This means that the unit can expect to survive for a large number of generations in the individual’s descendants. A single cistron is likely to be much less than 1 per cent of the length of a chromosome. Even a group of several neighbouring cistrons can expect to live many generations before being broken up by crossing over. (Location 592)
We, the individual survival machines in the world, can expect to live a few more decades. But the genes in the world have an expectation of life that must be measured not in decades but in thousands and millions of years. (Location 681)
We have already asked what are the most general attributes of a ‘good’ gene, and we decided that ‘selfishness’ was one of them. But another general quality that successful genes will have is a tendency to postpone the death of their survival machines at least until after reproduction. No doubt some of your cousins and great-uncles died in childhood, but not a single one of your ancestors did. Ancestors just don’t die young! (Location 790)