Let me give you my own personal definition of the basic method of economic theory. To me, it seems that what we know as economics is the study of those phenomena that can be understood as emerging from the interactions among intelligent, self-interested individuals. Notice that there are really four parts to this definition. Let's read from right to left. This is not to deny the relevance of higher levels of analysis, but they must be grounded in individual behavior.
Methodological individualism is of the essence.
The individuals are self-interested. There is nothing in economics that inherently prevents us from allowing people to derive satisfaction from others' consumption, but the predictive power of economic theory comes from the presumption that normally people care about themselves. Hundred-dollar bills do not lie unattended in the street for very long. OK, that's what economics is about. The answer, basically, is that evolutionists share three of the four concerns.