic level. An
evolutionary
interpretation of this data, then,
demands that
the morphologically identical organisms
must
have evolved independently of one
another in
arepeatable fashion.
The Contingent Nature of the
Evolutionary
Process
The evolutionary
paradigm
cannot accommodaterepeatable
evolution. When
evolutionists observe a tree frog
ideally suited
for its environment, they assert that
natural
selection=environmental, predatory,
and
competitive pressures repeatedly
operating on
random inheritable variations for long
periods
of time=has led to this
relationship. Chance
governs the evolutionary process at its
most
fundamental level. Because of this, it
is
expected that repeated evolutionary
events will
result in dramatically different
outcomes.
The concept of Historical Contingency
embodies
this idea and is the theme of Stephen J.
Gould=92s
Wonderful Life:
=85No finale can be
specified at the
start, none would ever occur a second
time in
the same way, because any pathway
proceeds
through thousands of improbable stages.
Alter
any early event, ever so slightly, and
without
apparent importance at the time, and
evolution
cascades into a radically different
channel.{1}
Gould=92s metaphor ofreplaying
life=92s tape
asserts that if one were to push the
rewind
button, erase life=92s history, and let
the tape
run again, the results would be
completely
different.{2}
The very essence of the evolutionary
process
renders evolutionary outcomes as
nonreproducible
(or nonrepeatable). Therefore,
repeatable
evolution is inconsistent with the
mechanism
available to bring about biological
change.
A Test for Evolution, A Test for
Creation
The idea of Historical Contingency
suggests
that one powerful way to discriminate
between
theappearance of design that
results from the
evolutionary process and Intelligent
Design is
to determine if contingency is operating
in the
biological realm.{3}
If life is exclusively the result
of
evolutionary processes, then biologists
should
expect to see few, if any, cases in
which
evolution hasrepeated itself.
This is simply
not the case. During the last six years
numerous
examples ofrepeatable evolution
have come to
light as molecular data has been
increasingly
used in biological systematics. These
findings
demonstrate that the evolutionary
paradigm fails
the test of contingency. The discovery
of
morphologically identical, yet
genetically
unrelated organisms does, however, offer
powerful support for biblical creation.
These
examples ofrepeatable evolution
include
anolis lizards, ranid frogs, cichlids,
sticklebacks, mangabeys, river dolphins,
and
Pericallis, an island plant.
Anolis Lizards
Anolis lizard species found on
the
islands of the Greater Antilles (Cuba,
Hispaniola, Jamaica, and Puerto Rico)
are
perfectly adapted to fit into six
distinctive
ecological niches.{4}
A species that is perfectly suited for a
particular ecological niche is termed an
ecomorph. Two examples of Anolis
lizard
ecomorphs found on the Greater Antilles
are
small lizards with short legs that live
on
fragile twigs, and large lizards with
large toe
pads that occupy the crowns of trees.
Morphological analysis of the
Anolis
lizards that populate the Greater
Antilles
reveals objectively recognizable groups
of
ecomorphs.{5}
Based on their morphological features
(or close
resemblance), members of the same
ecomorph
grouping from the different islands were
found
to be more closely related to one
another than
lizards from the same island.
Given the contingent nature of the
evolutionary process, therefore, it
would be
expected that each ecomorph evolved a
single
time from an ancestral species. Each
ecomorph
produced by a single evolutionary
sequence of
events would have then dispersed among
the
islands of the Greater Antilles.
However, when
this model was tested by comparing
mitochondrial
DNA sequences of the different Anolis
species,
it was discovered that lizards in the
same
ecomorph class were not related to one
another.{6}
This study concluded that it would have
taken at
least 17-19 separate evolutionary
pathways to
produce all the Anolis ecomorphs, if
natural
process evolution was the explanatory
agent.
Commenting on this work, biologists P.H.
