This essay was too incoherent to work well in my B&C blog roundup, but I wanted to retain this clip. It's by the lucid writer Cullen Murphy of the Atlantic Monthly on the "built-in conservatism" of human beings:

Over the ages and across countless cultures our beds have looked like beds, our chairs like chairs, our houses like houses. Our active lives are defined by the body's thresholds of heat and cold, pain and pleasure, energy and fatigue. Our eyesight is fixed within a specified range (better than that of bats, inferior to that of eagles), and so is our hearing. The sheer physical demands of hauling the body to work seem to be influenced by some inherent governor: a famous study of commuting, for instance, suggested that although distances have changed with technological advances, people in all eras and cultures have budgeted about the same amount of time for daily travel (on average, about half an hour one way). ... I retain considerable faith in the staying power of our pre-posthuman selves. Enhancement arrives with the audacity of Napoleon; the body responds with the inertial resistance of those two great Russian generals, January and February.
http://www.theatlantic.com/issues/2003/05/murphy.htm