15 Answers to Creationist Nonsense

[Randall Lord]

Part 1

Opponents of evolution want to make a place for creationism by tearing down
real science, but their arguments don't hold up
By John Rennie


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When Charles Darwin introduced the theory of evolution through natural
selection 143 years ago, the scientists of the day argued over it fiercely,
but the massing evidence from paleontology, genetics, zoology, molecular
biology and other fields gradually established evolution's truth beyond
reasonable doubt. Today that battle has been won everywhere--except in the
public imagination.
Embarrassingly, in the 21st century, in the most scientifically advanced
nation the world has ever known, creationists can still persuade
politicians, judges and ordinary citizens that evolution is a flawed, poorly
supported fantasy. They lobby for creationist ideas such as "intelligent
design" to be taught as alternatives to evolution in science classrooms. As
this article goes to press, the Ohio Board of Education is debating whether
to mandate such a change. Some antievolutionists, such as Philip E. Johnson,
a law professor at the University of California at Berkeley and author of
Darwin on Trial, admit that they intend for intelligent-design theory to
serve as a "wedge" for reopening science classrooms to discussions of God.

Besieged teachers and others may increasingly find themselves on the spot to
defend evolution and refute creationism. The arguments that creationists use
are typically specious and based on misunderstandings of (or outright lies
about) evolution, but the number and diversity of the objections can put
even well-informed people at a disadvantage.
To help with answering them, the following list rebuts some of the most
common "scientific" arguments raised against evolution. It also directs
readers to further sources for information and explains why creation science
has no place in the classroom.

1. Evolution is only a theory. It is not a fact or a scientific law.

Many people learned in elementary school that a theory falls in the middle
of a hierarchy of certainty--above a mere hypothesis but below a law.
Scientists do not use the terms that way, however. According to the National
Academy of Sciences (NAS), a scientific theory is "a well-substantiated
explanation of some aspect of the natural world that can incorporate facts,
laws, inferences, and tested hypotheses." No amount of validation changes a
theory into a law, which is a descriptive generalization about nature. So
when scientists talk about the theory of evolution--or the atomic theory or
the theory of relativity, for that matter--they are not expressing
reservations about its truth.

In addition to the theory of evolution, meaning the idea of descent with
modification, one may also speak of the fact of evolution. The NAS defines a
fact as "an observation that has been repeatedly confirmed and for all
practical purposes is accepted as 'true.'" The fossil record and abundant
other evidence testify that organisms have evolved through time. Although no
one observed those transformations, the indirect evidence is clear,
unambiguous and compelling.
All sciences frequently rely on indirect evidence. Physicists cannot see
subatomic particles directly, for instance, so they verify their existence
by watching for telltale tracks that the particles leave in cloud chambers.
The absence of direct observation does not make physicists' conclusions less
certain.

2. Natural selection is based on circular reasoning: the fittest are those
who survive, and those who survive are deemed fittest.

"Survival of the fittest" is a conversational way to describe natural
selection, but a more technical description speaks of differential rates of
survival and reproduction. That is, rather than labeling species as more or
less fit, one can describe how many offspring they are likely to leave under
given circumstances. Drop a fast-breeding pair of small-beaked finches and a
slower-breeding pair of large-beaked finches onto an island full of food
seeds. Within a few generations the fast breeders may control more of the
food resources. Yet if large beaks more easily crush seeds, the advantage
may tip to the slow breeders. In a pioneering study of finches on the
Galápagos Islands, Peter R. Grant of Princeton University observed these
kinds of population shifts in the wild [see his article "Natural Selection
and Darwin's Finches"; Scientific American, October 1991].

The key is that adaptive fitness can be defined without reference to
survival: large beaks are better adapted for crushing seeds, irrespective of
whether that trait has survival value under the circumstances.

3. Evolution is unscientific, because it is not testable or falsifiable. It
makes claims about events that were not observed and can never be
re-created.

This blanket dismissal of evolution ignores important distinctions that
divide the field into at least two broad areas: microevolution and
macroevolution. Microevolution looks at changes within species over
time--changes that may be preludes to speciation, the origin of new species.
Macroevolution studies how taxonomic groups above the level of species
change. Its evidence draws frequently from the fossil record and DNA
comparisons to reconstruct how various organisms may be related.

