There is of course no such thing as Darwinism, any more than there is Newtonism or Mendelism; evolution is simply a confirmed part of science. Nevertheless, there is Vulgar Darwinism, the belief that our nature as evolved beings rigidly determines our behavior in ways that coincidentally resemble the most cherished beliefs of the speaker. Competition and cooperation are two popular oversimplifications, but the term evolutionary psychology usually goes to the form that proclaims sexual dimorphism as the Truth of Our Nature that it is simultaneously virtuous and scientifically correct to follow and enforce.
I await the arrival of Ev. Psych's own Frederick C. Crews,* the former true believer who will turn on the old faith as Crews did with the teachings of Pope Sigmund, and be so nasty as almost to inspire sympathy. Until then, we have Amanda Marcotte.
*Or as Chris Berman might call him, Frederick "Won't You Let Me Take You on a" C. Crews