YORK, ENGLAND—Human ancestors migrated when population increases or ecological changes forced them to look for new, similar living environments. But around 100,000 years ago, people began to disperse across environmental barriers into new regions at a much faster rate. Penny Spikins of the University of York thinks that developing human emotional relationships, and the resulting moral disputes and betrayals among groups of people, may have motivated them to make such risky moves into new territories. “Active colonizations of and through hazardous terrain are difficult to explain through immediate pragmatic choices. 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,” she said in a press release. “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,” she said. To read about how insects spread around the world, go to "Ant Explorers."
