Sculpture from Egypt, c. 1500–1300 BC, when hippos were still widespread along the Nile. Credit: Andreas Praefcke, Wikimedia Commons, public domain

Depictions of animals in ancient Egyptian artifacts have helped scientists assemble a detailed record of large mammals that lived in the Nile Valley for the past 6,000 years. A new analysis of this record by SFI Omidyar Postdoctoral Fellow Justin Yeakel and collaborators shows that species extinctions, probably caused by a drying climate and growing human population in the region, have made the ecosystem progressively less stable.

The study, published in PNAS, finds that local extinctions of mammal species led to a steady decline in the stability of the animal communities in the Nile Valley. When there were many species in the community, the loss of any one species had relatively little impact on the functioning of the ecosystem, whereas it is now much more sensitive to perturbations.

The study had its origins in 2010, when Yeakel (then a graduate student at UC Santa Cruz) visited a Tutankhamun exhibition in San Francisco with coauthor Nathaniel Dominy (then an anthropology professor at UC Santa Cruz and now at Dartmouth). 

"We were amazed at the artwork and the depictions of animals, and we realized they were recording observations of the natural world...we started thinking about how we could take advantage of those records," says Yeakel, the paper's lead author.

The research was conducted while Yeakel was at UC Santa Cruz. His collaborators include Mathias M. Pires, Lars Rudolf, Nathaniel J. Dominy, Paul L. Kochi, Paulo R. Guimarães, and Thilo Grosse.

Read the paper in PNAS (September 8, 2014)

Read the article in The Financial Times (October 3, 2014)

Read the UC Santa Cruz news release (September 8, 2014)

Read the article in Science (September 8, 2014)

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Read the United Press International article (September 8, 2014)

Read the article in The Mail Online (September 8, 2014)

Read the article in Nature (August 8, 2013)

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Read the article in Resilience (September 15, 2014)

Read the article in Archaeology (December 15, 2014)