Much of human history has consisted of unequal conflicts between the haves and the have-nots.

The southward advance of native African farmers with Central African crops halted in Natal, beyond which Central African crops couldn't grow - with enormous consequences for the recent history of South Africa.

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.

Twelve thousand years ago, everybody on earth was a hunter-gatherer; now almost all of us are farmers or else are fed by farmers. The spread of farming from those few sites of origin usually did not occur as a result of the hunter-gatherers' elsewhere adopting farming; hunter-gatherers tend to be conservative.... Instead, farming spread mainly through farmers' outbreeding hunters, developing more potent technology, and then killing the hunters or driving them off of all lands suitable for agriculture.

The survival rate of Dr Burton's patients approximately doubled the maximum survival rate of conventionally treated patients. Had these findings pertained to a chemotherapy drug instead of IAT, massive amounts of funding would have been allocated to investigate the drug. Once again, the politics of cancer barred a potentially valuable treatment from reaching the public.

Much of human history has consisted of unequal conflicts between the haves and the have-nots.

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