Evolution in human culture, including political development, is fundamentally different than evolution in the purely biological realm, Haas noted. In biology, variations are randomly produced. But in cultural evolution, variations are not randomly produced. The process of natural selection is more random than that. In human cultural systems, variations are not random, Haas continued.
Humans are tinkerers.
They tinker to make things better. A human may plant two or three seeds in a hole instead of one, for example, just to see what happens. If he gets more crop, then he will continue planting more than one seed and the agricultural system has evolved another step. Haas has joined with several other anthropologists and archaeologists in the SFI working group on Culture as an Adaptive System. You have to have thinking agents directing variation.