No evidence is powerful enough to force acceptance of a conclusion that is emotionally distasteful.

Evolution as a process that has always gone on in the history of the earth can only be doubted by those who are ignorant of the evidence or are resistant to evidence, owing to emotional blocks or plain bigotry.

Does the evolutionary doctrine clash with religious faith? It does not. It is a blunder to mistake the Holy Scriptures for elementary textbooks of astronomy, geology, biology, and anthropology.

Nature's stern discipline enjoins mutual help at least as often as warfare. The fittest may also be the gentlest.

The foundations of population genetics were laid chiefly by mathematical deduction from basic premises contained in the works of Mendel and Morgan and their followers. Haldane, Wright, and Fisher are the pioneers of population genetics whose main research equipment was paper and ink rather than microscopes, experimental fields, Drosophila bottles, or mouse cages. Theirs is theoretical biology at its best, and it has provided a guiding light for rigorous quantitative experimentation and observation.

Natural selection must be replaced by eugenical artificial selection. This idea constitutes the sound core of eugenics, the applied science of human betterment.

Seen in retrospect, evolution as a whole doubtless had a general direction, from simple to complex, from dependence on to relative independence of the environment, to greater and greater autonomy of individuals, greater and greater development of sense organs and nervous systems conveying and processing information about the state of the organism's surroundings, and finally greater and greater consciousness. You can call this direction progress or by some other name.