Evolutionary Likelihood

“DNA courses like an ever flowing river down the generations. The river of DNA that flows through us into the future is a pure river that leaves us exactly as it finds us with one exception. There are occasional, very occasional, random changes called mutations. Because of these there is genetic variation in the population and that is what opens the way for natural selection – a world filled with good DNA.”
Growing Up In the Universe, Richard Dawkins

 

I think a lot of us carry a set of unrealistic expectations about how our experiences of body, feelings and mind should be. The idea that others do not suffer the same anxieties we ourselves do is mistaken. Each of us bears our unique habits and preferences, our own hot button issues and our own intolerances yet these all take place against a larger backdrop of what we share in common with everyone else who is having this human experience. Hunger and anger, pride and shame, comfort and anxiety, love and hate all bear a signature that is recognizable however and in whomever they express themselves. Our identification with the characters of theater and movies works because these common, shared human characteristics are so easily recognized.

The question then becomes what attitude will we take towards what we find within the human experience? If you love and care for life as it is, one would do everything in one’s power to nurture and protect whatever life depends on – good food, clean air, and fresh water. Evidently that is not how we feel about this human experience. Evidently, at least collectively, when we see the highs and lows of human nature they frighten and disgust us; we see monsters and animals instead of our humanity.

Contemplative experiences restore the deep mystery of the mind’s awareness to our assessment of human nature. Familiarity with the mind’s vast spaces restores a cosmic dignity to the human adventure. We are children of the stars and do well to remember that, if we are to stay awake to how precious each moment of being alive truly is. I suggest that to appreciate both the fragile nature of the planetary ecosystems on which human life relies and the preciousness of human compassion we need to be thoroughly grounded in evolutionary theory. It provides the modern middle way between the extreme views of an all-powerful creator god on the one hand and blind, meaningless chaos on the other.

Reasoning compliments contemplation. In this instance the reasoning behind evolutionary theory offers a way of understanding where our human nature came from, how it was shaped and formed into what we experience. It is a story of how our very bodies and minds have come forth on a planet teeming with food and challenges. It is your story as you embody yet another expression of the DNA life stream that has run pure for billions and billions of years. The evolutionary perspective can also be used to combat the illusory idea that life should be other than it is. The body, speech and mind that make up the contents of our awareness’ primary experience are not fallen versions of a once perfect, heavenly Adam and Eve but built up gradually, step by step over vast stretches of deep time through a type of exploratory groping through jungles of possibilities – all the ticklishly enticing and equally actual instances of DNA’s expression.

Evolutionary theory takes the steam out of the self-criticisms that arise by expecting ourselves to be something we are not, something other than human. We are working our way towards an understanding of the human mind rooted in evolutionary theory where understanding the forces at work will provide a scientifically solid basis for compassion and empathy. It is easier to have true compassion for oneself and others when the reality of our situation is appreciated. By clearing the deck of ideas such as perfect souls become flawed by sin by being incarnated and human beings purposefully designed deterministically by an all perfect and all knowing designer, we find space is made for nurturing and expressing the value of being a human being on its own terms. The evolutionary perspective also seems critical to me because it removes the narcotic, semi-conscious belief our behavior indicates is widespread; the idea that modern humanity is so special we are bound to succeed. We dare not take it for granted that everything is going to work out fine in the end because some invisible insurance policy is underwriting the human experiment. It is all too easy to allow thoughts of the absolute or ultimate to remove value from the contingent and relative.

That said, none of these comments should be construed as applying to whatever ultimate or absolute may or may not exist. The point is how different views of what reality consists of have implications for how people behave in the here and now. This is more about what is acceptable in public discourse than what one might hold in one’s innermost heart. In public discourse we can expect those involved to appeal only to demonstrably real features of our experience and stick with reasoning for whatever conclusions or explanations of that experience are offered. The likelihood one would rationally assign the hypothesis of a supernatural creator in public discourse changed with the addition of this evolutionary knowledge to our cultural inheritance.

There is no question that evolution by natural selection is a fact of life. Its results are noted in biological laboratories every day. Studying this subject offers an opportunity to exercise intellectual integrity and courage. The reasoning is tight and specifically designed to not depend on any supernatural explanations. Life, which seems so carefully designed for a purpose, is found to not quite be so, not as it seems anyway. These intuitions run counter to much of the philosophical and religious thought within our cultural inheritances. Courage is needed to wield this knowledge as a hammer to tap idols and find which ring hollow but skill is also required if the knowledge is to be effective in conserving what is valuable among our inheritances. This knowledge is a like a sharp sword that while very effective for cutting away ignorance can also cut oneself if we are not careful.

The Reverend William Paley is often credited as representing the traditional view in his 1802 book Natural Theology in which he introduced the world to an (in)famous watch in what has come to be known as the argument by design. The book opens by discussing a man walking along and kicking a rock that then later in his travels coming upon a watch. The rock is a simple object obviously brought forth purely from the interplay of the forces of physics. The watch on the other hand is equally obviously designed for a purpose and whereas the rock could be brought forth by the blind forces of physics, the watch could only have been brought forth by a designer. The good Reverend went on to draw the analogy with the natural world where mountains, clouds, oceans and lands might be brought forth by the blind forces of physics but animals in all their variety and complexity are designed for a purpose and so imply there must be a designer; the Reverend’s creator god.