Harvey
and L. Partridge, state,It seems
that as the
tape of life has been replayed in
separate
islands, there has been a remarkable
amount of
convergent evolution.{7}
Ranid Frogs
Ranid frogscomprised of over
1000
species=are common throughout the
world. These
frogs have adapted to a wide range of
lifestyles
and habitats. Two of the Ranid
subfamilies, Rhacophorinae (tree
frogs)
and Tomopterninal (burrowing
frogs) are
found both in Madagascar and on the
Indian
sub-continent of Asia. They are
nearly
indistinguishable in their
morphological,
physiological and developmental
characteristics
and form two groups of ecomorphs.
Frogs, specifically, and amphibians,
in
general, cannot migrate through salty
environments. Therefore, it has long
been held,
from an evolutionary standpoint, that
the tree
frogs and burrowing frogs evolved prior
to the
separation of the
Madagascar-Seychelles-Indian
tectonic plate from Gondwanaland (the
earth=92s
one land mass prior to tectonic
separation). It
is believed that this tectonic plate
drifted
away from Gondwanaland about 130 million
years
ago, separated to form Madagascar, and
finally
attached onto Eurasia to form the Indian
sub-continent. Some tree and burrowing
frogs
were passively carried along and became
isolated
from one another.
Nuclear and mitochondrial DNA
analyses of
Madagascar and Indian Ranid frogs
demonstrate,
however, that the evolutionary
explanation is
untenable.{8}
DNA sequence analysis clusters these
ecomorphs
based on geography not
morphological
features. In other words, from an
evolutionary perspective, burrowing
frogs and
tree frogs in Madagascar and India
must
have evolved independently. This
same study
has also identified examples of
repeated
evolution for Ranid ecomorphs located in
Sri
Lanka and India.{9}
Even more amazing, researchers conclude
from the
DNA sequence analysis that the larval
characteristics of several Madagascar
and Indian
ecomorphs are also identical. This means
that
the complex developmental pathways and
larval
lifestyles must have evolved
independently on several occasions to
produce
the same result=if the data
is viewed
from an evolutionary perspective.{10}
Cichlids
Cichlids=freshwater fish that
are widely
diverse in form, color and
habits=are scattered
throughout the Southern Hemisphere. {11}
Numerous examples of cichlid ecomorphs
have been
recognized in lakes Victoria, Malawi and
Tanganyika of East Africa. An
evolutionary
explanation would postulate that each of
the
ecomorphs evolved a single time and then
was
independently isolated in each lake
after water
levels subsided, causing a single lake
to split
into three geographically separated
lakes.{12}
Sequence analysis of mitochondrial
DNA,
however, indicates that the ecomorphs
found in
the three East African lakes must have
evolved
independently, multiple times, assuming
an
evolutionary explanation.{13},{14},{15},{16},{17}
Also, researchers have noted the
independent
emergence of ecomorphs for cichlids in
two lakes
in Cameroon.{18}
Even more striking is the recent
recognition
that multiple independent origins
occurred for
ecomorphs within different regions of a
single
lake, Tanganyika.{19}
That is, from an evolutionary
perspective, some
cichlid species in Lake Tanganyika are
viewed as
separate, morphologically
indistinguishable
species thatevolved in exactly
the same way
multiple times.
Like the cichlids, scientists believe
the
sticklebacks species found in British
Columbia
evolved several times independently to
produce
the same ecomorphs. The same two
stickleback
species, bulky benthic (bottom-dwelling)
feeders
and streamline open-water feeders, live
in
isolated lakes near the Pacific coast of
British
Columbia. The standard evolutionary
explanation
maintains that these two species evolved
from
one marine stickleback species, became
trapped
and isolated in the lakes after sea
levels
changed, and then independently
populated the
lakes.{20}
Mitochondrial DNA analysis provides
results
contrary to the most plausible
evolutionary
explanations.{21}
These results indicate that the
stickleback
species from the same lake have a
greater degree
of genetic similarity than do
morphologically
identical species from different lakes.
