Sylvia Edwards wrote,
"I really don't want to start an argument about evolution ..."
Let's not, and say we did. ;-)
Sylvia, please don't worry about nature being cruel. Nature is not cruel,
though it is also pitiless. People are cruel, sometimes.
<sigh> If we're going to talk about evolution, we may as well get the facts
straight first. I had to look it up years ago before debating Duane Gish,
author of "Evolution: The Fossils Say NO". I will never dignify his views
by doing that again. One of the high points, for me, happened when Dr. Gish
displayed a doctored drawing of Archaeopteryx, the bird-reptile link, from
which the reptilian features had been removed. Of course, he claimed that
it was just another bird, not an evolutionary link at all. Ron McDowell,
then a grad student, shouted from the back of the audience, "What about the
TEETH?" What, indeed.
The basics of the theory of evolution can be stated in a few words:
1. All plant and animal species are, at least in principle, capable of
increasing their numbers beyond the ability of the environment to sustain
the population. Therefore, some young (and old) individuals die without
reproducing first.
2. All species show some genetic variation among individuals, and new
variations show up occasionally.
3. Therefore, given enough time and generations (and freedom from events
that are so stressful that they wipe out the species, e.g., an asteroid
impact), species will tend to change to become better suited to their
environment--more "fit", if you will.
In the 1850's, Darwin didn't know about Mendelian genetics, mutations in
DNA, or asteroid impacts, so I've had to update his statements a bit. A lot
has happened in the last 150 years.
The concept of "fitness" turns out to be difficult to pin down, and deep
thinkers have pointed out that the concept has to be phrased very carefully
(more carefully than I have done) if the statements are not to fall into
circular reasoning. "The survivors survived, so they must have been more
fit"--What can the word "fit" mean, if every individual of every species
currently living on the planet is descended from an unbroken chain of
successful ancestors? It's easy to be glib, not so easy to be logical. In
fact, some species seem to evolve into dead ends. Their forms and behavior
are so specialized that even a tiny change in the environment can wipe them
out. Every generation succeeded in reproducing, and they changed along with
their environment, but they did not necessarily become more "fit" to meet
every new circumstance.
Example: Think of the dodo, big as a turkey, fat and sassy on the island of
Mauritius, the largest land animal there, afraid of nothing. Wingless.
Stupid. (They may have looked like pigeons when they first arrived on the
island. For generations, birds without wings reproduced better than birds
with wings. Wings take up a lot of body weight and energy; why have them if
you don't use them? Lots of island birds are wingless. The same goes for
extra brain mass.) Enter European sailors, who leave dogs, rats, and pigs
on the island after gleefully clubbing a lot of birds for food. The sailors
didn't kill them all. But the dodos nested on the ground, and they couldn't
keep the new, non-native animals from eating their eggs and young. End of
reproduction, and soon, end of dodo, as surely as if an asteroid hit. A few
survived on an offshore islet for a while before succumbing. Not a pleasant
story, but more unfortunate than cruel, with the notable exception of the
sailors, whose cheerful attitude toward killing is a matter of record.
Anyway, the dodo was certainly well suited to its environment for many
generations, but failed to adjust to a drastic change around it. So what
does "fit" mean when applied to the dodo? The answer depends on when you
look: before or after the sailors arrived.
Obligatory shell example of evolutionary "fitness": The common edible
garden snails of California mate by spearing each other in the foot with
darts and then reeling each other in for a bout of hermaphroditic sex. This
would be grossly immoral behavior for humans, but it works for the snails,
which end up having twice the number of eggs that would otherwise be laid.
Any gardener in California can attest to how effectively the little pests
reproduce. Since the behavior, however cruel and bizarre, does contribute
magnificently to the perpetuation of this species, there is no reason for
the snails to change. A biologist would say that there is no "selective
pressure" to change this behavior, but I've been trying to avoid the
jargon.
Does evolution act to better the world? This is not a trivial question, but
the theory of evolution is not very helpful in answering it. The theory of
evolution is ethically neutral; it does not say anything about the
survivors who reproduce being morally superior to those who die without
reproducing. Dodos who died under new circumstances beyond their control
were not morally inferior to their dodo ancestors. The theory is morally
neutral even when applied to the human species, though people like the
Nazis have certainly tried to say that one group or another is more "fit"
and therefore deserves more land and property. This is called "social
Darwinism", though Darwin did not originate it and he would probably have
been as dismayed by the idea as St. Paul would by the holy wars of
Catholics and Protestants.
Most of the larger Christian denominations in the United States regard
evolution and the "billions and billions of years" idea as compatible with
faith, including Roman Catholic, Greek Orthodox, Episcopalian, at least one
Methodist sect, two of the three Lutheran sects, and one of the two
Presbyterian sects. I'm not sure about the Latter-Day Saints, Disciples of
Christ, and Southern Baptists, but I do know devout individuals of these
sects who see no contradiction. But evolution is a problem for sects that
believe in the literal reading of the Bible, rather than allegorical
interpretation, because the Book of Genesis states that the world was
created in six days. It's also a problem for people who are offended by the
idea that they may be better than their remote ancestors were. Oddly
enough, the same idea gives me hope for humanity's future.
Andrew K. Rindsberg
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