I have a debt, a loyalty to the museum; the best place for me to do what I wanted to do.

The 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.

The meaning that we are seeking in evolution is its meaning to us, to man. The ethics of evolution must be human ethics. It is one of the many unique qualities of man, the new sort of animal, that he is the only ethical animal. The ethical need and its fulfillment are also products of evolution, but they have been produced in man alone.

It is inherent in any definition of science that statements that cannot be checked by observation are not really saying anything or at least they are not science.

Species evolve exactly as if they were adapting as best they could to a changing world, and not at all as if they were moving toward a set goal.

To put it crudely but graphically, the monkey who did not have a realistic perception of the tree branch he jumped for was soon a dead monkey-and therefore did not become one of our ancestors.

...the argument from absence of transitional types boils down to the striking fact that such types are always lacking unless they have been found.