From an
evolutionary viewpoint, therefore,
stickleback
ecomorphs in the isolated lakes must
be
the product ofreproducible
evolutionary
events.
A recent breeding experiment affirms
the
previous conclusion.{22}
In a laboratory environment, researchers
discovered that corresponding ecomorphs
from
different lakes attempt to interbreed
with one
another, while eschewing the different
ecomorphs
that share their lakes. This result is
interesting in light of the biological
definition of a species.
Biologically, a
species is considered to be an
interbreeding
population of individuals. The
willingness of
the same ecomorphs from different lakes
to
interbreed points to just how profound
the
similarity is among the stickleback
ecomorphs=both morphologically and
behaviorally.
Mangabeys
Mangabeys are large Old World monkeys
found
in Africa. Morphological similarity has
traditionally led biologists to place
all the
mangabey species into a single genus,
Cercocebus. Baboons, drills,
mandrills,
and geladas are closely related to
mangabeys.
Earlier molecular studies and
mitochondrial DNA
sequence analysis challenged the
morphologically
based classification that places
mangabeys into
a single group.{23},{24}
These studies indicated that the single
mangabey
genus should have been separated into
two
groups, and that the nearly identical
mangabey
morphologies must have evolved
independently two
times. Recent nuclear DNA analyses have
confirmed that mangabey morphology
evolved on
two separate occasions, when viewed from
the
evolutionary paradigm.{25}
These results not only support two
morphologically indistinguishable
genera,
Cercocebus and Lophocebus, but also
indicate
that the strong morphological
similarities of
drills, mandrills and baboons must have
evolved
independently as well. Nuclear DNA
sequence
analysis aligns drills and mandrills
with the
mangabey genus, Cercocebus, and baboons
and
geladas with the mangabey genus,
Lophocebus.{26}
Inspired by the results of the molecular
studies, two biologists have recently
recognized
subtle morphological differences in
dental
features and in the arm and leg bones of
the
Cercocebus and Lophocebus mangabeys.{27}
However, these skeletal and dental
differences
are so slight that without the
supporting DNA
sequence data it is questionable if
these
differences would have been recognized
at all,
let alone accepted as significant.
River
Dolphins
Unlike other marine mammals (whales,
porpoises, and dolphins), river dolphins
live in
freshwater, river environments. There
are four
extant river dolphin species. Three of
these
species live exclusively in freshwater
and one
(the La Plata dolphin) lives both in
estuaries
and coastal waters. The freshwater
dolphins
inhabit the Ganges and Brahmaptura
Rivers of
India, the Yangtze River of China, and
the
Amazon River.
River dolphins share similar and
characteristic morphologies. The most
commonplace view among biologists is
that the
river dolphins emerged from a single
evolutionary pathway. Mitochondrial and
nuclear
DNA sequence analysis now demonstrates
otherwise.{28}
In other words, if the DNA
sequence data
is interpreted within an evolutionary
context,
the four river dolphin species must have
evolved
the same characteristic features
independently
and repeatedly.
Pericallis
Pericallis, a genus of plants
related
to sunflowers, are found in the
Macaronesian
archipelago (Azores, Canary Islands,
Cape Verde,
Madeira and Selvagens) off the west
coast of
Africa.{29}
Of the Pericallis species found
in the
Macaronesian islands, six are woody and
nine are
herbaceous. This is not surprising,
since many
island plants are woody variants of
mainland
herbs or soft-bodied plants.
