According to the Torah, God commanded Homo Sapiens to “fill up planet Earth” (Genesis 1:28);
and as a species we have most certainly done that. But what motivated prehistoric mankind to spread out throughout the entire world, in the evolutionary rapid time of less than 70-80,000 years?
Homo Erectus originated somewhere in East Africa almost two million years ago, and then slowly spread out to inhabit South Africa, the southern parts of Europe (Spain and Italy), the Caucasus, India, China, and Indonesia over the next almost one million years.
Homo Sapiens reached Indonesia and Australia within 50,000 years of its exodus from Africa.
New research by a paleoanthropologist at the University of York suggests that moral and emotional reasons, especially betrayals of personal and communal trust, are the best way to understanding the rapid spread of our own species around the world.
Dr Penny Spikins, says that the speed and character of human dispersals changed significantly about 90-100,000 years ago.
Before then, movements of pre Homo Sapiens species were slow and largely due to environmental events, population increases, or ecological changes. Then, relatively quickly, human populations spread with remarkable speed and across major environmental barriers.
Dr Spikins, relates this change to changes in human moral, spiritual, and emotional relationships. In research published in Open Quaternary (PHYS.org November 24, 2015), she says that neither population increase nor ecological changes provide an adequate explanation for patterns of human movement into new regions which began around 90-100,000 years ago.
Spikins suggests that as social and personal commitments to others became more essential to group survival, human groups became more motivated to identify and punish those individuals who cheat. Moral disputes motivated by broken trust and/or a sense of betrayal became more frequent and motivated early humans to put distance between themselves and their rivals.
The religious and emotional bonds which held populations together in crisis, had a darker side in heartfelt reactions to betrayal which we still feel today. Larger social networks made it easier to find distant allies with whom to start new colonies, and more efficient hunting technology meant that anyone with a grudge and a weapon was a danger, but it was human values and emotions which provided a force of repulsion from existing occupied areas, which we do not see in other animals.
The expansion of Homo Erectus out of Africa into Asia around 1.8 million years ago appears to have been caused by the need to find more large scale grasslands. After 90-100,000 years ago, however, dispersal into distant, risky and inhospitable areas became relatively more common compared with movements into already occupied regions.
Human populations moved into very cold regions of Northern Europe, crossed significant river deltas such as the Indus and the Ganges, deserts, tundra and jungle environments and even made significant sea crossings to reach Australia.
In other words, God’s commandment to “Fill up planet Earth’ is followed by Eve and Adam’s decision to internalize (eat) the fruit the morality tree; and gain knowledge of good and evil. This leads to moral conflicts that often provoke substantial mobility—the furious ex ally, mate or whole group, intent on seeking revenge or justice, are a strong motivation to run away, and to take almost any risk to do so.
While religion is a powerful force binding people together, it also can be a strong force that gives courage and hope to dissenters, who abandon their birth community to go forth to a strange land, as was the case with Abraham and Sarah:
“The Lord had said to Abram, “Go from your country, your people, and your father’s household, to the land I will show you, and I will make you into a great nation. I will bless you, I will make your name great, and you will become a blessing.(Genesis 12:1-2)
As Charles Townes, 1964 Nobel Prize in Physics said: “My own view is that, while science and religion may seem different, they have many similarities, and should interact and enlighten each other,”
Spikins research is a good example of Townes’ thought.