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We have made one kind of bargaining with nature: our children will be difficult to improve, but their capacity for the new study will greatly enhance the chance of survival of the species. In addition, the man has, in recent 10% of our existence, not only extra-curricular genetic invention, and in vitro knowledge:  information stored outside agencies, which writing is the most obvious example.           Books, Culture and Evolution     Jacob Bronowski was one of a small group of men and women in any age who find all of human knowledge — the arts and sciences, philosophy and psychology — interesting and accessible. He was not confined to a single discipline, but ranged over the entire panorama of human learning. His book and television series, The Ascent of Man, are a superb teaching tool and a remarkable memorial; they are, in a way, an account of how human beings and human brains grew up together. His last chapter/episode, called "The Long Childhood," describes the extended period of time — longer relative to our lifespan than for any other species — in which young humans are dependent on adults and exhibit immense plasticity — that is, the ability to learn from their environment and their culture. Most organisms on Earth depend on their genetic information, which is "prewired" into their nervous systems, to a much greater extent than they do on their extragenetic information, which is acquired during their lifetimes. For human beings, and indeed for all mammals, it is the other way around. While our behavior is still significantly controlled by our genetic inheritance, we have, through our brains, a much richer opportunity to blaze new behavioral and cultural pathways on short time scales. We have made a kind of bargain with nature: our children will be difficult to raise, but their capacity for new learning will greatly enhance the chances of survival of the human species. In addition, human beings have, in the most recent few tenths of a percent of our existence, invented not only extra-genetic but also extrasomatic knowledge: information stored outside our bodies, of which writing is the most notable example.   The time scale for evolutionary or genetic change is very long. A characteristic period for the emergence of one advanced species from another is perhaps a hundred thousand years; and very often the difference in behavior between closely related species — say, lions and tigers — do not seem very great. An example of recent evolution of organ systems in humans is our toes. The big toe plays an important function in balance while walking; the other toes have much less obvious utility. They are clearly evolved from fingerlike appendages for grasping and swinging, like those of arboreal apes and monkeys. This evolution constitutes a respecialization — the adaptation of an organ system originally evolved for one function to another and quite different function — which required about ten million years to emerge. (The feet of the mountain gorilla have undergone a similar although quite independent evolution.) But today we do not have ten million years to wait for the next advance. We live in a time when our world is changing at an unprecedented rate. While the changes are largely of our own making, they cannot be ignored. We must adjust and adapt and control, or we perish.   Only an extragenetic learning system can possibly cope with the swiftly changing circumstances that our species faces. Thus the recent rapid evolution of human intelligence is not only the cause of but also the only conceivable solution to the many serious problems that beset us.           — Carl Sagan, The Dragons of Eden               Indexes/10