Debating with a creationist is actually really easy, because they
only have a few standard arguments, and haven't come up with any new
cogent ones for some time. These standard arguments have been published
time and time again, and a practiced creationist can handily draw them
like a six-gun at the drop of a hat. All of their arguments are silly
in their wrongness and easily debunked, and if you're prepared in
advance, it's easy to beat down any creationist with a quick verbal
body slam. You're not going to change their mind, since creationists do
not base their opinions upon rational study of the evidence; but you
might help clear things up for an innocent bystander who overhears.
So here are the standard arguments for creationism, and the standard
rebuttals from the scientific consensus, starting with my favorite:
Evolution is just a theory, not a fact.This is an easily digestible sound bite intended to show that evolution
is just an unproven hypothesis, like any other, and thus should not be
taught in schools as if it were fact. Actually, evolution is both a
theory and a fact. A fact is something we observe in the world, and a
theory is our best explanation for it. Stephen Jay Gould famously
addressed this argument by pointing out that the fact of gravity is
that things fall, and our theory of gravity began with Isaac Newton and
was later replaced by Einstein's improved theory. The current state of
our theory to explain gravity does not affect the fact that things
fall. Similarly, Darwin's original theory of evolution was highly
incomplete and had plenty of errors. Today's theory is still incomplete
but it's a thousand times better than it was in Darwin's day. But the
state of our explanation does not affect the observed fact that species
evolve over time.
The next argument you're likely to encounter states that
Evolution is controversial; scientists disagree on its validity.Creationists have latched onto the fact that evolutionary biologists
still have competing theories to explain numerous minor aspects of
evolution. Throwing out evolution for this reason would be like
dismissing the use of tires on cars because there are competing tread
designs. Despite the claim of widespread controversy, no significant
number of scientists doubt either the fact of evolution or the validity
of the theory as a whole. Creationists often publish lists of
scientists whom they say reject evolution. These lists are probably
true. In the United States, the majority of the general public are
creationists of one flavor or another. But the scientific community has
a very different opinion: Most surveys of scientists find that 95 to 98
percent accept evolution just as they do other aspects of the natural
world.
Creationists also argue that
Evolution is not falsifiable, therefore it's not science.One of the fundamentals of any science is that it's falsifiable. If a
test can be derived that, if it were to fail, falsified a proposition,
then that proposition meets a basic test of being a science. Something
that cannot be tested and falsified, like the existence of gods, is
therefore not a science. Creationists accept this to the point that
they use it as an argument against evolution's status as a science.
In fact, evolution could be very easily falsified. Evolutionary
biologist JBS Haldane famously said that a fossilized rabbit from the
Precambrian era would do it. Another way to falsify evolution would be
to test any of the innumerable predictions it makes, and see if the
observation doesn't match what was predicted. Creationists are invited
to go through all the predictions made in the evolutionary literature,
and if they can genuinely find that not a single one is testable, then
they're right.
The next argument to be prepared for is that
Evolution is itself a religion.This argument has become increasingly popular in recent years as
creationists have tried to bolster their own position by decorating it
with scientific-sounding words like intelligent design. And as they try
to convince us that their own position is science based, they
correspondingly mock evolution by calling it a religion of those who
worship Darwin as a prophet and accept its tenets on faith since there
is no evidence supporting evolution. Clearly this is an argument that
could only be persuasive to people who know little or nothing about the
concept of evolution or Darwin's role in its development. This argument
is easily dismissed. A religion is the worship of a supernatural divine
superbeing, and there is nothing anywhere in the theory of evolution
that makes reference to such a being, and not a single living human
considers himself a member of any "evolution church."
Creationists also like to argue that
Evolution cannot be observed.Part of what you need to do to validate a theory is to test it and
observe the results. Although there are evolutionary phenomena that can
be directly observed like dog breeding and lab experiments with fruit
flies, most of what evolution explains has happened over millions of
years and so, quite obviously, nobody was around to observe most of it.
This is true, but it misstates what observation consists of. There's a
lot of observation in science where we have to use evidence of an
event: certain chemical reactions, subatomic particle physics,
theoretical physics; all of these disciplines involve experimentation
and observation where the actual events can't be witnessed. The theory
of evolution was originally developed to explain the evidence that was
observed from the fossil record. So in this respect, every significant
aspect of evolution has been exhaustively observed and documented, many
times over.
One of the most tiresome creationist arguments against evolution tries to claim that
There is an absence of transitional fossils. If the ancestor of the modern horse
Miohippus evolved from its predecessor
Mesohippus,then surely there must be examples of transitional fossils that would
show characteristics of both, or perhaps an intermediate stage. I use
the horse example because the fossil record of horses is exceptionally
well represented with many finds. If evolution is true, shouldn't there
be examples of transitional stages between
Miohippus and
Mesohippus?The creationists say that there are not. Well, there are, and in
abundance. You can tell people that there aren't, but you're either
intentionally lying or intentionally refusing to inform yourself on a
subject you're claiming to be authoritative on. Kathleen Hunt of the
University of Washington writes:
A typical Miohippus was distinctly larger than a
typical Mesohippus, with a slightly longer skull. The facial fossa was
deeper and more expanded. In addition, the ankle joint had changed
subtly. Miohippus also began to show a variable extra crest on its
upper cheek teeth. In later horse species, this crest became a
characteristic feature of the teeth. This is an excellent example of
how new traits originate as variations in the ancestral population.
