When and why our ancestors started walking upright is a question that has kept our minds busy for a very long time
Quashing the previous study that said climate changes forced our ancestors to walk upright, a new study has claimed that it was the geographical conditions that helped a man to evolve and start walking on two legs.
In a study that has found its place in archaeological journal Antiquity, a team of archaeologists have stated man started walking upright due to the varied terrain as a result of the volcanic eruptions and shifting tectonic plates in East and South Africa.
In a press release, Isabelle Winder, study co-author, at the University of York archaeologist said: â€œThe broken, disrupted terrain offered benefits for hominins in terms of security and food, but it also proved a motivation to improve their locomotor skills by climbing, balancing, scrambling and moving swiftly over broken ground – types of movement encouraging a more upright gait. This development would have conferred benefits that extend far beyond locomotion. Walking on two legs frees up the hands, allowing for the use of tools and, eventually, bigger brains. And the complex landscape could have made our ancestors smarter. The varied terrain may also have contributed to improved cognitive skills such as navigation and communication abilities, accounting for the continued evolution of our brains and social functions such as co-operation and team work. ”
It may be recalled that in 1961 anthropologist Gordon W. Hewes had assumed that the time our ansectors got away from chimps and apes, the environment in Africa underwent a drastic change some 2.5 million years ago, thus forcing the australopithecine ancestors descended from the trees and venture out into the open savanna, thus making some resources scarce. â€œIn order to survive that had to collect the resources and carry them to their normal habitat. And there would have been no better way to do that than to stand upright and use their hands to hold whatever they needed to transport,â€ Hewes maintained.
This theory was further substantiated by a team of researchers from the United States, England, Japan and Portugal spent weeks watching the chimpanzees in Guinea in West Africa to support the theory, one of several leading explanations for why humans became bipedal somewhere between three and six million years ago. The researchers observed chimpanzees in their natural habitat to see how they would move about if they needed to carry something.
In the study published in Current Biology, Brian Richmond of George Washington University said: “These chimpanzees provide a model of the ecological conditions under which our earliest ancestors might have begun walking on two legs. Something as simple as carrying — an activity we engage in every day — may have, under the right conditions, led to upright walking and set our ancestors on a path apart from other apes that ultimately led to the origin of our kind.”
However now with the new theory maintaining that instead of the cimate, our earliest ancestors – were attracted to the rugged terrain created by volcanoes and earthquakes of the Pliocene era, 2 million to 5 million years ago. Though the rocky outcrops and gorges offered shelter and hunting opportunities, it required scrambling and climbing and the ability to move quickly over broken ground. It also encouraged a more upright posture and an improved hand and arm agility.