The selfish gene

Dawkins thesis is that we are survival vehicles built by our genes.

He describes how life could have started beginning with a primeval soup of simple chemicals. The first step is that stable molecules would build up over time. Then one molecule, called a replicator, would 'discover' how to make copies of itself using other molecules. Evolution came about because the replicator's copying process was not perfect and sometimes mistakes would be be made. Most of the mistakes were detrimental, but every once in a while they were advantageous. In this manner new kinds of replicators evolved. Some replicators formed groups with others, which gave them both advantages over the other lone replicators. Eventually these molecular replicators added barriers to protect themselves from the outside environment. They had built what we know as living cells, and multi-cellular bodies. This is what Dawkins calls survival vehicles. The replicators, or as they are more usually called genes, have built us as their survival vehicles.

Some of my favorite quotes
Let us try to teach generosity and altruism, because we are born selfish. Let us understand what our own selfish genes are up to, because we may then at least have the chance to upset their designs, something that no other species has ever aspired to.
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I shall argue that the fundamental unit of selection, and therefore of self-interest, is not the species, nor the group, nor eve, strictly, the individual. It is the gene, the unit of heredity.
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The precise thornbush shape of a protein molecule such as haemoglobin is stable in the sense that two chains consisting of the same sequences of amino acids will tend, like two springs, to come to rest in exactly the same three-dimensional coiled pattern. Haemoglobin thornbushes are springing into their 'preferred' shape in your body at a rate of about four hundred million million per second, and others are being destroyed at the same rate.
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The earliest form of natural selection was simply a selection of stable forms and a rejection of unstable ones. There is no mystery about this. It had to happen by definition.

Can we reconcile the idea that copying errors are an essential prerequisite for evolution to occur, with the statement that natural selection favours high copying-fidelity? The answer is that although evolution may seem, in some vague sense, a ' good thing', especially since we are the product of it, nothing actually 'wants ' to evolve. Evolution is something that happens, willy-nilly, in spite of all the efforts of the replicators (and nowadays of the genes) to prevent it happening.

They have come a long way those replicators. Now they go by the name of genes and we are their survival machines.

There is no gene which single-handedly builds a leg, long or short. Building a leg is a multi-gene cooperative enterprise. Influences from the external environment are also indispensable: after all, legs are actually made from food! But there may well be a single gene which, other things being equal, tends to make legs longer than they would have been under the influence of the gene's allele.