Organisms are not billiard balls, propelled by simple and measurable external forces to predictable new positions on life's pool table. Sufficiently complex systems have greater richness. Organisms have a history that constrains their future in myriad, subtle ways.

Asian Homo erectus died without issue and does not enter our immediate ancestry (for we evolved from African populations); Neanderthal people were collateral cousins, perhaps already living in Europe while we emerged in Africa... In other words, we are an improbable and fragile entity, fortunately successful after precarious beginnings as a small population in Africa, not the predictable end result of a global tendency. We are a thing, an item of history, not an embodiment of general principles.

Obsolescence is a fate devoutly to be wished, lest science stagnate and die.

Skepticism is the agent of reason against organized irrationalism--and is therefore one of the keys to human social and civic decency.

The invalid assumption that correlation implies cause is probably among the two or three most serious and common errors of human reasoning.

Speciation does not necessarily promote evolutionary change; rather, speciation 'gathers in' and guards evolutionary change by locking and stabilization for sufficient geological time within a Darwinian individual of the appropriate scale. If a change in a local population does not gain such protection, it becomes-to borrow Dawkins's metaphor at a macroevolutionary scale-a transient duststorm in the desert of time, a passing cloud without borders, integrity, or even the capacity to act as a unit of selection, in the panorama of life's phylogeny.

Mary Anning [is] probably the most important unsung (or inadequately sung) collecting force in the history of paleontology.