Life shows no trend to complexity in the usual sense-only an asymmetrical expansion of diversity around a starting point constrained to be simple.
Stephen Jay GouldNatural 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 GouldOrchids were not made by an ideal engineer; they are jury-rigged from a limited set of available components.
Stephen Jay Gould