Was Humanity’s Trek Out of Africa A Weekend Getaway?

STORY BY James Sullivan

Published: December 22, 2013

The apes that have been linked to all modern humans as our ancestors via mitochondrial DNA evidence have been long thought to have migrated through the African continent, first originating in the deserts before the land became too harsh to support life. However, a burning question is why they began their migration – was it due to sudden unforgiving terrain, that perpetually placed them at odds with unusual surroundings and merciless predators and extremes, or were these departures gradual ones, happening as a few members of the tribe sought out new frontiers before traveling ahead? To answer the title, I would say probably not, but thanks to some recent studies, apes like orangutans and chimpanzees have demonstrated the ability to make plans, particularly migratory journeys, suggesting a common learned memory that may have passed along the species millions of years ago.

Among the new evidence that supports the migratory routes of our ancestors across the Sahara is the remains of the River Irharhar to the west, which according to graphic topography maps analyzing the summers just before the Ice Age 100,000 years ago, had the unusual property of flowing from south to north and provided humid corridors that they may have followed, leading them to an abundance of food and verdant ground, lush forests that would have sheltered them from predators during their travels. However, recent studies have suggested that our distant primate cousins have, perhaps out of inevitability, developed the ability to build plans. This behavior is not only limited to living out on the dangerous plain either, as the chimp Santino of the Furuvik Zoo in Sweden demonstrated. When the keepers brought Santino out to his daytime enclosure, he became belligerent to the zoo’s visitors. He began to stockpile decorative stones from the enclosure before the zookeepers came for him to bring him into his enclosure by night. The next day, he would hurl these stones at the visitors, defending his territory in a ferocious display.

Fortunately, Santino was relocated to a new, fenced in enclosure before anyone was harmed, and showed no more signs of aggression. However, even outside of domestic settings like a zoo, apes such as Arno the wild orangutan have been known to make use of their surroundings. Universitas Indonesia recently published a study that followed Arno and 15 other male orangutans, concerning loud echoing calls that they made back and forth to their families at night, from the trees. The resonance of these calls was particularly important, as they indicated times of day for travel and when it was most preferable. These would be repeated until the orangutans changed calls, indicating a change in their plans of direction, and the calls grew louder to indicate to Arno’s rivals to stay out of his family’s way. Twelve hours later, the orangutans would be making similar calls, indicating the directions in which they traveled, an indication of one of the first successful studies of long term planning and itinerary in primates. It seems to be a mistake to take offense at the idea that we’re related to apes, as evidence in the case of Santino or Arno and his family show them to be highly social and intelligent beings. The creatures that devised expeditions out of the deserts were hardly unlike them, hairy but nonetheless intelligent beings, who had they not been so successful in their articulation, it is doubtful that humanity would be thriving today. 

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