Egyptians Kept Animal Extinction on Record

By studying ancient Egyptian artifacts and records, experts have been able to trace the increasing instability of the Nile Valley ecosystem as far back as 6,000 years ago, blaming human population growth, human activity, and yes, even climate change, for the extinction of many large mammals.

A study recently published in the journal Proceedings of the National Academy of Science (PNAS) details how these findings were made.

According to the study, nearly six millennia ago there were 37 different species of large-bodied mammals plodding around Egypt - that's nearly five times today's grand total of only eight.

Many ancient species were recorded in artwork from the late Predynastic Period (before 3100 BC), but today they can no longer be found along the Nile.

According to first author Justin Yeakel, some of the disappeared mammals included lions, elephants, oryx, hartbeest, and even giraffe.

"As the number of species declined, one of the primary things that was lost was the ecological redundancy of the system," he added in a recent release. "There were multiple species of gazelles and other small herbivores, which are important because so many different predators prey on them. When there are fewer of those small herbivores, the loss of any one species has a much greater effect on the stability of the system and can lead to additional extinctions."

Using observational records of archeological and paleontological evidence compiled by zoologist Dale Osborne back in the late 1990s, Yeakel and his colleagues determined that five instances of dramatic change occurred within the Nile Valley's mammalian community in the last 6,000 years.

They found that human population growth and periods of acidification in the valley were key factors contributing to the extinction of some species. The results also showed that as local ecosystems become less varied, a single species decline began to have a disproportionally large impact on the region as a whole.

"This may be just one example of a larger pattern," Yeakel added. "We see a lot of ecosystems today in which a change in one species produces a big shift in how the ecosystem functions, and that might be a modern phenomenon. We don't tend to think about what the system was like 10,000 years ago."