Emergence and The Blind Watchmaker

In his 1986 book The Blind Watchmaker, prominent evolutionary biologist Richard Dawkins dismantles the arguments against Darwinism, or the theory of evolution by natural selection.  Although there are various arguments against Darwinism, most are grounded in the belief that nature and natural objects are simply too complicated to be explained by such a seemingly simple process.  Through a number of different arguments and examples, Dawkins demonstrates the power of evolution by natural selection to account for complexity, and argues that no other theory can possibly explain biological complexity.

The title The Blind Watchmaker comes from a famous argument made by William Paley in his book Natural Theology- or Evidences of the Existence and Attributes of the Deity Collected from the Appearance of Nature, published in 1802.  In this classic exposition of the argument for intelligent design, Paley argues that complex objects or organisms necessarily imply the existence of a creator.  He suggests that if one happened upon a watch while walking across a heath, the complexity of the watch could only be explained by supposing an intelligent watchmaker, whereas the appearance of a simple object, such as a stone, would require no such explanation.  Dawkins describes how evolution can explain complexity, and as a passive, undirected process can be thought of as ‘blind watchmaker.’

Anti-Darwinists often indignantly point out that it seems practically impossible for evolution, which they consider a ‘random’ process, to explain a complex organ such as the human eye.  Dawkins explains that only half of evolution is random: random mutations lead to slight variations within a population, which then fade or persist based on their adaptive value.  Selection, however, is fundamentally non-random, and gives evolution the power to generate complexity.  He uses the following metaphor to show how evolution can be conceptualized as a simple ‘sorting’ process, whereby a single rule (selection), applied to generation after generation, can lead to a complex outcome:  Suppose there is a hole in the ground of a certain size and lots of different objects are thrown at it.  This simple procedure quickly sorts a random selection of objects into two distinct groups based on size.  If each of these groups of objects is then passed through another ‘hole’ or filter based on some other parameter, then another, and so on, the initial random input is very quickly sorted into an ordered output through a series of very simple processes.  Evolution works on a similar principle, although it requires only a single type of filter.  Random mutations cause slight variations in a population, and mutations which are adaptive (that is, tend to increase the likelihood of an organism producing viable offspring) survive into the next generation, while others are gradually ‘filtered off.’  Unlike the simplified sorting metaphor, new variations arise in each generation, from which natural selection causes those that are adaptive in the current environment to be passed on and gradually replace less-adaptive characteristics.  Dawkins argues that this simple process of ‘accumulating small non-randomness,’ given enough generations, can capably account for any biological complexity.

Here we find a key idea- given enough generations.  Another sticking point for those who reject Darwinism is that they fail to understand the unimaginably large amount of time that natural selection has been at work.  With millions and perhaps billions of generations through which to accumulate and enhance adaptive traits, it is not too difficult to imagine complexity arising (not so difficult, at least, as being able to truly comprehend numbers of this magnitude).  “But wait,” say the opponents of Darwinism, “aren’t ‘mutations’ new structures or organs that arise complete from nothing, such as an eye suddenly appearing where before there was only bare skin?  Clearly this sort of a mutation seems incredibly unlikely regardless of the number of generations in which it may have arisen.  Surely you don’t expect to explain this away simply by citing lots of generations.”  True, Dawkins, concedes, no amount of time seems capable of explaining such miraculous mutation.  The astounding number of generations, however, means that each mutation need only produce an extremely small change.  Over the millennia, complexity increases incrementally.  It is difficult to imagine an eye arising complete from nothing, but perhaps not so difficult to imagine an eye arising from a mutation to another structure that is already almost-but-not-quite an eye.

This seems reasonably plausible, but the skeptics are not satisfied.  Some consider the suggestion to be that a chance mutation might happen to give an animal a part of an eye, which could serve no adaptive purpose until another random mutation rendered in complete.  These skeptics misunderstand evolution as suggesting that each evolutionary step toward an eye is simply the addition of one component, conferring no advantage until the whole eye is complete.  Instead, each mutation gives the organism something slightly more like full vision, such as slightly better focus, a bit more light sensitivity, or a shade of color distinction.  In other words, each mutation makes for slightly better vision, not necessarily something slightly more like an eye, although the latter tends to follow from the former.  While this answers one argument, some skeptics, continuing with the eye example, find it difficult to believe that an animal with an organ that only gives it five percent vision is better off than an animal with no vision.  Dawkins suggests considering situations in which our own vision may be impaired to a small percent of its full capacity, such as at night or when things are only seen peripherally.  You would clearly be better off trying to avoid a predator on a dark night than in total darkness, or catching sight of an oncoming bus out of the corner of your eye rather than not seeing it at all.  Even a very slight ability to perceive motion could confer a significant adaptive advantage.

In the process of carefully laying out his arguments for evolution, Dawkins repeatedly returns to the idea of evolution as an emergent process.  What is evolution by natural selection, but a simple rule acting in a simple way, and how fantastically complex are the outcomes.   In his own words, “The one thing that makes evolution such a neat theory is that it explains how organized complexity can arise out of primeval simplicity” (316).

Dawkins, R. The Blind Watchmaker, New York: Norton, 1986.