Natural selection is just three factors - over-production, variation, and inheritance combined to produce adaptation to changing local environments. It's not a principle or progress; it's just a principle of local adaptation. You don't make better creatures in any cosmic sense; you make creatures that are better suited to the changing climates of their local habitats.
Stephen Jay GouldEinstein's theory of gravitation replaced Newton's, but apples did not suspend themselves in mid-air, pending the outcome. And humans evolved from apelike ancestors whether they did so by Darwin's proposed mechanism or by some other yet to be discovered.
Stephen Jay GouldThe center of human nature is rooted in ten thousand ordinary acts of kindness that define our days.
Stephen Jay GouldScience is all those things which are confirmed to such a degree that it would be unreasonable to withhold one's provisional consent.
Stephen Jay Gould