The great Carl Sagan noted that if we compress the history of time (from the Big Bang to the present) to a year, then Earth came along at about the 255th day of that year, and we came down from the trees sometime in the last 12 minutes of that year. We are the last episode in the long history of evolution. Our DNA tells a fascinating story of how intelligence started to spread around the globe just about 60,000 years ago in Africa (which in the compressed cosmic calendar is about 2 minutes before midnight of Dec 31). The story is frought with great suffering on one hand, but also great triumphs on the other.
Just before we acquired our intelligence, we were agile tree climbers, able to evade predators by jumping from one tree branch to another. We now have come down from the trees (and, some claim, have started to mow down the trees to the detriment of our habitat).
Look at how far we have come since then! Our new-found intelligence has given us all these tools: from the wheel, to fire, to rockets that land us on the moon. We have gone out of the caves and now live and work in tall buildings. We drive cars and can fly to anywhere. We have radio, television, and the computer. We now control our destiny and can even direct evolution itself to our design.
And the story lives on. What next? It is difficult to foretell because the story is also about the struggle between the forces of good and the forces of chaos. As much as good has triumphed in the past, chaos is ever-present to take back what the good has won. For the paranoid, we are not much better off from when we cowered in our caves, protected only by our puny weapons against predators, both human and non-human. Today there is much to be afraid of. Will our progeny experience extreme chaos?
Perpetual Cycle of Life 