These days even most creationists acknowledge that microevolution has been
upheld by tests in the laboratory (as in studies of cells, plants and fruit
flies) and in the field (as in Grant's studies of evolving beak shapes among
Galápagos finches). Natural selection and other mechanisms--such as
chromosomal changes, symbiosis and hybridization--can drive profound changes
in populations over time.
The historical nature of macroevolutionary study involves inference from
fossils and DNA rather than direct observation. Yet in the historical
sciences (which include astronomy, geology and archaeology, as well as
evolutionary biology), hypotheses can still be tested by checking whether
they accord with physical evidence and whether they lead to verifiable
predictions about future discoveries. For instance, evolution implies that
between the earliest-known ancestors of humans (roughly five million years
old) and the appearance of anatomically modern humans (about 100,000 years
ago), one should find a succession of hominid creatures with features
progressively less apelike and more modern, which is indeed what the fossil
record shows. But one should not--and does not--find modern human fossils
embedded in strata from the Jurassic period (144 million years ago).
Evolutionary biology routinely makes predictions far more refined and
precise than this, and researchers test them constantly.

Evolution could be disproved in other ways, too. If we could document the
spontaneous generation of just one complex life-form from inanimate matter,
then at least a few creatures seen in the fossil record might have
originated this way. If superintelligent aliens appeared and claimed credit
for creating life on earth (or even particular species), the purely
evolutionary explanation would be cast in doubt. But no one has yet produced
such evidence.
It should be noted that the idea of falsifiability as the defining
characteristic of science originated with philosopher Karl Popper in the
1930s. More recent elaborations on his thinking have expanded the narrowest
interpretation of his principle precisely because it would eliminate too
many branches of clearly scientific endeavor.

[Randall Lord]

part 2

4. Increasingly, scientists doubt the truth of evolution.

No evidence suggests that evolution is losing adherents. Pick up any issue
of a peer-reviewed biological journal, and you will find articles that
support and extend evolutionary studies or that embrace evolution as a
fundamental concept.

Conversely, serious scientific publications disputing evolution are all but
nonexistent. In the mid-1990s George W. Gilchrist of the University of
Washington surveyed thousands of journals in the primary literature, seeking
articles on intelligent design or creation science. Among those hundreds of
thousands of scientific reports, he found none. In the past two years,
surveys done independently by Barbara Forrest of Southeastern Louisiana
University and Lawrence M. Krauss of Case Western Reserve University have
been similarly fruitless.

Creationists retort that a closed-minded scientific community rejects their
evidence. Yet according to the editors of Nature, Science and other leading
journals, few antievolution manuscripts are even submitted. Some
antievolution authors have published papers in serious journals. Those
papers, however, rarely attack evolution directly or advance creationist
arguments; at best, they identify certain evolutionary problems as unsolved
and difficult (which no one disputes). In short, creationists are not giving
the scientific world good reason to take them seriously.

5. The disagreements among even evolutionary biologists show how little
solid science supports evolution.

Evolutionary biologists passionately debate diverse topics: how speciation
happens, the rates of evolutionary change, the ancestral relationships of
birds and dinosaurs, whether Neandertals were a species apart from modern
humans, and much more. These disputes are like those found in all other
branches of science. Acceptance of evolution as a factual occurrence and a
guiding principle is nonetheless universal in biology.

Unfortunately, dishonest creationists have shown a willingness to take
scientists' comments out of context to exaggerate and distort the
disagreements. Anyone acquainted with the works of paleontologist Stephen
Jay Gould of Harvard University knows that in addition to co-authoring the
punctuated-equilibrium model, Gould was one of the most eloquent defenders
and articulators of evolution. (Punctuated equilibrium explains patterns in
the fossil record by suggesting that most evolutionary changes occur within
geologically brief intervals--which may nonetheless amount to hundreds of
generations.) Yet creationists delight in dissecting out phrases from
Gould's voluminous prose to make him sound as though he had doubted
evolution, and they present punctuated equilibrium as though it allows new
species to materialize overnight or birds to be born from reptile eggs.
When confronted with a quotation from a scientific authority that seems to
question evolution, insist on seeing the statement in context. Almost
invariably, the attack on evolution will prove illusory.

6. If humans descended from monkeys, why are there still monkeys?

This surprisingly common argument reflects several levels of ignorance about
evolution. The first mistake is that evolution does not teach that humans
descended from monkeys; it states that both have a common ancestor.

The deeper error is that this objection is tantamount to asking, "If
children descended from adults, why are there still adults?" New species
evolve by splintering off from established ones, when populations of
organisms become isolated from the main branch of their family and acquire
sufficient differences to remain forever distinct. The parent species may
survive indefinitely thereafter, or it may become extinct.

7. Evolution cannot explain how life first appeared on earth.

The origin of life remains very much a mystery, but biochemists have learned
about how primitive nucleic acids, amino acids and other building blocks of
life could have formed and organized themselves into self-replicating,
self-sustaining units, laying the foundation for cellular biochemistry.
Astrochemical analyses hint that quantities of these compounds might have
originated in space and fallen to earth in comets, a scenario that may solve
the problem of how those constituents arose under the conditions that
prevailed when our planet was young.

