1. Charles Darwin. The Origin of Species. John Murray, 1859. The world-famous book introducing the theory of evolution, based on Darwin’s observations from his trip in the Beagle.
2. R. Dawkins. The Selfish Gene. Oxford University Press, 1976. A “pop-science” classic, promoting “neo-Darwinism” as a synthesis of evolution with modern genetics. Its very “gene-centric” view of evolution, has been questioned by some.
3. J. Maynard-Smith. The Evolution of Sex. Cambridge University Press, 1978. A good, readable introduction to the biological basics of reproduction in haploid and diploid organisms.
4. S. Wright. The roles of mutation, inbreeding, cross-breeding, and selection in evolution. In: Proc. of 6th Int. Congr. on Genetics, vol. 1, pp. 356–366. Ithaca, NY, 1932. The paper introducing the idea of the adaptive landscapes.
5. D.B. Fogel, ed. Evolutionary Computation: the Fossil Record. IEEE Press, 1998. Fascinating collection of early works in the field, interesting not just for historical insight.