18 Evolution and the Fossil Record
culture and attempts to make outrageous ideas more believable. For example, when the cre-
ationists realized that they could not pass off their religious beliefs in public school science
classrooms as science, they began calling themselves “creation-scientists” and eliminating
the overt references to God in their public school textbooks (but the religious motivation
and source of the ideas is still transparently obvious). Several churches (including Christian
Science and Scientology) appropriate the aura of scientific authority by using the word “sci-
ence” in their names, even though they are not falsifiable and do not fit the criteria of science
as discussed here. Similarly, the snake oils and nostrums peddled by the telemarketers and
by the “New Age” alternative medicine fanatics are often described in what appears to be
scientific lingo, but when you examine it closely, they are not actually following scientific
protocols or the scientific method. The are the famous examples of television commercials
that show an actor in a white lab coat, often with a stethoscope around his neck, saying, “I’m
not a doctor, but I play one on TV” and then promoting a product that he has no medical
training to analyze. However, just the appearance of scientific and medical authority is suf-
ficient to sway people to buy his product.
- Correlation Is Not Causation
Human beings are programmed by our genes to see patterns in nature and to recognize con-
nections between things. Yet sometimes these instincts lead us astray. We wear a particular
item of clothing one day, and our team wins; we forget to do it once, and they lose. Then we
are convinced that wearing that item is “lucky” for the team, and we wear it every time, no
matter whether the team wins or loses. We cannot shake this superstition, and no amount of
falsification from future failed predictions will change it. Many people believe in “earthquake
weather,” because they recall one or two very strong earthquakes that happened to occur
on hot mornings. They are not dissuaded when you point out that the daily temperature
fluctuation due to weather is not felt more than a few feet underground, while earthquakes
come from faults that are many miles underground. One or two coincidences are enough to
reinforce this “urban myth.” Seismologists have done rigorous statistical analysis again and
again and have shown conclusively that earthquakes of all sizes occur in any weather and
at any time of day or night. The most common form of this superstition is known as the post
hoc, ergo propter hoc (“after this, therefore because of this”) fallacy.
Scientists are also prone to believe that there is some connection when they see one or
two positive results in a row. But as scientists, we are trained early in our careers to study
the mathematics of probability and statistics, so that we can analyze in a rigorous way
whether an apparent connection between events is truly significant or still could be due to
chance. Although scientists still use hunches and intuition to guess that phenomena might
be related, once they try to publish their ideas in a peer-reviewed journal, they had better do
the appropriate statistics, or their article will be quickly rejected!
A good example of this was the furor caused in the 1980s, when paleontologists David
Raup and Jack Sepkoski (1984, 1986) made the claim that there were mass extinction events
every 26 million years and that some of them were caused by impacts of asteroids from
space. Astronomers quickly jumped on the bandwagon even before the data were published,
with “explanations” for this extinction “periodicity” that ranged from a mysterious Planet
X to an undetected companion star to the sun called “Nemesis” to the motions of the solar
system within the galactic plane to periodic pulses of mantle overturn triggering global vol-
canism. But, as the original data were scrutinized more closely, the correlation began to fall