Prior to about 100,000 years ago, humans didn't travel much. Our population shifted and spread geographically much like how populations shift for any species, which depends on things like environmental events or ecological changes. But then, at some crucial juncture, everything changed. Humans began migrating at breakneck speed, spreading across continents and major environmental barriers, until eventually inhabiting nearly every ecological niche imaginable.

So what happened 100,000 years ago that suddenly gave our species such an insatiable sense of wanderlust? New research by Dr. Penny Spikins, an archaeologist at the University of York, offers a rather theatrical explanation. She claims that around this time, humans developed an advanced propensity for betrayal, reports

In other words, humans had evolved into exceptional drama queens. Moral disputes motivated by broken trust and a sense of betrayal became so frequent among human groups that we were driven apart from one another. Rapid human migration was a desperate attempt to flee from our rivals. You might say the story of ancient human migration was like an epic Greek tragedy, the plot escalating as one betrayal led to the next.

If Spikins' theory doesn't explain human migration, it may at least explain our love of soap operas.

"Active colonizations of and through hazardous terrain are difficult to explain through immediate pragmatic choices," said Spikins. "But they become easier to explain through the rise of the strong motivations to harm others even at one's own expense which widespread emotional commitments bring. Moral conflicts provoke substantial mobility — the furious ex ally, mate or whole group, with a poisoned spear or projectile intent on seeking revenge or justice, are a strong motivation to get away, and to take almost any risk to do so."

The real paradigm shift being evoked here involves how we think of ourselves as a human species. Previous theorists have been prone to explain rapid human migration by appealing to our more favorable traits, such as our propensity for curiosity. Spikins is instead reminding us that human nature is rife with adverse traits too: we are master deceivers, liars, backstabbers. Our dark side may have driven us just as much as our complimentary traits, if not more so.

"While we view the global dispersal of our species as a symbol of our success, part of the motivations for such movements reflect a darker, though no less 'collaborative', side to human nature," said Spikins.

Bryan Nelson ( @@brynelson ) writes about everything from environmental problems here on Earth to big questions in space.

Human betrayal drove rapid spread of our species
The history of human migration might have played out like an epic Greek tragedy, driven by betrayal, lies and broken trust.