This is because natural selection acts to increase the prevalence of highly advantageous alleles, over time generating common resistance alleles of especially strong effect. For example ...

Charles Darwin and the Theory of Natural Selection. By Edward B. Poulton, &c, Hope Professor of Zoology at the University of Oxford. Pp. 224. (London, Paris, and Melbourne: Cassell and Company ...

The phrase "survival of the fittest" functions principally in evolutionary theory to describe the biological concept of ...