How about another theory: The light entered the world in a huge way two millennia ago, fostering a new way of looking at fellow man: instead of competing with and vanquishing ones enemy, we’re now to love him. Setting a whole new standard, spurring waves of charitable volunteer work and donations of wealth and time, promoting selflessness, the building of hospitals, orphanages, educational system/universities, strides in learning and science and the pursuit of excellence in general, offering light and hope and order in an otherwise dark and dismal and angry and confused and ultimately meaningless and temporary world/life.
People are not mere biobots, compelled by the latest evolutionary forces to change in one way or another. We change as a matter of choice, compelled , if anything, by the greater good, the higher ideal, that we perceive and then reason upon. What if Christianity actually laid the foundation for such ideals, deep down, the ideals that now engender movements for such things as civil rights, feminism, humanism, etc, even if the horse may end up biting the hand that fed it at times? If anything we are evolving, with the help of grace, towards a higher state, but only in the mental/spiritual sense rather than the natural one, or at least some are doing so while others may remain in as dark a state as humankind as ever been. Wheat and tares, light and darkness, our challenge, our choice. Just some thoughts.