Ask A Scientist© Biology Archive

Question:  Why are biology books written as if everyone believes in evolution?
I am a creationist, and I am offended by the way the text is written.
I haven't taken biology for three years because the last text I read
made fun of creationists as people who believe in the "pseudo-science."
Judi Y Wu

Answer 1:  Biology is a science, and, as such, is based on the scientific
method. As long as creationism is based on faith and religion,
I see nothing wrong with it: why couldn't God have created an
evolving universe? Saying that creationism is science merely
demonstrates an ignorance of the definition of science.
Please try to understand what the scientific method *means*!
Jade Hawk 

Answer 2:  
We might distinguish between "evolution," meaning the process by which 
environmental pressure produces fitter species, and "Evolution," the process 
we think produced human beings starting from amoebas, more or less.
The first is not a subject of rational debate: it is an observable fact.
If you stomp on reproducing species in a certain way, then they will
gradually become more resistant to that kind of stomping --- they will
adapt to their environment.  The existence of new, drug-resistant strains
of tuberculosis or the fact that HIV kills people only after a number of
years are both direct observations over a short time (decades) of evolution
in bacteria and viruses.  There are many other cases cited in the usual
evolution literature, e.g. the moths in England that became dark to hide
against soot-blackened trees at the beginning of the Industrial Revolution.
   But let's not confuse evolution with Evolution.  Even if we grant that
bacteria or moths can evolve over a period of decades or centuries, simply
because we can watch them do it, how can we imagine *people* evolving from
*bacteria*, even over a much longer period?  Understandably this is a lot
harder to swallow.  There have been many objections raised to this
proposal, and the best of them are quite insightful and cannot be dismissed
with a laugh.  For example: in the nineteenth century, when Evolution was
first proposed, the age of the Earth as estimated by the geologists was
only a few millions of years, and even the most ardent Evolution supporters
did not consider this enough time for Evolution to have done its work.
Today we know from radioisotope dating that the Earth is a lot older and
time enough for Evolution has indeed passed.  Number 2: the fossil record
is far from complete.  You've heard of the Missing Link between people and
apes?  There are many missing links, many places where the chain of
Evolution is presumed to link preceding to following species, but where
there is no fossil evidence.  The worst part is that there is almost no
evidence at all of life from its beginnings until the first bony creatures
existed (a mere 600 million years ago or so).  That's an enormous gap,
between bacteria and crabs, and certainly one of the most hard-to-buy parts
of Evolution.  The Burgess Shale and like soft-body fossil finds have been
a tremendous recent help here, but there are still events in Evolution
which are of critical importance but for which we have no hard evidence of
their occurrence, e.g. the transition to DNA as the sole genetic material
for all life on Earth.  Number 3: even if we accept that life can evolve
from life, how do we know it can evolve from non-life?  We've never seen it
happen, nor is there any clear record of it having happened.  People have
nevertheless made strong arguments: it's been proved, for example, that
amino acids are made naturally by lightning in volcanic gases.  It's been
shown that RNA can catalyze reactions on itself, so that the
"chicken-and-the-egg" problem with genetic material and the cell (the
genetic material codes for the cell, but the cell makes the genetic
material, so which evolved first?) has been resolved.  Number 4: evolution
(small e) proceeds by adapting existing characteristics.  If you can't show
how a complex body part evolved step by step from some simpler body part
such that *at each step* there was an advantage over the earlier form, then
evolution cannot have produced the change.  Example: how did wings evolve?
You can't imagine a species sprouting little stubs that slowly got longer
with time until it could fly.  There'd be no advantage to the stubs, and so
they would not persist for generations.  And at the same time the species
can't suddenly sprout fully-designed and adapted wings out of nothing.
This is a very challenging objection.
Christopher Grayce