One way to explain the complexity and unpredictability of historical systems, despite their ultimate determinacy, is to note that long chains of causation may separate final effects from ultimate causes lying outside the domain of that field of science.

All human societies go through fads in which they temporarily either adopt practices of little use or else abandon practices of considerable use.

The rate of human invention is faster, and the rate of cultural loss is slower, in areas occupied by many competing societies with many individuals and in contact with societies elsewhere.

It invites a search for ultimate causes: why were Europeans, rather than Africans or Native Americans, the ones to end up with guns, the nastiest germs, and steel?

History as well as life itself is complicated -- neither life nor history is an enterprise for those who seek simplicity and consistency.

Today Charles Darwin is best known for establishing the fact of evolution and for recognizing the major role of natural selection in driving it.

Biology is the science. Evolution is the concept that makes biology unique.