Donnerstag, 16. Juni 2011

Is evolution guided?

If life originates and makes progress, then clearly something inherent in itself must be organising it. Is there any reason to believe that once life arose on earth, it was subsequently "organised" to progress along a given course which has led to emergent complexity and ultimately us? For an answer to such a question — one which pertains to life and living things — we have to turn to biology and, thence, to its most fundamental and successful formulation to date — the theory of evolution. Unfortunately, that doesn't get us much beyond a resounding "no".
That's because the forces that impel evolutionary processes are blind. They have no foresight that says: if this is done then that will happen. It's a continuing process of trial and error where if by chance a random mutation succeeds in benefitting the organism, it tends to get retained and repeated through later generations until conditions change and other chance mutations are incorporated. Those organisms that accidentally get dealt a better biological deal become better adapted to their environment. Those that don't, can't compete and die out.
When Charles Darwin and Alfred Russel Wallace first formally presented their account of how nature works, it ran headlong into ages of received religious wisdom — initially for the wrong reasons and later for what religion considers is the right reason now. Meaning, in the beginning, people were simply aghast at the sudden notion that monkeys and humans could have a common ancestor. After all, weren't we made in His image? Today, however, they reject evolution on more refined theological grounds — namely, that it's purposeless, whereas the entire majesty of their faith stems from the belief that creatures like us are the end product of a design.
And there the argument could have teetered forever if it wasn't for one niggling trend that has made itself manifest throughout the history of life on this planet: the progression towards an increase in order and complexity. From the time the first tiny unicellular organism got its RNA up and running to all life today, life has only got more organised, denser, intricate and complicated than what came before. Since evolution is the only thing that's totally responsible for this progress, how accidental could it be? How blind is that?
Some mechanistic evolutionary biologists who see in this an implicit threat to the blind-and-accidental paradigm deny any progression involved at all by denying it outright. Lynn Margulis in What is Life? flatly states: "All species are equally evolved"; Stephen Jay Gould says: "There is no progress in evolution"; and Richard Dawkins of The God Delusion fame clocks in predictably with "We all agree that there's no progress".
However, this ignores the plain facts of life and evolution and, luckily, some scientists have not been so blind themselves. Edward O Wilson, the American biologist, researcher and author writes in The Diversity of Life: "Progress is a property of the evolution of life as a whole by almost any conceivable intuitive standard. . . . Let us not pretend to deny in our philosophy what we know in our hearts to be true."
Perhaps the geneticist Theodosius Dobzhansky sums it up best when he observes that evolution as a whole doubtless had a general direction, from simple to complex, from dependence on to relative independence of the environment, to greater and greater autonomy of individuals, greater and greater development of sense organs and nervous systems conveying and processing information about the state of the organism's surroundings and, finally, greater and greater consciousness.
From simple cellular life, tissues and organs to the diversity of plants and animals, families, communities and global ecosystems, life is progress at every scale. If anything, the evolution of life is the increase of biological organisation. If life originates and makes evolutionary progress — without complexity and organising inputs from outside — then clearly something inherent in itself must be organising it.

Mukul Sharma, Is evolution guided?, 16.6.11, The Times of India

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