Forgive me if I don't use of the functionality which veterans in blog ville use (links to sites,pictures & complex fonts)
In order to attract a higher quality mate, a common evolutionary trait we developed was the beauty in symmetry. Having this trait, it gave us the ability to point out health in potential mate.
Natural selection began and healthy genes owners mated were provided with the first right to refuse.
In time, societies became more complex thus resulting in more stringent rule to stay on top. Societal values came into play in deciding potential mates. How this was done resulted from a development where the next generation is chosen by a balance mix of parents with symmetric traits and characteristics that push up the social ladder. Example, women with hips & breast that fits into the valuation profile of that society are termed as "sexy". By birth and looks the woman has earned her looks to push her generation through time.
We fast forward to today. The result of many decision made in the past is becoming more evident. The disparity between the rich & the poor is getting wider. With this disparity, the possibility of a genetically class of haves & have-nots is becoming more apparent.The poor are so not because they cultivated subsistence living, but as a result issues stated earlier (symmetric look or skills). This affects how they appreciate things and their value system (separation their culture from the already accepted standard). These variation could generally result in some form of mutation. Naturally, it results to the divided groups settling into either upper and lower class (based on economic factors) and presenting some tough decisions to the off-springs those "migrating" from one class to the other.
Unconsciously, the society fate in history has been natural selected to the path of extinction.
One thing I feel is common about the evolution of species is extinction. Evolution results from a range of factors. I think our extinction will result from internal discord. A system divided within itself cannot stand.