Creationists sometimes try to invalidate all of evolution by pointing to
science's current inability to explain the origin of life. But even if life
on earth turned out to have a nonevolutionary origin (for instance, if
aliens introduced the first cells billions of years ago), evolution since
then would be robustly confirmed by countless microevolutionary and
macroevolutionary studies.

8. Mathematically, it is inconceivable that anything as complex as a
protein, let alone a living cell or a human, could spring up by chance.

Chance plays a part in evolution (for example, in the random mutations that
can give rise to new traits), but evolution does not depend on chance to
create organisms, proteins or other entities. Quite the opposite: natural
selection, the principal known mechanism of evolution, harnesses nonrandom
change by preserving "desirable" (adaptive) features and eliminating
"undesirable" (nonadaptive) ones. As long as the forces of selection stay
constant, natural selection can push evolution in one direction and produce
sophisticated structures in surprisingly short times.

As an analogy, consider the 13-letter sequence "TOBEORNOTTOBE." Those
hypothetical million monkeys, each pecking out one phrase a second, could
take as long as 78,800 years to find it among the 2613 sequences of that
length. But in the 1980s Richard Hardison of Glendale College wrote a
computer program that generated phrases randomly while preserving the
positions of individual letters that happened to be correctly placed (in
effect, selecting for phrases more like Hamlet's). On average, the program
re-created the phrase in just 336 iterations, less than 90 seconds. Even
more amazing, it could reconstruct Shakespeare's entire play in just four
and a half days.

9. The Second Law of Thermodynamics says that systems must become more
disordered over time. Living cells therefore could not have evolved from
inanimate chemicals, and multicellular life could not have evolved from
protozoa.
This argument derives from a misunderstanding of the Second Law. If it were
valid, mineral crystals and snowflakes would also be impossible, because
they, too, are complex structures that form spontaneously from disordered
parts.

The Second Law actually states that the total entropy of a closed system
(one that no energy or matter leaves or enters) cannot decrease. Entropy is
a physical concept often casually described as disorder, but it differs
significantly from the conversational use of the word.

More important, however, the Second Law permits parts of a system to
decrease in entropy as long as other parts experience an offsetting
increase. Thus, our planet as a whole can grow more complex because the sun
pours heat and light onto it, and the greater entropy associated with the
sun's nuclear fusion more than rebalances the scales. Simple organisms can
fuel their rise toward complexity by consuming other forms of life and
nonliving materials.

10. Mutations are essential to evolution theory, but mutations can only
eliminate traits. They cannot produce new features.

On the contrary, biology has catalogued many traits produced by point
mutations (changes at precise positions in an organism's DNA)--bacterial
resistance to antibiotics, for example.

Mutations that arise in the homeobox (Hox) family of development-regulating
genes in animals can also have complex effects. Hox genes direct where legs,
wings, antennae and body segments should grow. In fruit flies, for instance,
the mutation called Antennapedia causes legs to sprout where antennae should
grow. These abnormal limbs are not functional, but their existence
demonstrates that genetic mistakes can produce complex structures, which
natural selection can then test for possible uses.

Moreover, molecular biology has discovered mechanisms for genetic change
that go beyond point mutations, and these expand the ways in which new
traits can appear. Functional modules within genes can be spliced together
in novel ways. Whole genes can be accidentally duplicated in an organism's
DNA, and the duplicates are free to mutate into genes for new, complex
features. Comparisons of the DNA from a wide variety of organisms indicate
that this is how the globin family of blood proteins evolved over millions
of years.

[Randall Lord]

Part 3

11. Natural selection might explain microevolution, but it cannot explain
the origin of new species and higher orders of life.

Evolutionary biologists have written extensively about how natural selection
could produce new species. For instance, in the model called allopatry,
developed by Ernst Mayr of Harvard University, if a population of organisms
were isolated from the rest of its species by geographical boundaries, it
might be subjected to different selective pressures. Changes would
accumulate in the isolated population. If those changes became so
significant that the splinter group could not or routinely would not breed
with the original stock, then the splinter group would be reproductively
isolated and on its way toward becoming a new species.

