Hard to believe that the Indo-Europeans, negros, and the Japanese are descended from Adam and Eve.
https://genographic.nationalgeographic.com/human-journey/According to the genetic and paleontological record, we only started to leave Africa between 60,000 and 70,000 years ago. What set this in motion is uncertain, but we think it has something to do with major climatic shifts that were happening around that timea sudden cooling in the Earths climate driven by the onset of one of the worst parts of the last Ice Age. This cold snap would have made life difficult for our African ancestors, and the genetic evidence points to a sharp reduction in population size around this time. In fact, the human population likely dropped to fewer than 10,000. We were holding on by a thread.
It is the survivors of this near extinction who appear to have made some form of fundamental technological, social or evolutionary leap that allowed humanity to break the prior constraints which had kept its population small and limited to Africa.
http://blog.23andme.com/news/the-first-population-explosion-human-numbers-expanded-dramatically-millennia-before-agriculture/The authors found genetic evidence for a surge in human population size about 40,000 to 50,000 years ago. This period, just after humans first set foot outside Africa, is of great interest to archaeologists because it coincides with a dramatic increase in the sophistication of human behavior. People began crafting tools from bone, burying their dead and fashioning clothing to keep themselves warm in cool climates. They developed complex hunting techniques, and created great works of art in the form of cave paintings and jewelry.
The archaeological record also shows that during this time, humans began hunting more dangerous prey and more easily exploiting small game like rabbits and birds. They traveled farther than they had before, perhaps due to the growth of long-distance trade routes the first of their kind. Jared Diamond, author of The Third Chimpanzee, calls this period The Great Leap Forward, when humans burst forth culturally finally separating themselves from their evolutionary cousins.
The exact cause for these changes in human behavior may never be known. Some believe a simple genetic mutation or that the evolution of language could have sparked such a dramatic change. But what we do know now, thanks to this new genetic research, is that like the (much later) invention of agriculture this explosion of innovation was accompanied by population growth.
In the Biblical story of Adam and Eve Our ancestors are warned not to eat of the fruit of the Etz Hadaath, the Tree of Knowledge for as long as They did not eat of it, they were like angels who do only good. The fruit of the Tree of Knowledge, however, changed this.
People interpret this story in different ways but I tend to view it as instructive parable. A primitive species in a natural competitive equilibrium can be thought of as living in a garden. Breaching this equilibrium requires knowledge. Sometime around 70,000 years ago our ancient ancestors acquired the knowledge needed to explosively overcome the constraints that had previously kept our numbers and progress in check. We ceased living as a part of nature and began to dominate it.
This breakthrough led to the spread of humanity throughout the world and possibly made inevitable the later agricultural revolution. Having broken our natural constraints we are now compelled to continue our relentless climb up the tree of knowledge until we grow knowledgeable enough to voluntarily establish new ones for ourselves.