Encyclopedia of Evolution.pdf - Online Reading Center

tain features are universally recognized by scientists, some of
which are presented here.
Science investigates only physical causation and occurrences.
This does not mean that scientists believe only in
physical processes. Many scientists are religious people (see
essay, “Can an Evolutionary Scientist Be Religious?”). However,
scientists do not introduce non-physical causation into
scientific explanations or investigation (see figure at right).
Scientists recognize that science is one way of knowing—a
very powerful and successful way, but not the only way. As
paleontologist Stephen Jay Gould frequently pointed out,
science has been extremely successful at explaining how the
world works and how it evolved but is not always very useful
in helping to generate values and ethics. It is just not designed
to do that. Perhaps it may have been said best by the astronomer
Galileo: Science tells humans “how the heavens go, not
how to go to Heaven.” Scholars may use the scientific method
to investigate the reliability of religious texts, or the mental
basis of religious experience (see religion, evolution of),
but usually do not presume to use science as a basis for their
religious experiences. Therefore, most scientists dismiss the
recent intelligent design challenges to evolutionary science
because the Intelligent Designer, admitted by everyone to be
a supreme supernatural being, cannot “itself” be investigated
scientifically. Belief in a supreme spiritual being is, as it has
always been, a legitimate human activity, but it is not science.
In this way, as in many others listed below, the scientific
method is useful only because of its limitations. If science tries
to be everything, it will end up being nothing. If no physical
explanation is possible, the scientist concludes that he or she
does not have a scientific explanation—even if he or she privately
believes a religious explanation.
Some scholars (see Wilson, Edward O.) have attempted
to bring ethical and religious concepts into a unified field
of scientific knowledge, an approach that Wilson calls consilience.
At the present time, however, this concept has not
gained universal acceptance.
Science investigates only repeatable occurrences. This is
the principal reason that science is limited to physical processes
and data. Miracles happen only once; or, if they happen
more than once, they cannot be counted on to happen
on any investigable schedule. Some creationists claim that
creation science is scientific in the same sense that forensic
science is scientific. The occurrences of murder are unique
and unpredictable, but forensic science can investigate them.
However, this reasoning is invalid. Forensic science is based
upon facts and processes that are well understood from many
repeated observations: regarding rates of bodily decomposition,
symptoms of trauma, the physics of footprints, etc. No
such database exists for the results of miracles.
Scientific research tests hypotheses. This is probably the
main feature that distinguishes science from other approaches
to knowledge. Scientific research poses statements that can
be tested—that is, for which a clear answer can be obtained.
It is the testing of specific hypotheses that distinguishes science
from a mere “walk in the woods,” in which everything
is observed, or the accumulation of knowledge for its own
sake. Scientific observations and measurements are directed
scientific method
This cartoon illustrates what makes scientific inquiry different from other
“ways of knowing.” (Courtesy of Sidney Harris)
toward testing hypotheses. The scientific method can take
idle speculation and turn it into an investigation that yields
a clear answer—an answer to a testable hypothesis. Scientists
usually try to keep hypotheses as simple as possible, in order
to test them easily and clearly.
The scientific method of hypothesis testing need not be
restricted to subjects generally called scientific. For example,
the scientific method can help a person to determine why the
oil light comes on in an automobile (see figure on page 356):
• Hypothesis 1: The car needs more oil. To test the hypothesis:
check the oil level. If this hypothesis is not confirmed,
try another hypothesis.
• Hypothesis 2: The oil has no pressure (the pump is defective).
To test this hypothesis: check the oil pump. If this
hypothesis is not confirmed, try another.
• Hypothesis 3: The oil light is illuminating improperly. To
test this hypothesis, check the oil light itself.
Yet other hypotheses can be suggested: a clogged oil pipe,
for example. This example demonstrates that the scientific
approach can be used in daily life for almost anything (except
miracles).
Where do hypotheses come from? This is the part of
the scientific process that is closest to being an art. Hypotheses
are generated by the minds of scientists who are very,
very familiar with the systems they are studying. In the previous
example, the more one knows about cars, the more