The living world is not a single array... connected by unbroken series of intergrades.
Theodosius DobzhanskyNatural selection must be replaced by eugenical artificial selection. This idea constitutes the sound core of eugenics, the applied science of human betterment.
Theodosius DobzhanskyEvolution 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.
Theodosius DobzhanskyEvolutionary plasticity can be purchased only at the ruthlessly dear price of continuously sacrificing some individuals to death from unfavourable mutations. Bemoaning this imperfection of nature has, however, no place in a scientific treatment of this subject.
Theodosius Dobzhansky