From The Growth of Evolutionary Science by Douglas J. Futuyma
1. hypothetico-deductive mindset
2. uniformitarianism popularized by Charles Lyell in his Principles of Geology
or the present is the key to the past; an assumption that the natural laws and processes that operate in the present have always operated in the past and are applicable anywhere and everywhere in the universe
coined by William Whewell
3. natural selection
Replacement of one gene by a mutant form of the gene could happen in two ways:
a) The mutation could enable its possessors to survive or reproduce more effectively than the old form; if so, it would increase by natural selection; improved adaptation (Fisher, Haldane, Wright)
b) A new mutation might not be better or worse than the preexisting gene, “neutral”; chance, random genetic drift (Sewall Wright)
neo-Darwinian theory of evolution: evolution is due to mutation and natural selection; random mutations provide abundant genetic variation; natural selection, the antithesis of randomness, sorts out the useful from the deleterious, and transforms the species
5. species: organisms belong to different species if they do not interbreed when the opportunity presents itself; genetically distinct
speciation: An ancestral species splits into two distinct species when different populations of the ancestor, living in different geographic regions, become so genetically different from each other that they will not or cannot interbreed when they have the chance to do so.
Evolution can happen without the formation of new species: a single species can be genetically transformed without splitting into several descendants.
Conversely, new species can be formed without much genetic change.