Natural selection is the best studied of the evolutionary mechanisms, but
biologists are open to other possibilities as well. Biologists are
constantly assessing the potential of unusual genetic mechanisms for causing
speciation or for producing complex features in organisms. Lynn Margulis of
the University of Massachusetts at Amherst and others have persuasively
argued that some cellular organelles, such as the energy-generating
mitochondria, evolved through the symbiotic merger of ancient organisms.
Thus, science welcomes the possibility of evolution resulting from forces
beyond natural selection. Yet those forces must be natural; they cannot be
attributed to the actions of mysterious creative intelligences whose
existence, in scientific terms, is unproved.

12. Nobody has ever seen a new species evolve.
Speciation is probably fairly rare and in many cases might take centuries.
Furthermore, recognizing a new species during a formative stage can be
difficult, because biologists sometimes disagree about how best to define a
species. The most widely used definition, Mayr's Biological Species Concept,
recognizes a species as a distinct community of reproductively isolated
populations--sets of organisms that normally do not or cannot breed outside
their community. In practice, this standard can be difficult to apply to
organisms isolated by distance or terrain or to plants (and, of course,
fossils do not breed). Biologists therefore usually use organisms' physical
and behavioral traits as clues to their species membership.

Nevertheless, the scientific literature does contain reports of apparent
speciation events in plants, insects and worms. In most of these
experiments, researchers subjected organisms to various types of
selection--for anatomical differences, mating behaviors, habitat preferences
and other traits--and found that they had created populations of organisms
that did not breed with outsiders. For example, William R. Rice of the
University of New Mexico and George W. Salt of the University of California
at Davis demonstrated that if they sorted a group of fruit flies by their
preference for certain environments and bred those flies separately over 35
generations, the resulting flies would refuse to breed with those from a
very different environment.

13. Evolutionists cannot point to any transitional fossils--creatures that
are half reptile and half bird, for instance.

Actually, paleontologists know of many detailed examples of fossils
intermediate in form between various taxonomic groups. One of the most
famous fossils of all time is Archaeopteryx, which combines feathers and
skeletal structures peculiar to birds with features of dinosaurs. A flock's
worth of other feathered fossil species, some more avian and some less, has
also been found. A sequence of fossils spans the evolution of modern horses
from the tiny Eohippus. Whales had four-legged ancestors that walked on
land, and creatures known as Ambulocetus and Rodhocetus helped to make that
transition [see "The Mammals That Conquered the Seas," by Kate Wong;
Scientific American, May]. Fossil seashells trace the evolution of various
mollusks through millions of years. Perhaps 20 or more hominids (not all of
them our ancestors) fill the gap between Lucy the australopithecine and
modern humans.

Creationists, though, dismiss these fossil studies. They argue that
Archaeopteryx is not a missing link between reptiles and birds--it is just
an extinct bird with reptilian features. They want evolutionists to produce
a weird, chimeric monster that cannot be classified as belonging to any
known group. Even if a creationist does accept a fossil as transitional
between two species, he or she may then insist on seeing other fossils
intermediate between it and the first two. These frustrating requests can
proceed ad infinitum and place an unreasonable burden on the always
incomplete fossil record.

Nevertheless, evolutionists can cite further supportive evidence from
molecular biology. All organisms share most of the same genes, but as
evolution predicts, the structures of these genes and their products diverge
among species, in keeping with their evolutionary relationships. Geneticists
speak of the "molecular clock" that records the passage of time. These
molecular data also show how various organisms are transitional within
evolution.

14. Living things have fantastically intricate features--at the anatomical,
cellular and molecular levels--that could not function if they were any less
complex or sophisticated. The only prudent conclusion is that they are the
products of intelligent design, not evolution.
This "argument from design" is the backbone of most recent attacks on
evolution, but it is also one of the oldest. In 1802 theologian William
Paley wrote that if one finds a pocket watch in a field, the most reasonable
conclusion is that someone dropped it, not that natural forces created it
there. By analogy, Paley argued, the complex structures of living things
must be the handiwork of direct, divine invention. Darwin wrote On the
Origin of Species as an answer to Paley: he explained how natural forces of
selection, acting on inherited features, could gradually shape the evolution
of ornate organic structures.

Generations of creationists have tried to counter Darwin by citing the
example of the eye as a structure that could not have evolved. The eye's
ability to provide vision depends on the perfect arrangement of its parts,
these critics say. Natural selection could thus never favor the transitional
forms needed during the eye's evolution--what good is half an eye?
Anticipating this criticism, Darwin suggested that even "incomplete" eyes
might confer benefits (such as helping creatures orient toward light) and
thereby survive for further evolutionary refinement. Biology has vindicated
Darwin: researchers have identified primitive eyes and light-sensing organs
throughout the animal kingdom and have even tracked the evolutionary history
of eyes through comparative genetics. (It now appears that in various
families of organisms, eyes have evolved independently.)

