The science of systematics has long been affected by profound philosophical preconceptions, which have been all the more influential for being usually covert, even subconscious.
George Gaylord SimpsonIt remains true, as every paleontologist knows, that most new species, genera, and families, and that nearly all categories above the level of families, appear in the record suddenly and are not led up to by known, gradual completely continuous transitional sequences.
George Gaylord SimpsonI have a debt, a loyalty to the museum; the best place for me to do what I wanted to do.
George Gaylord SimpsonA rill in a barnyard and the Grand Canyon represent, in the main, stages of valley erosion that began some millions of years apart.
George Gaylord SimpsonThe earliest and most primitive known members of every order already have the basic ordinal characters, and in no case is an approximately continuous sequence from one order to another known. In most cases the break is so sharp and the gap so large that the origin of the order is speculative and much disputed.
George Gaylord Simpson