How is cultural change analogous to biological evolution and what important limitations are there to this analogy?
At look at the history of countries that were colonized by other cultures, specifically the European empires, reveals that the permanency of any alteration in the native culture is not significant. For once these countries became independent of European rule, and the cultural rule was no longer present, the evidences of such influences diminished rather rapidly.
With regard to biological changes, they can not be forced and effectively as rapidly as cultural changes; however, once effected, the biological changes are more lasting, and sometimes even permanent.
Given that I am not a biologist, I may be slightly off, but in my mind, both are very similar except in terms of a time frame necessary for change. Both evolutionary change and cultural generally are in response to changes in environment or simply to improve a certain type of interaction or existence in standard conditions. People change to fit their surroundings and to gain maximum benefit from the opportunities around them so too do animals and other organisms.
The difference, I think, lies in the time frame necessary for evolutionary change being longer than that necessary for cultural changes.
Cultural and biological change are similar enough that we have the idea of Social Darwinism. They are similar because different societies have different cultural values. These societies compete with one another economically and militarily and culturally. One side generally "wins." So it becomes possible to imagine that the cultural values of the "winning" society are better than those of the "losing" society. In such a view, the better cultures win and so culture will improve over time as the better ones win.
There are many problems with this. Just to take one obvious one, why did the United States defeat Japan in WWII? Was it because the US had a better culture? Or was it because they had more resources to use to create and deploy weapons against the Japanese? If we just say that culture is what causes one society to win and another to lose, we miss out on these other factors that can impact the outcome of these competitions.
I believe that cultural changes are analogous to biological changes to the extent that cultures that change or evolve in ways that enable the people in that culture better prepared to deal with the environment and circumstances within which the society exists, have greater chances of becoming more powerful and of growing in size. However, it should be realized that the environment and circumstances faced by a society is not just dependent on the physical locations. People in general have greater tendency to migrate to other areas. Also, the circumstances faced by a highly successful and well develop society with an advanced but peaceful civilization may find itself incapable of resisting conquest by people with a relatively less developed culture which relies more on war and violence.