Today's intelligent-design advocates are more sophisticated than their
predecessors, but their arguments and goals are not fundamentally different.
They criticize evolution by trying to demonstrate that it could not account
for life as we know it and then insist that the only tenable alternative is
that life was designed by an unidentified intelligence.

15. Recent discoveries prove that even at the microscopic level, life has a
quality of complexity that could not have come about through evolution.

"Irreducible complexity" is the battle cry of Michael J. Behe of Lehigh
University, author of Darwin's Black Box: The Biochemical Challenge to
Evolution. As a household example of irreducible complexity, Behe chooses
the mousetrap--a machine that could not function if any of its pieces were
missing and whose pieces have no value except as parts of the whole. What is
true of the mousetrap, he says, is even truer of the bacterial flagellum, a
whiplike cellular organelle used for propulsion that operates like an
outboard motor. The proteins that make up a flagellum are uncannily arranged
into motor components, a universal joint and other structures like those
that a human engineer might specify. The possibility that this intricate
array could have arisen through evolutionary modification is virtually nil,
Behe argues, and that bespeaks intelligent design. He makes similar points
about the blood's clotting mechanism and other molecular systems.

Yet evolutionary biologists have answers to these objections. First, there
exist flagellae with forms simpler than the one that Behe cites, so it is
not necessary for all those components to be present for a flagellum to
work. The sophisticated components of this flagellum all have precedents
elsewhere in nature, as described by Kenneth R. Miller of Brown University
and others. In fact, the entire flagellum assembly is extremely similar to
an organelle that Yersinia pestis, the bubonic plague bacterium, uses to
inject toxins into cells.

The key is that the flagellum's component structures, which Behe suggests
have no value apart from their role in propulsion, can serve multiple
functions that would have helped favor their evolution. The final evolution
of the flagellum might then have involved only the novel recombination of
sophisticated parts that initially evolved for other purposes. Similarly,
the blood-clotting system seems to involve the modification and elaboration
of proteins that were originally used in digestion, according to studies by
Russell F. Doolittle of the University of California at San Diego. So some
of the complexity that Behe calls proof of intelligent design is not
irreducible at all.

Complexity of a different kind--"specified complexity"--is the cornerstone
of the intelligent-design arguments of William A. Dembski of Baylor
University in his books The Design Inference and No Free Lunch. Essentially
his argument is that living things are complex in a way that undirected,
random processes could never produce. The only logical conclusion, Dembski
asserts, in an echo of Paley 200 years ago, is that some superhuman
intelligence created and shaped life.

Dembski's argument contains several holes. It is wrong to insinuate that the
field of explanations consists only of random processes or designing
intelligences. Researchers into nonlinear systems and cellular automata at
the Santa Fe Institute and elsewhere have demonstrated that simple,
undirected processes can yield extraordinarily complex patterns. Some of the
complexity seen in organisms may therefore emerge through natural phenomena
that we as yet barely understand. But that is far different from saying that
the complexity could not have arisen naturally.

"Creation science" is a contradiction in terms. A central tenet of modern
science is methodological naturalism--it seeks to explain the universe
purely in terms of observed or testable natural mechanisms. Thus, physics
describes the atomic nucleus with specific concepts governing matter and
energy, and it tests those descriptions experimentally. Physicists introduce
new particles, such as quarks, to flesh out their theories only when data
show that the previous descriptions cannot adequately explain observed
phenomena. The new particles do not have arbitrary properties,
moreover--their definitions are tightly constrained, because the new
particles must fit within the existing framework of physics.

Intelligent design offers few answers. For instance, when and how did a
designing intelligence intervene in life's history? By creating the first
DNA? The first cell? The first human? Was every species designed, or just a
few early ones? Proponents of intelligent-design theory frequently decline
to be pinned down on these points. They do not even make real attempts to
reconcile their disparate ideas about intelligent design. Instead they
pursue argument by exclusion--that is, they belittle evolutionary
explanations as far-fetched or incomplete and then imply that only
design-based alternatives remain.

Logically, this is misleading: even if one naturalistic explanation is
flawed, it does not mean that all are. Moreover, it does not make one
intelligent-design theory more reasonable than another. Listeners are
essentially left to fill in the blanks for themselves, and some will
undoubtedly do so by substituting their religious beliefs for scientific
ideas.

Time and again, science has shown that methodological naturalism can push
back ignorance, finding increasingly detailed and informative answers to
mysteries that once seemed impenetrable: the nature of light, the causes of
disease, how the brain works. Evolution is doing the same with the riddle of
how the living world took shape. Creationism, by any name, adds nothing of
intellectual value to the effort.