Dawkins, Richard. Climbing Mount Improbable. New York: W. W. Norton & Company, 1996.

One stage in the Darwinian process is indeed a chance process – mutation. Mutation is the process by which fresh genetic variation is offered up for selection and it is usually described as random. (p. 80)

Natural selection, the second stage in the Darwinian process, is a non-random force, pushing towards improvement. Mutation, the first stage in the process, is random in the sense of not pushing towards improvement. All improvement is therefore, in the first place, lucky, which is why people mistakenly think of Darwinism as a theory of chance. But mistaken they are. (pp. 85-86)

We have identified the ingredients that must be present before evolution can occur as being mutation and natural selection. These two will follow automatically on any planet given a more fundamental ingredient, one that I difficult, but obviously not impossible, to procure. This difficult basic ingredient is heredity. In order for natural selection to occur, anywhere in the universe, there must be lineages of things that resemble their immediate ancestors more than they resemble members of the population at large. Heredity is not the same thing as reproduction. You can have reproduction without heredity: Bush fires reproduce without heredity. (p. 88)

To repeat because it is so important, the DNA that has made it down the river of time is DNA that has, for hundreds of millions of years, inhabited the bodies of successful ancestors. Lots of would-be ancestors have died young, or failed to find a mate. But none of their DNA is still with us in the world. (p. 90)

Mutations of large effects like this – ‘macro-mutations’ – are sometimes called saltations. (p. 97)

however many ways there are of being alive, it is certain that there are vastly more ways of being dead. (p. 99)

The reason for this wantonly confusing piece of terminological contrariness is actually quite simple, and even rather interesting. We recognize what a gene does by noticing what happens when it goes wrong. (p. 190)

Now, it is a general fact that although all of an animal’s genes are present in all its cells, only a minority of those genes are actually turned on or ‘expressed’ in any given part of the body. This is why livers are different from kidneys, even though both contain the same complete set of genes. (pp. 191-192)

Natural selection is the pressure that drives evolution up the slopes of Mount Improbable. Pressure really is a rather good metaphor. We speak of ‘selection pressure’, and you can almost feel it pushing a species to evolving, shoving it up the gradients of the mountain. (p. 198)

Flowers and elephants are ‘for’ the same thing as everything else in the living kingdoms, for spreading Duplicate Me programs written in DNA language. (p. 272)

Once the first spontaneous replicators existed, evolution could proceed apace. It is in the nature of a replicator that it generates a population of copes of itself, and that means a population of entities that also undergo duplication. Hence the population will tend to grow exponentially until checked by competition for resources or raw materials. (p. 285)