The most reasonable evolutionary
explanation
for the origin of Pericallis woodiness
is that
it evolved on the mainland and found its
way to
the Macaronesian islands. However,
nuclear DNA
sequence analysis betrays this
explanation by
revealing no genetic similarity. When
examined
employing evolutionary assumptions,
therefore,
the data indicates that Pericallis
woodiness
musthave evolved on at least two
separate
occasions.{30}
Evolutionary Attempts to Account for
Repeatable Evolution
In isolation, each case of
repeatable
evolution can be viewed as an oddity and
poses
no real threat to thetruth of
biological
evolution. However, the many cases of
repeatable evolution=in which
entire
organisms seem to evolve independently
and
reproducibly=simply doesn=92t
follow, given the
nature of the mechanism available to
drive the
evolutionary process, chance. Biologists
who
embrace methodological
naturalism=the notion
that only natural explanations can be
used to
account for phenomena in the physical
and
material world=do indeed regard the
occurrences
ofrepeatable evolution as
unexpected and
remarkable. However, their philosophical
predisposition does not allow them to be
open to
the possibility that a Creator is
responsible
for the repeated occurrences of
ecomorphs found
in nature. These morphologically
indistinguishable, yet genetically
distinct
ecomorphs can be properly considered as
one of
the many fingerprints that the Creator
has left
on His creation. In fact, if a single
Creator
was responsible for life, one could
anticipate
seeing repeated examples of the same
blueprint
throughout the biological realm. One
would
expect that a single Creator would reuse
successful designs over and over
again.
Given the examples cited previously,
evolutionary biologists cannot seem to
account
forrepeatable evolution. One
attempt at
explaining this phenomenon is to
attribute
special capability to the forces
of natural
selection.{31}
Since organisms are perfectly suited for
their
ecological milieu, and therefore more
likely to
survive to reproductive age, it is
thought that
the forces of natural
selection=competitive,
predatory, and environmental
influences=repeatedlychannel
the
evolutionary process down the same
pathway to
produce the same organisms. This
explanation for
recurrent evolution neglects the fact
that
selective forces are nothing more than a
blind
filter. Natural selection can only
operate on
traits made available by random changes
in the
population=92s genetic makeup. It is not
likely
that these changes would be repeatable,
given
the complexity of genomes, nor that they
would
occur in the same historical
sequence.
Additionally, it is unlikely that the
factors
that made up an organism=92s ecology
would be
identical throughout time. Changes to
the
ecological environment in Madagascar,
for
example, would not be identical to the
changes
in the ecological environment in India.
The
components of natural selection are
influenced
by chance and by history. Therefore,
natural
selection would not be expected to guide
separate evolutionary sequences and then
produce
morphological traits in an organism that
somehow
remarkably converge.
One well-known experiment with
bacteria has
led evolutionary biologists to conclude
that
natural selection can direct the
convergence of
features in the evolutionary process.{32}
These experiments demonstrated that
bacterial
populations subjected to identical
environments
achieved similar fitness (a measure of
the
ability of an organism to survive)
regardless of
chance, mutational events, and history.
However,
the conclusion drawn from these
experiments does
not support such a directive role for
natural
selection for two reasons.
First, fitness is different from
morphological characteristics. Fitness
describes
the capability to survive independent of
the
organism=92s features. It is not
surprising that
natural selection converges on optimal
fitness
in mathematical modeling or when
characterizing
the response of bacteria to
environmental
stress. Yet, it does not follow that
convergence
to optimal fitness explains the
improbable
convergence of morphological features.
Second,
what is true for bacterial communities
(single
cell organisms that are morphologically
nondescript, comprised of large
population
sizes, and short generation times) is
not
necessarily true for the advanced
multi-cellular
organisms that have been shown to
display
repeatable evolution.{33}
The population and reproductive
characteristics
of these advanced, complex organisms
preclude
their capability to evolve.
Another attempt to account for
repeatable
evolution within the evolutionary
paradigm is
based on inherent biological and
developmental
constraints.{34}
The idea is that these constraints only
allow
certain variations to occur in the
evolutionary
process. When evolution occurs,
then, it
can only produce a limited number of
ecomorphs,
therefore the same ecomorphs result
repeatedly.
This explanation falls short.
Developmental and
inherent biological constraints would
have no
knowledge of the environmental,
predatory, or
competitive pressures facing the
organism.
