Some have said of On the Origin of Species that it is all about pigeons.
Charles Darwin was fascinated by them. To help develop his thinking, he kept many different varieties and joined two local pigeon clubs to meet breeders. From one ancestral species, the rock-pigeon, hundreds of domestic breeds have been brought into existence. Darwin referred to the process as artificial selection: birds with desired characters are selected by the breeder for mating. Offspring with the strongest presence of desired characters are again selected for further breeding. By repeating the process, remarkable traits can be isolated, leading to characteristics that are novel and distinctive. Darwin wrote: ‘The diversity of the breeds is something astonishing’. However, his understanding of this diversity was seriously mistaken.
Breeder and environment
Crucial to Darwin’s thinking is that the ‘breed’ is just part of a continuum of variation. Beyond these are new species, new genera, new families, and so on. Apart from timescales, artificial selection was considered to be essentially the same as processes operating in the natural world. He wrote in his chapter on natural selection: ‘As man can produce and certainly has produced a great result by his methodical and unconscious means of selection, what may not nature effect?’ Instead of the breeder, we have the changing environment. Instead of intelligent and purposeful selection, we have unintelligent and unplanned processes that bring gradual changes to breeding populations of animals and plants.
