• Choose a category
• All
• Classic-Fiction

By Root 623 0

but for a few exceptions, a couple of adaptations produced by non-Darwinian processes at work in biology. That leaves too much wiggle room for compromises with theism. The official Roman Catholic view, for example, revels in this wiggle room. Their religion is much more erudite than crude Protestant Fundamentalism (think how much Roman Catholicism owes to Aristotle and Augustine). The Pope allows that Darwin got it right from the beginning of organic life 3.5 billion years ago right up to the primates. The only exceptions are humans, who have been given souls one by one through divine spark for about 250,000 years now. If Darwinian biology allows a few exceptions, it won’t be able to keep the floodgates closed against intelligent design, special creation, or even biblical inerrancy.

To close down the wiggle room, Darwinism (and, of course, scientism) needs to show that the only way adaptations can ever happen—even the most trivial and earliest of adaptation—is by natural selection working on zero adaptation. We must demonstrate that given the constraints of physics, adaptation can have no source other than natural selection. To do this, first we’ll show that natural selection doesn’t need any prior adaptation at all to get started; beginning with zero adaptations, it can produce all the rest by physical processes alone. The previous chapter gave us the two core ideas we need for this task: the causal completeness of physics and the second law of thermodynamics. The rest of this chapter shows how the physical facts can produce all the adaptation Darwinism needs from a zero-adaptation starting point.

With these two starting points—the second law and the completeness of physics—we can do more. We can close down the wiggle room. We can also show that the process Darwin discovered is necessarily the only way adaptations can emerge, persist, and be enhanced in a world where the physical facts fix all the facts. That is the task for the next chapter.

THE PASSIVE FILTER AND THE SLIGHTLY ERRATIC COOKIE CUTTER

To show how the process of natural selection follows directly from physics, we first need to state Darwin’s discovery properly. One neat, simple, and very general description of the process was originally advanced in the 1970s by the well-known biologist Richard Lewontin. It’s not perfect, but adding further details wouldn’t affect the derivation of all Darwinian processes from physics.

According to Lewontin’s version, adaptative evolution occurs when there are heritable variations in fitness. Lewontin identifies three conditions, each of which is necessary and when taken together are sufficient for the evolution of adaptations:

1. There is always variation in the traits of organisms, genes, hives, groups, or whatever it is that replicates or reproduces.

2. The variant traits differ in fitness.

3. The fitness differences among some of the traits are inherited.

The process that exploits these three conditions is natural selection. This is not the whole of Darwin’s theory or its later modification by a century of discoveries that refine it in many ways. But it is the essence of how the means/ends economy of nature emerges, without purpose ever intervening. The process takes the variant traits in each generation and filters them for fitness differences. It allows those attaining a minimum level of fitness to survive at least long enough to be replicated in the next generation.

The replication isn’t always perfect. Once in every hundred copies, or every thousand, or every million, something goes slightly or badly “wrong” in the copying process. It’s as though you had an animal cracker cookie cutter that changed shape slightly (sometimes even not so slightly) and unpredictably once in every 10 or 20 or 100 cookies it cut. Every so often, out comes a cookie different from all the rest. Sometimes it’s better—less burned because it’s thicker, less likely to break because it has fewer sharp edges, showing more clearly the shape of the animal the cookie is supposed to look like. But most of these unpredictable, uncontrollable