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Adventures in the Rift Valley: Interactive
Since 1985, Smithsonian scientists have worked with the National Museums of Kenya to excavate the landscapes of Olorgesailie, Kenya. See how the team searches for evidence to answer questions about how human ancestors lived during the past one million years.
How did early humans survive?
By eating plant foods.
Plenty of stone tools were discovered in this dig, around 1 million years old, but no animal bones were found. Dozens of the stones had flat surfaces with shallow pits, like the one on the right. The pits contained many phytoliths - microscopic particles that plants make in their tissues and cells. These phytoliths show that early humans used the stones as hammers and anvils to crush nuts, underground tubers, and other plant foods.
By avoiding dangerous predators whenever possible.
A cluster of stone tools and butchered bones of zebras and other animals were found in this dig, around 990,000 years old. Even though early humans ate meat at this site, dangerous predators avoided it. Not a single tooth mark made by a hyena or other carnivore was found here. By this date, early humans may have become dangeous, or were so good at eating all the meat and bone marrow that carnivores had little reason to visit.
By being social.
At this excavation, an elephant skeleton was found surrounded by more than 2,300 stone tools, along with cut marks on the bones. The butchery of this elephant provided lots of meat. The job probably required the cooperation of most all the members of the social group.
By eating meat.
Early humans left lots of evidence of animal butchery and cracking open bones to eat the nutritious marrow. This fragment of fossil rib from a large antelope, around 625,000 years old, shows butchery cut marks that early humans inflicted by using a sharp stone tool.
By finding shade under large trees.
Excavators unearthed many stone tools at this site, along with evidence of tree roots indicating that a larg tree grew at the site. In the hot equatorial sun, finding shade and staying cool during the day was as important to survival as eating food and drinking water. Many stone toors surround this remnant of a tree stump and roots at this 625,000-year-old site
By making stone tools.
At this dig site, excavators unearthed a quarry where early humans found material for making stone tools. By striking the hardenend volcanic rock with large hammerstones, early humans broke off huge flakes, which they further struck around the edge time and again to make handaxes. Striking a large flake was the first step in making a handaxe, as seen by this huge scar at the quarry.