I have often heard and have at times gotten into arguments about whether the process of evolution has directionality. And this argument has seen lots of air time in the media recently. I realized the other day that there is a fictional dialog that lives in my head about this topic that misleads me about the actual source of disagreement.
If you picture the argument in your own mind's eye you are likely to see that on one side there is a strong-Darwinian materialist claiming that the universe is like a blind clockmaker who stumbled upon this world through a process driven by nothing but chance. On the other side is a romantic fundamentalist claiming that monkeys cannot write Shakespeare and therefore there must be some intelligence guiding the evolutionary process.
What I realized was that no one actually denies (as far as I can tell) that there is an apparent directionality behind the universe's unfolding. Evolution clearly happens in a particular direction. For instance you can't imagine animals evolving on a barren planet before any plants appeared. Plants needed to come first – that is directionality.
What people do argue about is the mechanism of directionality. Darwin‘s hugely significant discovery was a theory that satisfactorily explained the apparent directionality of the evolution of species. That theory he called “Natural Selection by Chance Variation.” Essentially it states that the individuals of any given species are born with variations in characteristics. Some of these variations have survival advantages and are passed on genetically to offsprings. Over time successive generations will become more uniformly adapted to the environment. And at times one species transforms into a new one through this same mechanism.
Darwin had this insight and then sat on it for 20 years before publishing his findings in the book, “On the Origin of Species” and only then because another scientist published a paper explaining a dangerously similar theory. One of the reasons that Darwin's theory was and is so controversial is that he explained the evolution of species, which meant the development of man, without needing to appeal to any form of intelligence or God. He could explain man's development through purely mechanical means.
Darwin could see that evolution had directionality and he could explain that directionality through a process resting on chance variation and survival. There are good arguments against Natural Selection being the only mechanism through which evolution occurs and many find it necessary either for logical or sentimental reasons to theorize that some form of intelligence must be behind the process. But they are not arguing for or against directionality – they are arguing for or against telos.
Telos is a Greek word meaning purpose. And this is where the problems start. Darwin found a mechanism for evolution that was devoid of purpose. If there is no intelligence behind evolution then there is no ultimate purpose, no final destination or goal that we and the universe are heading for. This leaves many of us with an uneasy feeling because it goes against our deeply felt conviction that there is a purpose to life, that there is meaning to existence. So this is the actual point that the argument pivots on, not if there is directionality to evolution – for surely there is that – but if there is purpose. OK, let the argument continue.