Posted on Tue 16 Mar 2010 under Evolution
As I survey through different blogs and websites and from conversations with certain friends on the topic of evolution, I can almost always encounter an argument that goes something like, "Life could not have evolved through random mutation". This is supposed to be a short and crisp evolutionist stumper. Indeed, how could random mutations produce all the biological complexity in nature?
The answer is in fact the major point, if not the whole point, of Charles Darwin's book, The Origin of Species. He suggested a mechanism that drives the evolution of species to maximum fitness to the environment. Simply put, nature selects the good characteristics or traits from the bad ones in a population of organisms. A portion of the population that that has characteristics that make the species fit for the environment survives and these traits are passed on to the next generation while a fraction of the population that has characteristics or traits that make the species unfit to the environment simply die. This is known as natural selection and is obviously not random at all.
Yes indeed, mutations are random, but this is not the driving force of evolution. It only provides the material for genetic diversity but it is in itself not directed towards any particular purpose. Mutations can be harmful or beneficial. It can even be demonstrated that there are more harmful mutations than beneficial ones. However, natural selection favors the good mutations and perpetuates these more than the bad ones. An accumulation of beneficial mutations can transform a simple organism to a complex one after thousands or millions of generations. Given (1) time, (2) random mutation and (3) non-random natural selection, the seemingly impossible complexity can become possible. With these factors taken together, evolution can never be called random.
There is a huge body of evidence that evolution occurred and that it largely followed the mechanism as described by Darwin, which I don't intend to enumerate and explain in this short article. I personally think, that most people's ideas about evolution describe what evolution is not or some gross misunderstanding of what it really is. Hence, it is important that one really understands what biological evolution means in order to appreciate any pieces of evidence presented.