Misconceptions
about the Nature of Science
Misconception:
“if you believe in evolution, you can’t believe in God”
First, evolution is not something one “believes in.” Biologists
do not believe in evolution; rather, they accept it as the best explanation
for the diversity and unity of biological organisms.
Second, this is a false dichotomy. Evolutionary theory does not invoke
God as an explanation for the adaptation of organisms. What this means
is that it is not necessary to invoke God as an explanation, but this
is not the same as saying that God does not exist, or that God is impossible.
Evolution does not imply this at all. Science is neutral to God; God
is neither required nor eliminated by scientific explanations. Nothing
about evolution precludes or disproves the existence of God. Science,
as a discipline, cannot address the question of the existence of God,
since science provides natural explanations for natural phenomena, and
God is supernatural.
Furthermore, many evolutionary biologists are devout members of their
religious faith, which comprise all of the world’s major religions.
Indeed, most religions accept that evolution does not conflict with
their religious beliefs (see Voices
for Evolution, National Center for Science Education).
Misconception:
“evolution means that there is no purpose to life”
Again, science cannot address this question (see above). Unfortunately,
some scientists have used their scientific status to postulate that
there is no purpose to life; however, these are their own personal beliefs,
and not scientific opinions. Science can only describe how the world
is; not how the world should be. Also see The
Limits of Science.
Misconception:
“evolution is just a theory”
What is really meant by this is that “evolution is just a guess.”
This is a misunderstanding based on the difference between the scientific
definition of theory and the colloquial use of theory. In common usage,
a theory means a guess, and it is used when someone is taking a guess
about a causal explanation. In science, however, a theory is as big
as it gets. A scientific theory is a coherent body of interconnected
statements, based on reasoning and evidence, which explains a variety
of observations. Because a theory is a complex of interconnected statements,
it does not stand or fall based on a single critical test. In science,
specific hypotheses are tested within an explanatory theoretical framework,
and if continuously supported, are added to that framework. Also see
The Nature of Science.
Describing evolution as “just a theory” also undermines
all of the other major scientific theories (the theory of relativity,
the theory of plate tectonics, the theory of quantum mechanics, the
theory of gravity, etc.). Evolution is arguably the most well supported
theory in all of science. Also see Craig Nelson’s article: Effective
strategies for teaching evolution and other controversial topics in
The
Creation Controversy and the Science Classroom, NSTA.
Misconception:
“evolution hasn’t been proven,” or “prove evolution
to me”
These are meaningless statements. Gravity has never been proven either.
Neither have cells, nor electricity. Evolution cannot be “proven”
because it is a scientific theory. All ideas in science are accepted
tentatively, with the understanding that eventually, with new evidence,
they may be overturned. Evolution is extremely well accepted in the
scientific community because of the vast amount of evidence that has
been put forward for it (many, many examples, from many different biological
disciplines), and the absence of any evidence against it. Because of
the sheer quantity of evidence for evolution, it is extremely unlikely
that it will ever be overturned. Also see The
Evidence for Evolution.
Misconception:
“no one was there to see the origin of life, so any ideas about
it are just a guess”
First, evolutionary theory does not specifically address the origin
of life, but the origin of species. In fact, many argue that a discussion
of evolution should not include the origin of life, since this issue
deals with prebiotic events, and has little to do with biological evolution.
Second, it is true that no one was there to see the origin of life.
This speaks to a larger question about methods used in the historical
sciences. So how do we know anything about the past? Clues to the past
are always left behind. This is how detectives figure out how a crime
was committed, even if there were no eyewitnesses. Scientists use clues
left in the fossil record, for example, to make inferences about biological
history. Scientists’ ideas about the past are based on evidence;
they are not “just a guess” (see “evolution
is just a theory” above).
Misconception:
“science cannot explain X , therefore evolution must be false,
and creationism true”
There is a huge difference between something that is unexplained by
science, and something that science is unable to explain. This argument,
called the “God of the gaps” approach by philosophers, has
been used countless times for phenomena that were as yet unexplained
by science, but for which scientific explanations were eventually found.
This line of thinking sets up a dichotomy between science and religion.
It implies that if science cannot explain X , then God must be responsible
for it. This argument is harmful to religion, and has been rejected
for more than a century by most theologians. Following this line of
reasoning, when science eventually finds an explanation for X , then
that must mean that God had nothing to do with it. This is bad for religion,
and most religious leaders find it to be an ineffective route to faith.
This also illustrates a common tactic used by professional creationists.
Rather than put forward positive evidence for their own ideas, they
try to discredit evolution, and then claim you must then accept creationism.
However, even if evolution were disproved some day, creationism is not
the only other option (see “you should
just teach creationism, too” below).
