There are only two known sources of knowledge creation: Biological Evolution and the thoughts of People. They have some key differences. In the case of human knowledge, the variation is by Conjecture, and the selection is by Criticism and experiment. In the biosphere, the variation consists of mutations (random changes) in genes, and natural selection favors the variants that most improve the ability of their organisms to reproduce, thus causing those variant genes to spread through the population.
The central idea of neo-Darwinism is that evolution favors the genes that spread best through the population. A common misconception about Darwinian Evolution is that it maximizes ‘the good of the species’. In reality evolution promotes the propagation of individual genes (sometimes to the detriment of the species).