People are storytelling creatures. We like stories that go somewhere, and therefore we like trends - because trends are things that either get better or get worse, so we can either rejoice or lament. But we mistakenly depict many things as trends moving in some direction. We take the "full house" of variation in a system and try to represent it as a single number, when in fact what we should be doing is studying the variation as it expands and contracts. If you look at the history of the variation in all its complexity, then you see there's no trend.
Stephen Jay GouldThe basic formulation, or bare-bones mechanics, of natural selection is a disarmingly simple argument, based on three undeniable facts (overproduction of offspring, variation, and heritability) and one syllogistic inference (natural selection, or the claim that organisms enjoying differential reproductive success will, on average, be those variants that are fortuitously better adapted to changing local environments, and that these variants will then pass their favored traits to offspring by inheritance).
Stephen Jay GouldBut we all recognise the primary foible of frail humanity - our propensity for embracing hope and shunning logic, our tendency to believe what we desire rather than what we observe.
Stephen Jay GouldThe literal record was not a hopelessly and imperfect fraction of truly insensible gradation within large populations but an accurate reflection of the actual process identified by evolutionists as the chief motor of biological change. The theory of punctuated equilibrium was, in its initial formulation, little more than this insight adumbrated.
Stephen Jay GouldBut our ways of learning about the world are strongly influenced by the social preconceptions and biased modes of thinking that each scientist must apply to any problem. The stereotype of a fully rational and objective scientific method, with individual scientists as logical (and interchangeable) robots, is self-serving mythology.
Stephen Jay Gould