"Evolution is a natural drift ... nor is [any] guiding force needed to explain [it]. ... Evolution is somewhat like a sculptor with wanderlust: he goes through the wood collecting a thread here, a hunk of tin there, a piece of wood here, and he combines them in a way that their structure and circumstance allow, with no other reason than that he is able to combine them. And so, as he wanders about, intricate forms are being produced; they are composed of harmoniously interconnected parts that are a product not of design but of a natural drift." [Humberto Maturana & Francisco Varela, The Tree of Knowledge (1987) p 117.]
This argument shifts explanation of biological features or behaviour pattern away from teleology (patterns are caused by the evolutionary advantage that the pattern confers) towards material cause and formal cause (patterns exist because they were available and consistent with the prevailing structural coupling).
Evolutionary psychologists like to argue sweeping propositions like "men tend to behave like this towards women because it gets them a greater number of descendents" or "women tend to behave like this towards men because it ensures greater survival and prosperity for their children", as if all normal men displayed this behaviour pattern, and all normal women displayed that one. They also like to argue that certain physical types are more "attractive" to the opposite sex. The fact is that men and women display an extraordinary diverse range of behaviour patterns, as well as physical shapes and sizes, nearly all of which are consistent with the continued existence of the individuals and (if they exist) their progeny.
Meanwhile, the fact that sexual pairing is not restricted to those who fit the evolutionary psychologists' stereotypes could be interpreted as evidence for a deeper evolutionary purpose than the kind of purpose recognized by evolutionary biologists.