Misconception:
“Darwin recanted his belief in evolution on his deathbed”
First, Darwin did not “believe in” evolution; he was convinced
by the evidence he uncovered that it was the best explanation for the
origin of species. Second, Darwin’s family denies he recanted
his acceptance of evolution. Third, even if he had recanted, it would
mean absolutely nothing for evolutionary theory. Darwin was the “father”
of the field of evolutionary biology, but he was not the first to discover
evolution. Several others had proposed the general idea of evolution
before Darwin (e.g. Lamarcke). Darwin’s contribution was to: 1)
gather a lot of evidence for evolution (i.e. shared ancestry), and 2)
describe the first plausible mechanism of evolution (natural selection).
In addition, a lot of work has been done in the past century and a half
to add to and modify his ideas into the explanatory framework that evolutionary
theory is today. Scientists do not blindly accept evolution because
Darwin “said so;” they accept it based on the overwhelming
evidence for evolution, and the absence of any evidence against it.
Misconception:
“evolution is racist/sexist/elitist/etc.”
All of the ideas that have been promoted in the name of evolution and
Darwinism actually pre-date Darwin by centuries. Therefore, evolution
and Darwinism are not the cause of these ideas. Darwin himself was very
opposed to slavery. After Darwin’s ideas about natural selection
were widely known, some people used their very naïve and incorrect
interpretation of the scientific ideas to justify their political and
social beliefs (e.g. Social Darwinism). They claimed that some races,
for example, are biologically superior and more “fit” than
others (the Nazis, for example, used these arguments). They justified
their beliefs by claiming they were “natural.” However,
this is the philosophical fallacy called naturalism: claiming that what
is natural is good. In other words, “what is, is what ought to
be.” There is no philosophical foundation to naturalism (see Robert
Pennock’s book: The Tower of Babel).
The philosophy underlying social Darwinism is very different from biological
evolution. On the contrary, evolution unites all of humankind: we are
all related through common ancestry. In fact, evolutionary biologists
have revealed through genetic studies that there is no biological basis
for the concept of race in humans (see Joseph Graves’ book: The
Emperor’s New Clothes).
There is, in fact, an extremely important social role of evolution.
Evolutionary theory forms the basis and the foundation of medical and
biotechnology, agriculture, conservation of species and wildlife management,
and many other fields of increasing importance to society (see Applied
Evolution).
Misconception:
“you should just teach creationism, too”
This is a very popular argument, even with people who do not identify
themselves as creationists, since it appeals to the American sense of
fairness. However, the courts have continuously ruled creationism/creation
science to be a religious view, and not a science (see NCSE’s
“Eight
Significant Court Decisions” by Molleen Matsumura).
As such, they violate the Establishment Clause of the First Amendment,
which protects our freedom to practice the religion of our choice, without
having the state force a particular religion on us. Creation science
cannot, therefore, be taught as science in public schools
.
Even if we could teach creationism in public schools, which type of
creationism should we teach? There are many different types of creationism
(see Eugenie Scott’s Creation/Evolution
Continuum),
as well as hundreds of different creation stories from various cultures
and religions. Should we also teach about the Raëlian view that
intelligent aliens created life on earth? Which explanation (theory)
for the origin of species we teach is based on how successful it is
in its ability to explain the available evidence. It is not based on
which explanation is more popular with the general public. We have a
responsibility to teach how the world is, not how we might like it to
be.
Misconceptions about Evolutionary Concepts
Misconception:
“evolution violates the second law of thermodynamics”
The second law states that closed systems tend toward increased entropy
(or disorder) over time. First, evolution does not always increase complexity.
The evolutionary loss of a trait is quite common (e.g. the loss of eyes
in cave-dwelling animals; the great reduction of the digestive system
in parasitic worms, etc.). Second, the earth and the organisms on earth
are not closed systems, they are open (there is an influx of energy
from the sun, from organisms eating other organisms, etc.). Since they
are open (not closed) systems, the evolution of living organisms does
not violate the second law of thermodynamics.
Misconception:
“where are the missing links?”
When Darwin proposed his theory, he did it in spite of the fossil record,
not because of it. This was because there were major gaps in the fossil
record in the 19th century; the record did not show many transitional
organisms. Since Darwin’s time, many more fossils have been found,
including transitional organisms. As the paleontological record has
developed, it continues to support evolutionary theory. For example,
there are now transitional fossils between fish and amphibians, amphibians
and reptiles, reptiles and mammals, and reptiles and birds.
The fossil record will never be complete (although it is getting more
and more complete every day) because a special set of circumstances
is required for fossilization. Many organisms did not live (or die)
in an environment where they were likely to be fossilized, and organisms
without hard, bony parts are very unlikely to be fossilized at all.
On the other hand, organisms with skeletons are likely to be preserved,
and we expect to find at least some of them in the fossil record.
It is also important to remember that not all fossils are ancestors.
When creationists talk about transitional fossils, what they are really
talking about is ancestry—but no one is suggesting that we have
found a direct line to primitive ancestors. Extinction breaks the chain.
Most species that have ever existed are extinct and much of what we
see is probably collateral kin (i.e. other branches of the tree) rather
than lineal kin. If we HAD a full fossil record, we could reconstruct
all ancestry with relative certainty, but it is hard to reconstruct
the tree without all the pieces. But the parts of the fossil record
that have been discovered do show transitional organisms, and do support
evolutionary theory.
