The discovery that chimpanzees use tools to dig up edible tubers might help us understand our human origins better.
Anthropologist Jim Moore, of the University of California San Diego, studies chimps in the Ugalla region of Tanzania. A 2007 study that he helped guide provides the first evidence that chimps use tools to forage for tubers.
Jim Moore: A lot of models of human evolution have emphasized the importance of some kind of technology that allows us to do things that other animals – other primates anyway – haven’t been able to do. And one of those, perhaps the central one is the use of sticks to dig up roots and tubers.
Tubers such as sweet potatoes and cassava were important foods for early hominids, and are still important foods in human societies today. Moore told EarthSky that the Ugalla chimps forage for tubers in much the same way our human ancestors might have.
Jim Moore: Finding chimpanzees doing a very primitive, very simplified version of this presents us with a way of understanding how this behavior – so important to modern human foragers – might have gotten started.
It’s a finding that, Moore said, complicates the line between human and non-human, but that might help us understand our own origins.
Jim Moore: It gives us a way of studying the behavioral side of the origin of something that was critical in allowing us to expand around the world, and allowing us to become who we are.
Adriana Hernandez-Aguilar, a graduate student at the University of Southern California at the time, made the observations of tuber-digging chimps during her dissertation research. The other co-author on the study, Travis Pickering, was involved with the tool analysis. Chimps have been known to use tools in a wide variety of contexts – poking grass stems into termites mounds and beehives, for example. But this 2007 study is the first evidence that chimps use tools to forage for tubers.
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University of California
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Eleanor Imster has helped write and edit EarthSky since 1995. She was an integral part of the award-winning EarthSky radio series almost since it began until it ended in 2013. Today, as Lead Editor at EarthSky.org, she helps present the science and nature stories and photos you enjoy. She also serves as one of the voices of EarthSky on social media platforms including Facebook, Twitter and G+. She and her husband live in Tennessee and have two grown sons.