You come across something like that, and you go, huh? Should I significantly lower my expectations for this allegedly landmark popular science book? But then I remembered it was written in the 1976, when not that many people had an idea what a computer was, so such an explanation might have been appropriate back then.
So this book, as one might guess, is easily accessible to a non-scientist. And yet it does not dumb things down. Quite the opposite. Perhaps it's a fortunate choice of subject matter, but this book, like few others, can lead a reader to uncover philosophical implications that go beyond the subject matter.
The eternal game of cheaters versus cooperators
The further I read, the more amazed I was at the incredibly complex, sophisticated games that genes play to propagate themselves. As we all know, a gene will become more common in the genome if it enables a body it inhabits to make more descendants. Occasionally a gene predisposes an individual towards cooperative behavior. A bunch of cooperating individuals (for example, hunters hunting a big prey), are more likely to eat better, live longer and reproduce more. So the gene for cooperative behavior gets replicated more, and becomes more frequent in the population. However, cooperation requires each individual to invest something -- time, energy, muscle power. Investing it means depleting their resources, and possibly putting themselves at risk, so they'll reproduce less than they would if they didn't have to expend those resources. If you could get the goods for free while letting your teammates do all the work, you'd be likely to reproduce more. If by an accidental mutation you acquired a gene that allowed you to trick your teammates into thinking you are cooperating while you are really not -- then you would get to reproduce more at their expense, and your "cheat" gene would become more common in the population.
That's a simple concept. What's fascinating is how complex are evolutionary strategies that arise from this simple premise. I won't go into examples now, because the book is so full of fascinating examples it's hard to pick just one. From the loudness of baby birds' cries, to the reason why there are two sexes instead of just one, and why an egg is so much larger than a sperm -- the theory of cheating versus cooperation can explain all that.
According to Dawkins, the extent of cooperation versus the extent of cheating can be predicted by a degree of genetic relatedness between individuals in a population. The amount of genetic material the individuals have in common can be quantified mathematically; based on game theory one can then predict the ratio of cheaters to cooperators. Dawkins manipulates numbers, but he manages to illustrate his point without a single equation. A reader does not need to know more than addition, multiplication and subtraction of fractions to understand his math.
From a simple premise, an intelligent-like behavior
But it wasn't so much the math that made this book fascinating, as all the diverse, sophisticated strategies the genes engage in to propagate. Sometimes you can't help but get a feeling that the "behavior" of the genes is driven by nothing more than keen intelligence. And yet there is no "behavior" and no "strategy" in the real sense; genes, of course, have no minds and can't consciously come up with strategies to reproduce; what appears to be a behavior is merely a consequence of a very simple fact: a gene that encodes a trait or behavior that helps a body to make more descendants will become more populous. To see how intelligent-like behavior of enormous sophistication emerges from this simple logic was to me the most fascinating aspect of the book. While "emergent behavior" has been a popular buzzword for the last few years (or maybe it came on my radar only recently), I haven't read a popular science work that illustrated this concept so well -- and this book was written 3 decades ago! (Admittedly, I haven't read "The New Kind of Science". But it's been on a lot of smart people's quack radar, so I'm not sure I should invest time in it.) Thus, the philosophical impact of "The Selfish Gene" transcends its subject area.