A Short History of Evolution: In The Beginning

This article is part of Carl Coon’s ongoing “A Short History of Evolution” series. Click here to read Part 1.

Entropy and Evolution

Let’s begin with cosmology. Cosmologists tell us the universe began almost 14 billion years ago in a huge burst of energy, the Big Bang, and everything has been unfolding ever since, following the general principle of entropy. After the Big Bang everything runs down and energy dissipates until finally, a few billion years from now, the whole grand show that started with a bang ends with a kind of whimper. It’s not a feel-good kind of scenario, but it does give us a lot of time, and it lays the basis for some important principles.¹

The idea of entropy has the kind of explanatory power we need to get back to first causes. It’s one of the principles, like gravity, that is literally universal. You don’t mess around with such concepts, but take them as given, solid anchors for whatever theoretical structures you want to erect over them.

But specifically, how do we define entropy? This poses a problem: all through this narrative I have had to consider how to define terms that annoy specialists when the public uses them in ways it understands, but are incomprehensible to the public when the specialists use them in ways they consider correct. Entropy is such a word. It has a specific use in thermodynamics and if you are a physicist that’s fine, but I am not writing this just for physicists. For this study, entropy is diffusion of energy, a running down, a wearing out, and decay. It is what happens to a living thing after death.

Is there an opposing force that exists as the equal and opposite of entropy? If not, how do you explain life? I find it useful to use the word “evolution” in its broadest sense to provide a name for that opposing force. This implies that evolution isn’t just something that emerged when life began; it was instrumental in creating life in the first place. If there is life on other planets, that life should be as subject to the basic laws of evolution as rocks on that planet are subject to the law of gravity.

If we can assume that evolution exists as a universal force that functions as the opposite of entropy, it follows that evolution creates complexity out of simplicity, and concentrates energy. These principles, complexity and power, appear in many guises in our narrative, but I hope to demonstrate that they provide an underlying unity for the whole evolutionary process on earth, just as Beethoven’s initial theme unified the Eroica variations.

The test of any theory is how well it fits the known facts, and how well it predicts outcomes. One test of this theory will be whether the twin criteria of complexity out of simplicity and concentration of power fit what we know about both biological evolution and the quite different phenomena associated with cultural evolution.

To the extent our theory works, we have a starting point for an analysis of evolution that finds comfortable places for both biological and cultural evolution. This should clarify the longstanding controversies over gene-culture evolution, group selection theories, and sociobiology.

 

Evolution and Progress

Progress is a word that means many things to many people. For present purposes we define it as the direction followed by evolution. It relates to evolution the way decay and disintegration relate to entropy. It follows that progress happens when changes occur that move whatever is changing in the direction of concentration of power or greater complexity, or, usually, both.

On our planet, biological progress happens when entities reproduce in sufficient quantities to allow for a winnowing process, with selection favoring the ones that best fit the environment. Once an entity is created, there is no turning back, it will either prosper or die. If it survives and reproduces (or gets copied), it will become a platform for further evolutionary change, even if its introduction has thrown up new problems (which is likely to be the case).

Cooperation between entities is the engine of progress.² We call it symbiosis when it occurs naturally. Symbiosis can create a new kind of entity better equipped to cope with its environmental requirements. When that happens, the new entity will proliferate. It may even effect significant change in the environment itself.

Some changes can make the whole evolution game, as played in a particular environment, proceed on an altered basis. This transformation can be so gradual as to be imperceptible, or it can occur over a relatively short time span, like a step in a flight of stairs. If the changes follow the latter path, it can be a modest step, or something so radical and abrupt that it shakes up the whole environmental framework. When the change is sufficiently profound, we can construe it as a significant punctuation point in the whole history of evolution itself.³

This “short history” focuses on such punctuation points. It is not a narrative of what happened as much as an analysis of when and how and why the evolutionary process itself changed.

 

The Origin of Life⁴

Before life on our planet began, parts of the environment favored the combination of molecules into increasingly large aggregations. Such aggregations might be helpful enough to the constituent parts so that they would stay together. This conjoined entity eventually might find other congenial entities that would fit, in the same sense, and produce a still larger entity. It was all a manifestation of the basic principles of evolution: complexity arising out of diversity, with the more complex entity possessing greater power than its constituent elements could muster if isolated.

Eventually, some of the more complex aggregations developed the capacity to reproduce themselves. At first, it was a relatively simple matter of surviving and splitting. This produced very little variation, but there was still some. A few of these self-reproducing molecules happened to be better adapted than the competition to surviving, and their kind flourished. Meanwhile, molecular substructures evolved that added to the fitness and survivability of the structure to which they belonged. Eventually, single-celled organisms appeared on the scene and life as we know it took over.

Our telephoto lenses aren’t strong enough for a close look at this period. As far as we can tell, there was no single path for the evolutionary process that produced life as we know it, no single point in either time or space when a critical juncture was reached. The gradient between the reactions we’d consider part of inorganic chemistry and those in what we now call organic chemistry is so flat that the argument as to where to draw the line appears more metaphysical than scientific. We can infer that there were a lot of steps and maybe a game-changing breakthrough or two, not just one big leap from the inorganic to the organic.

But that inference isn’t proof, and many people still find it hard to believe that life could have evolved at all in the absence of some kind of intentional force, which some would call divine intervention. I reject the whole idea of divine intervention on the grounds that it isn’t needed. When you have a long enough time and are dealing with sufficiently huge numbers, that which has a vanishingly small probability of happening at any given time and place can become very likely to happen someplace. When we are examining the period in which life began we are dealing at the molecular and cellular level and looking at eras that are billions of years in duration. There were many specific environments that could have existed during that unimaginably long period that could have presented opportunities for felicitous combinations. Once that odd combination occurred, if conditions favored its survival, its numbers might increase geometrically over generations, quickly changing something that started as a rarity into something quite commonplace.

Given the current pace of scientific discovery, we may well have better answers as to the origin of life in another generation or two. Meanwhile we have enough evidence to give us confidence in our belief that life originated from natural rather than supernatural causes.

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