Hume was the first to point out the argument by design basically shoots itself in the foot. What is to be explained is the order and complexity we find in living things. To propose a designer is just to posit a more ordered and more complex origin since that which could design something as complex as the animal kingdom in all its varieties, including us, must be even more complex in itself. What is posited is no solution to what needs to be explained, it just takes the argument around in a circle.

Daniel Dennett has recently given us a wonderfully picturesque and accurate term for any step in a logical argument that basically just amount to “insert miracle here.” He calls it relying on skyhooks. If building the argument that justifies a large degree of belief in a theory is likened to building a brick building, each part of the logical progression of the argument proceeds by working with what has come before as step by step it progresses to its conclusions. We use cranes capable of lifting the doors and windows of our insights and clarity. A skyhook by contrast attempts to explain a source of design complexity without building on the lower layers. The use of skyhooks is intellectually dishonest.

Though the appeal to a creator fails as a rational argument the very real puzzle remains – animals look “overwhelmingly and compellingly like they were designed.” (Dawkins) Compare the complexity of say a Boa Constrictor to that of Paley’s watch and it is not just more complicated, the Boa is a billion times more complicated. Fred Hoyle, former president of the Royal Astronomical Society, provided a very picturesque illustration of just what it is that needs to be explained. Imagine a hurricane sweeping through a junkyard. The chance of it spontaneously assembling a 747 airplane is equivalent to the chance of an eyeball being formed. Eyes and 747s can’t come into existence by chance, a single lucky shake of the dice, but they can if we spread out the luck. Evolution will then occur if the tiny, lucky steps accumulate. This is key:

Smearing out the luck and accumulating it.

Hoyle’s junkyard hurricane making a 747 drives home the point that chance alone could never produce the complexity of living forms we find on our planet. It is highly improbable, astronomically improbable; in a word it would be a miracle. How then can evolution climb this mountain of improbabilities without relying on a skyhook at any time?

Take the evolution of the eyeball. Eyes have been reinvented in numerous forms by numerous species independently of one another throughout evolutionary history. We can understand how the first step on this design path might be a simple cell that due to a random genetic mutation bears some sensitivity to light. If we imagine this primitive ability to sense light and dark at the base of a huge mountain then the fully formed mammalian eyeball, which is very nearly functionally perfect, would be on the mountain’s peak. On one face of this mountain is a sheer cliff from top to bottom. Jumping from the primitive light sensitive cell to a fully formed eyeball in a single lucky genetic mutation would be like jumping up this cliff. It would need a lucky shake of the dice equivalent to the hurricane producing a 747.

On the other face of the mountain of probabilities, instead of a sheer cliff there is a path winding its way back and forth, leading step by step up to the heights. In places the path might be steep but nowhere is a leap of miracles required. This is Mount Improbable where evolution spreads out the probability. All that is required is that this individual with the light sensitive cell use their limited but potentially useful information to their advantage as it seeks to survive and reproduce. Critics of evolution have asked what good is half an eye. Perhaps the light sensitive cell is just enough to indicate the presence of a predator giving it a slight advantage over its blinder brethren. Over the vast stretches of geological time 1% of an eye is of more advantage than 0%, 1/8 of an eye will prove more adapted than 1/16 of an eye and so on through a gently progression.

It is not enough to have chance find these improbable, but not wildly improbable steps. The results of the lucky break must be retained as per the algorithm: smearing out the luck and accumulating it.

A final illustration well captures the essence of the evolutionary mechanism that allows it to climb Mount Improbable without recourse to skyhooks. This example is demonstrated in the Royal Institution’s Christmas Lecture of 1991 given by Richard Dawkins in part 3, Climbing Mount Improbable. Imagine we have two combination locks. Each has three dials with the numbers one to six etched on them. The first lock is a normal combination lock in that you need to have all three numbers correctly set on the dials for the lock to open. The second lock is different; it uses a gradually opening mechanism so that if you get the first dial correct the lock opens up a little. Set the second dial correctly and it opens yet a bit more and so on.

Because there are three dials with six possible settings each for each lock there are 6 * 6 * 6 = 216 total possible combinations. To open the first lock you have a 1 in 216 chance of guessing right. This is like trying to climb Mount Improbable’s sheer cliff. Opening the second combination lock is a very different affair. To get the first dial to open your luck need only find the one correct number out of six. Do so and the lock will partially open. Additionally, and crucially, once the first dial is correct it remains open so the second dial also only needs a one in six chance to get it right and the same for the last dial. In the gradual combination lock the total number of possible combinations remains 216 but the working out of the correct one explores a space of 6 + 6 + 6 = 18.

Evolutionary action is similar to the gradual combination lock. It smears out luck and accumulates it.

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