In Defence of Darwinism
I used to believe that the theory of evolution was almost universally accepted as the most plausible and intellectually satisfying explanation for the complexity and diversity of biological life on our planet. I am talking about evolutionary theory based on natural selection as set forth by Charles Darwin and subsequently developed by many scientifically minded thinkers like Ernst Mayr and Richard Dawkins. But now, having read enough about Darwinism so that I believe, perhaps naively, that I have mastered most of its basic principles, I find that there are scholastic as well as religious schools of thought that question the fundamental premises of Darwinian evolution based on natural selection.
None of these opposing schools of thought make much sense to me. I shall attempt to refute them here. Probably the weakest part of my argument will be that I have inadequately or even inaccurately described these counter-beliefs. Let this essay therefore be considered the beginning of a debate, not the last word. I shall be happy to stand corrected to the extent I have missed or short-changed the arguments of Darwin's critics, and explore the issues further.
Creationism:
Let's start with the opposing school of thought that is most easily demolished. The fundamentalist, Bible-quoting creationists, as far as I am concerned, are a voice in the wilderness, opposing "Darwinism" not on intellectual grounds, but only because of nostalgia for a bygone era when everyone believed the cosmos could be explained by literal interpretations of the Bible. Serious critics of Darwinism do not, on the whole, explain biological diversity as an Act of God. For those who do, I offer the following very simple, very short argument:
Evolution based on natural selection offers a simple, logically consistent explanation for the emergence of human intelligence without requiring a prior intelligence at least as great as ours to begin the process or guide it. As Dawkins puts it, creationist theories "...assume the existence of the main thing we want to explain, namely organized complexity. The one thing that makes evolution such a neat theory is that it explains how organized complexity can arise out of primeval simplicity."
This essay is directed at stimulating discussion with rational critics of Darwinism based on natural selection. I do not wish to argue with fundamentalist creationists because their arguments are not rational, they are based on faith and faith alone. Challenging that faith usually just gets them mad, and proves nothing.
On the other hand, some of the modern arguments I have seen against Darwinism and natural selection strike me as encapsulating elements of creationist faith cloaked in an imposing hull of modern-sounding verbiage. Where I detect such poison pills in their arguments, I shall say so, and let the fur fly from there.
Evolution and the Second Law of Thermodynamics:
Evolutionary theory based on the principle of natural selection, according to this argument, is unable to deal satisfactorily with the universal tendency toward entropy summed up as the "Second Law of Thermodynamics." Things run down. Evolution works in the opposite direction. Why?
The immediate, common sense answer is that gravity is a universal law too, but we still have airplanes that go up. I don't have to be an aircraft engineer to appreciate the fact that airplanes do actually fly. Similarly, I don't have to explain the exact relationship between evolution and entropy to appreciate the fact that things do evolve in spite of entropy. The existence of entropy in other words is not a valid argument against believing that biological organisms evolve through a process known as natural selection. All the entropy concept does is introduce questions as to how things work. Many of these questions are scientifically valid and lead to interesting conclusions. Many of these conclusions can be discerned in the perceptive analyses of a host of evolutionary scientists like Dawkins and Mayr, and of course Darwin himself. There are still a lot of unanswered questions. Maybe there are still a few unanswered questions in aeronautical engineering. I still fly in planes when I have to.
The Existence of Irreducibly Complex Systems:
How wonderfully complex is the human eye!, the critic exclaims. And what use is half an eye? In other words, these critics question whether highly complex structures like a human eye could ever have evolved gradually, through a whole series of minor modifications, from whatever primitive sensory apparatus belonged to simple one-celled organisms swimming around in the primeval soup.
What these critics fail to appreciate is the incredibly long time span which natural selection has taken to produce present complex organisms. Go back in time a couple of billion years, and put yourself in the position of a primitive living organism in some ancient ocean. You have no capability for seeing, hearing, or smelling. You navigate mainly by touch. The sea around you is swarming with billions of other primitive life forms. Most of them are food, many are siblings and cousins like yourself, and a few are predators. Your purpose in life is to replicate yourself, and to do that you have to consume a fair amount of food without being eaten yourself. You bump around, and if you are lucky you ingest enough food to do your stunt and repeat yourself before a predator happens along.
Now suppose that alone among your siblings and cousins, you discover in yourself a rudimentary sense that allows you to tell where other creatures are even when they are a little distance away, a bit removed from the zone where you apprehend them by touch. You no longer have to bump into them to know they are there. You are going to have a ball, gorging yourself and replicating sooner than any of your peers. Eventually your descendants will have crowded out the descendants of the others that started out like you, but failed to develop that sense of outreach. If it were not for the predators, you would really have it made.
Move down a thousand generations or so. The party is getting rough. All your cousins have the same capability you do and competition for food is as stiff as it ever was. You find that you have, if you work on it, a new and rudimentary capability to sense whether that thing out there in the nearby vicinity is food or a predator. You can tell whether to attack or retreat. Bingo, you are off and running again, and pretty soon the ocean is full of your descendants rather than those of the other members of your peer group.
Repeat this process a thousand times, over a thousand thousand generations, and behold: the eye of the eagle, the ear of the lynx, the echo-location capability of the bat, and the sonar of the whale. There is nothing mysterious about evolution, if you grant a sufficiently generous time span when you look for an explanation of what has evolved. If there is time enough for great leaps to occur in small increments, great leaps can happen.
Evolutionary Theory is Unable to Predict the Future:
Sorry, folks, that's the way it is. Evolutionary theory explains the past based on the assumption that the process is random. Beyond one simple principle: the differential survival of replicating organisms, there is no purpose, no direction, no inherent system or order. All the enormous variety of our planetary flora and fauna can be explained on the basis of individual biological entities getting a jump on the competition through small variations that gave them a competitive advantage in the particular environment they inhabited.
While natural selection does not in itself confer any powers of prediction, it does not prevent attempts to forecast the future based on other information and understanding. We have determined that unless certain steps are taken, the spotted owl will become extinct. In fact, that determination will perhaps have been facilitated by our understanding of how evolution works. Certainly the surviving spotted owls will fare better at the hands of evolutionists than they would if their fate were determined only by the "God put it there, God will decide" types.
Evolutionary Theory Cannot Explain Man's Soul:
Not yet. But a serious scientist should have no problem, even if he is a convinced advocate of evolution through natural selection, in accepting the fact that he doesn't know everything there is to know about our own species, including its perennial preoccupation with matters that are usually called "spiritual". Evolutionary psychologists are finding out more very day about that mysterious archipelago of instinctive, hard-wired responses we know as "human nature". Linguists and others are exploring how we think. The social sciences as a whole are in an exploratory mode, and new insights are rolling in all the time.
The situation is analogous right now to the
knowledge Americans and Europeans had two hundred years ago about
Africa--the "dark continent". We could map its coast
but not its interior, which we peopled with fabulous tribes and
animals and customs, almost all of which proved non-existant as
our knowledge increased.
Surely in another century or so we shall understand the nature
and meaning of humanity's spiritual side more fully and completely
than we do now. And we will be in a better position to determine
how that side of our nature evolved, and what issues that evolution
raises for Darwin's followers, than we are now. Frankly, I believe
the Darwinists will contribute a lot more to that evolution in
our understanding than will those who naysay Darwinism on the
grounds that it doesn't "explain" man's soul.
Conclusion:
There are more arguments and more to be said,
but this is enough for a beginning. Have at me, you critics!
Carl Coon 2/3/98