Therefore, one would not expect there to
be
ecomorphs. In the face of this
explanation one
must ask,Why do we see organisms
that are
perfectly suited to their ecological
niche? The
universal occurrence of perfect
adaptation is
inconsistent with any limitations on
biological
variation.
Conclusion
Prior to the influence of Charles
Darwin
(Origin of Species was first
published in
1859) scientists viewed the nature of
the
similarities among organisms as due to
the
variation of a fundamental design or
archetype.{35}
Thisblueprint for life was
acknowledged as
having come directly from the mind of
God.
Organisms classified within a particular
grouping were viewed as variations of
the design
provided by the Creator.
When the tide began to shift toward
Darwinian
evolution, however, biologists came to
understand the relationships among
organisms as
reflecting descent with modification
from a
common ancestor. The ancestral species
that gave
rise to a group of related organisms
replaced
the archetype, and natural selection
operating
on random biological variation replaced
the
creative hand of God.
As both evolutionists and
creationists seek
to account for the features found in the
biological realms, different predictions
flow
consequentially from these explanations.
Chance
and a historical sequence of events
control
biological evolution, at its essence.
One would
expect therefore, few, if any, instances
in
which the evolutionary process would
repeat
itself. On the other hand, if a single
Creator
were responsible for life on earth, one
would
expect to see recurrent design
throughout
nature.
The widespread availability of
molecular
systematics now allows scientists to
test these
two interpretations of nature. As
molecular
systematics is used increasingly to
characterize
the relationship among
organisms=both living
and extinct=numerous examples of
morphologically identical and
genetically
distinct groups are being uncovered. The
widespread occurrence of repeatable
evolution
cannot be accommodated within the
evolutionary
paradigm. Any attempt to account for
this
phenomenon from a naturalistic
standpoint
violates the very nature of the
evolutionary
process or has implications that are
inconsistent with what biologists
observe in
nature.
The evolutionary paradigm fails in
the face
of the discovery ofrepeatable
evolution while
biblical creation gains support from
this
phenomenon. What is interpreted as
repeatable
evolution=morphologically
indistinct and
genetically unique organisms is
what one would
expect if a single Creator has generated
life
throughout earths history. As time
goes on,
scientists expect to see more examples
of
repeatable evolution. Each new
discovery of
this phenomenon weakens the evolutionary
paradigm and strengthens the case for
creation.
References
- Stephen
J. Gould,
Wonderful Life: The Burgess Shale and
the
Nature of History (New York, NY:
W.W. Norton
& Company, 1989), 51.
- Gould,
48.
- John
Cafferky,
Evolution=92s Hand: Searching for the
Creator
in Contemporary Science (Toronto,
Canada:
East End Books, 1997,) 66-69.
- Jonathan
B. Losos and
Kevin de Querioz,arwins
Lizards, Natural
History, December /January,
(1997/1998):
34-37.
- Jonathan
B. Losos, et
al.,Contingency and Determinism in
Replicated
Adaptive Radiations of Island
Lizards,
Science 279 (1998):
2115-2118.
- Losos, et
al.,
2115-2118.
- Paul H.
Harvey and
Linda Partridge,9ifferent Routes to
Similar
Ends, Nature 392 (1998):
552-553.
- Frankly
Bossuyt and
Michel C. Milinkovitch,Convergent
Adaptive
Radiations in Madagascar and Asian Ranid
Frogs
Reveal Co-Variation Between Larval and
Adult
Frogs, Proceedings of the National
Academy
of Sciences, USA 97 (2000):
6585-6590.
- Bossuyt
and
Milinkovitch, 6585-6590.
- Bossuyt
and
Milinkovitch, 6585-6590.
- Melanie
L.J.
Stiassny and Axel Meyer,Cichlids of
the Rift
Lakes, Scientific American,
February
(1999): 64-69.
- Erik
Verhegen et.
al.,Mitochondrial Phylogeography of
Rock-Dwelling Cichlid Fishes Reveals
Evolutionary Influence of Historical
Lake Level
Fluctuations of Lake Tanganyika,
Africa,
Philosophical Transactions of the
Royal
Society of London B 351 (1996):
797-805.