The layperson need look no deeper than Wikipedia to find a long list
of transitional fossils. But be aware that many species known only from
the fossil record may be known by only one skeleton, often incomplete.
The older fossil records are simply too sparse to expect any form of
completeness, especially if you're looking for complete transitions.
It's not going to happen. However, the theory of punctuated equilibrium
predicts that in many cases there will be no transitional fossils, so
in a lot of these cases, creationists are pointing to the absence of
fossils that evolutionary theory predicts probably never existed.
Here's another creationist argument, and when I first heard it I said "What the heck are they talking about??" It's that
Evolution violates the second law of thermodynamics.The second law of thermodynamics states that there is no reverse
entropy in any isolated system. The available energy in a closed system
will stay the same or decrease over time, and the overall entropy of
such a system can only increase or stay the same. This is an immutable
physical law, and it's true. Creationists argue that this means a
complex system, like a living organism, cannot form on its own, as that
would be a decrease of entropy. Order from disorder, they argue, is
physically impossible without divine intervention. This argument is
easy to make if you oversimplify the law to the point of ignoring its
principal qualification: that it only applies to a closed, isolated
system. If you attempt to apply it to any system, such as a plant,
animal, or deck of cards, you've just proven that photosynthesis,
growth, and unshuffling are impossible too. Organisms are open systems
(as was the proverbial primordial goo), since they exchange material
and energy with their surroundings, and so the second law of
thermodynamics is not relevant to them. Innumerable natural and
artificial processes produce order from disorder in open systems using
external energy and material.
In a related vein, creationists also argue that
Evolution cannot create complex structures with irreducible complexity. This argument was made famous by Michael Behe, an evangelical biochemist, who coined the term
irreducible complexity.Take a complex structure like an eyeball, and remove any part of it to
simulate evolution in reverse, and it will no longer function. Thus, an
eyeball cannot have evolved through natural selection, as a
non-functioning structure would not be a genetic advantage. It seems
like it makes sense at face value, but it's based on a tremendously
faulty concept. Evolution in reverse is not accurately simulated by
taking a cleaver and hacking an eyeball in half. The animal kingdom is
full of examples of simpler eye structures, all of which are
functional, all of which are irreducibly complex, and all of which are
susceptible to further refinement through evolution. For a dramatic
visual example of how irreducible complexity can and does evolve
through gradual refinement, and yet remain irreducibly complex, take a
look at Lee Graham's applet the
Irreducible Complexity Evolver at
http://www.stellaralchemy.com/ice/.
Another effort to fight science using logic states that
It's too improbable for complex life forms to develop by chance.This is the old "747 in a junkyard" argument. How likely is it that a
tornado would go through a junkyard, and by chance, happen to assemble
a perfect 747? The same argument was made centuries ago by William
Paley, except he referred to the exquisite design of a pocketwatch, and
pointed out that such a thing is so complex and delicate that it had to
have been designed from the top down by a creator. This argument is
simply reflective of ignorance of the extraordinary power of
evolution's bottom-up design mechanism. Once you have an understanding
of multigenerational mutation and natural selection, and also
understand how structures with irreducible complexity evolve, there's
nothing unlikely or implausible about evolution at all. In fact,
genetic algorithms (the computer software version of evolution), are
starting to take over the world of invention with innovative new
engineering advances that top-down designers like human beings might
have never come up with. Bottom-up design is not only probable, it's
inevitable and nearly always produces better designs than any
intelligent creator could have.
You should also be prepared to hear that
Evolution cannot create new information.Based on a misinterpretation of information theory, this argument
states that the new information required to create a new species cannot
suddenly spawn into existence spontaneously; new information can only
come from an outside source, namely, an intelligent creator. This
particular argument doesn't go very far, since any genetic mutation or
duplication can only be described as new information. Not all of that
information is good. Most of it's useless, but once in a blue moon you
get a piece that's beneficial to the organism. New genetic information
is observed in evolutionary processes every day.
For a final blow from the logic department, be ready for the argument that
Evolution does not explain some aspects of life or culture.This is an argument which is really just a logical fallacy: that since
evolution does not explain everything, it is therefore entirely false.
Evolutionary biologists are the first ones to stand up and say that
there are still plenty of aspects of life we're still learning about.
That doesn't make the things we've already learned wrong. It's also
increasingly common for creationists to point to things that have
nothing to do with the origin of life and speciation, like the Big Bang
and the age of the earth, and argue that since the theory of evolution
does not explain those things as well, it is therefore false. This is
an even greater logical fallacy. Theories explain only those observed
phenomena they are designed to explain. They are not intended to have
anything to do with stuff they have nothing to do with.
Mon Aug 17, 2009 10:25 pm