Misconception:
“evolutionists cite homology as similarity due to common ancestry,
then claim it as evidence for common ancestry—a circular argument”
This argument, as stated, is indeed circular. However, an understanding
of the historical development of the idea of homology shows that it
is not a circular argument. Homology is now defined as similarity due
to common ancestry. This is a current definition. Originally, homology
was just a pattern that required an explanation. The pattern of homology
is when a trait is similar in two different species, even if it is not
functionally necessary for them to be similar. The best explanation
for homologies is common ancestry. In addition, even now, it is not
just assumed that two similar traits are homologous (or similar due
to common ancestry). This is a hypothesis that requires testing. Also
see The Evidence for Evolution (Similarity).
Misconception:
“evolutionists cite similarity of vertebrate embryos as evidence
for evolution, even though those drawings are faked”
Vertebrate embryos do have similar features during the early stages
of development. For example, we all have tails and gill pouches, even
if those characteristics are lost later in development. The best explanation
for similarity in early embryos is a shared ancestry of all vertebrates.
Also see The Evidence for Evolution
The problem that creationists picked up on and are using to try to debunk
evolution, is that many textbooks today still use drawings done by Haeckel,
an early embryologist. Haeckel’s drawings (which were meant to
illustrate his idea of “ontogeny recapitulates phylogeny”)
were indeed inaccurate (he drew them from memory). Regardless, the textbooks
that still use this drawing today do not typically use it to illustrate
similarity of embryos as evidence for evolution, but to illustrate von
Baer’s law, which is that general features of a group appear early
in development while specialized features appear later.
Misconception:
“evolution means people come from apes/monkeys/etc.”
First of all evolutionary biology is concerned with the history of all
organisms, not just humans (which is a particularly well studied organism).
Second, we don’t “come from apes,” we share a common
ancestor with the great apes (gorillas, chimps, orangutans, etc.). Since
the great apes are still around today, by definition, they cannot be
our ancestors. Evolution does say that we share an ancestor with the
apes. It also says that we are more closely related to apes than we
are to horses or ferns or bacteria (i.e. we share a more recent common
ancestor with apes, and chimpanzees in particular, than we do with other
organisms). Also see Human Evolution
Misconception:
“complex organs (like the human eye) cannot be produced by chance,
they must have been designed”
This is the classic argument from design; however, it is based on an
incomplete understanding of the mechanisms of evolution. Evolution is
not random; adaptations are not produced by “chance.” Mutation
does produce random (chance) variation, and if mutation were the only
mechanism of evolutionary change, it would be a random process. However,
natural selection, a nonrandom process, acts on this random variation
to produce adaptations like the eye.
Likewise, irreducible complexity arguments state that complex organs
are “irreducibly complex,” you cannot take away one of the
“parts” and still have a functional organ, therefore, it
must have been made all at once. Evolution by natural selection does
not make a complex organ all at once. They are the products of many
small changes (produced by mutation) that are selected for, modified,
and that accumulate over a long period of time. Each of the intermediate
steps is functional. For example, there are many gradations in light-sensing
organs, from the very simple to the very complex (vertebrate and molluscan
eyes), and each of these serves an adaptive function for the organism.
See Kenneth Miller’s book: Finding
Darwin’s God for an excellent analysis of design and irreducible
complexity arguments.
You may also hear probability arguments, in which an astronomically
small probability is stated that some trait evolved by natural causes.
Again, these arguments are based on the assumption that the trait appeared
in its current modern form all at once. Indeed, this would be highly
improbable. However, this is not the way evolution works. Evolution
by natural selection is a gradual, step-by-step process, with incremental
changes occurring through mutations that are then selected for if advantageous.
Misconception:
“microevolution (or limited change within a species) has been
observed, but this has nothing to do with macroevolution (speciation,
etc.)”
The difference between microevolution and macroevolution is only a matter
of degree. The same exact genetic mechanisms act at both scales. Given
enough time, microevolutionary processes (mutation, natural selection,
genetic drift, etc.), produce enough change between two populations
of the same species that they are considered two separate species. Studies
of natural populations have shown current rates of microevolutionary
changes that are orders of magnitude faster than what is typically found
in the fossil record. The distinction between microevolution and macroevolution
is descriptive (e.g. how patterns are described) and not mechanistic
(e.g. how those patterns came about).
Misconception:
“survival of the fittest”
This is a very common misconception about natural selection. Fitness,
as used by evolutionary biologists, is a measure of the relative success
of one genotype over another (in a particular environment). The fitness
of a genotype is a function of the survival rate of all individuals
with that genotype, as well as the average reproductive success (i.e.
the fecundity) of all individuals with that genotype. So, rather than
“survival of the fittest,” it is more like: “the fittest
genotype is the one in which individuals with that genotype have a higher
survival rate and have lots of kids who survive.” Not as catchy.
References
Used
Misconceptions about the Nature of Science