- Stiassny and Meyer,
64-69.
- Verheyen et al.,
797-805.
- Axel
Meyer et. al.,
Monophyletic Origin of Lake Victoria
Cichlid
Fishes Suggested by Mitochondrial DNA
Sequences, Nature 347 (1990):
550-553.
- John C.
Arise,
Flocks of African Fishes,
Nature 347
(1990): 512-513.
- Axel
Meyer,
Phylogenetic Relationships and
Evolutionary
Processes in East African Cichlid
Fishes,
Trends in Ecology and Evolution 8
(19):
279-284.
- Ulrich
K.
Schliewen, et. al.,Sympatric
Speciation
Suggested by Monophyly of Crater Lake
Cichlids,
Nature 368 (1994): 629-632.
- Lukos
Ruber et.
al.,Replicated Evolution of Trophic
Specializations in an Endemic Cichlid
Fish
Lineage from Lake Tanganyika,
Proceedings of
the Natural Academy of Sciences, USA
96
(1999): 10230-10235.
- Elizabeth Pennisi,
Nature Steers a Predictable
Course,
Science 287 (2000): 207-208.
- Eric B.
Taylor and
J.D. McPhail,Evolutionary History of
an
Adaptive Radiation in Species Pairs of
Threespine Sticklebacks
(Gasterosteus):
Insights from Mitochondrial DNA,
Biological
Journal of the Linnean Society 66
(1999):
271-291.
- Howard
D. Randle,
et. al.,Natural Selection and
Parallel
Speciation in Sympatric Sticklebacks,
Science 287 (2000): 306-308.
- John E.
Cronin and
Vincent M. Sarich,Molecular Evidence
for Dual
Origins of Mangabeys Among Old World
Monkeys,
Nature 260 (1976): 700-702.
- Todd R.
Disotell,
et. al.,Mitochondrial DNA Phylogeny
of the Old
World Monkey Tribe Papionini,
Molecular
Biology and Evolution 9 (1992):
1-13.
- Eugene
E. Harris
and Todd R. Disotell,Nuclear Gene
Trees and
the Phylogenetic Relationships of
Mangabeys
(Primates: Papionini), Molecular
Biology and
Evolution 15 (1998): 892-900.
- Harris
and
Disotell, 892-900.
- John G.
Heagle and
W. Scott McGraw,Skeletal and Dental
Morphology
Supports Diphyletic Origins of Baboons
and
Mandrills, Proceedings of the
National Academy
of Sciences, USA 96 (1999):
1157-1161.
- Insa
Cassens et.
al.,Independent Adaptation to
Riverine
Habitats Allowed Survival of Ancient
Cetacean
Lineages, Proceedings of the National
Academies
of Sciences, USA 97 (2000):
11343-11347.
- Kathryn
S. Brown,
Why Woodiness?, Natural History,
December/January (1999/2000): 74-77.
- Jose L.
Panero, et.
al.,Molecular Evidence for Multiple
Origins of
Woodiness and a New World Biogeographic
Connection of the Macroneasian Island
Endemic
Pericallis (Asteraceae: Senecimeae)
Proceedings
of the National Academy of Sciences, USA
96
(1999): 13886-13891.
- Losos,
et. al.,
2115-2118.
- Michael
Travisano
et. al.Experimental Test of the
Roles of
Adaptation, Chance and History in
Evolution,
Science 276 (1995): 87-90.
- Hugh
Ross,How
SpeciationRules Rule Out
Darwinism, Facts
for Faith 1, no. 2 (2000): 56-57.
- David
B. Wake,
Homoplasy: The Result of Natural
Selection, or
Evidence of Design Limitations?,
American
Naturalist 138 (1991): 543-567.
- Michael
Denton,
Evolution: A Theory in Crisis (Bethesda,
MD:
Adler & Adler, 1985,) -117.
|