Ancient Tooth Enamel Reveals that Tsetse Flies Didn't Impact the Migration Route of Herders

Scientists are learning a bit more about herders from northern Africa that lived nearly 2,000 years ago by examining ancient teeth. The researchers have found that early herders may have traveled past Kenya's Lake Victoria on their way to southern Africa because the area was grassy--not tsetse fly--infested bushland, as previously believed.

"We studied the chemical signature of teeth in wild antelopes and domestic plant-eating animals-cows and sheep or goats-and found they all were eating a lot of grass in the Lake Victoria basin," said Kendra Chritz, first author of the new study, in a news release. "That means Lake Victoria could have been an area through which people passed while migrating southward to southern Africa."

Scientists have long wondered which route ancient populations took when migrating southward. Recent genetic evidence has supported the idea that people moved from east Africa to southern Africa about 2,000 years ago, but the path they took has long been debated. Not only that, but Lake Victoria was long thought to not be part of the route because of a natural barrier-a cool, moist, bushy environment filled with tsetse flies.

It turns out, though, that Lake Victoria wasn't as much as a barrier as previously thought. In this latest study, the scientists examined fossil teeth of various animals that had been collected at a site on the east side of Lake Victoria known as Gogo falls.

The people that traveled through Kenya were known as Elmenteitan herders. The Elementeitan herders at GogoFalls, though, have long puzzled researchers. They only relied about 50 percent on domestic animals and the rest on hunting and fishing.

"The assumption was that due to some sort of environmental constraint, they weren't able to maintain large herds of domestic animals," said Chritz. "The specific assumption relates to the presence of the tsetse fly, which carries African sleeping sickness or trypanosomiasis. This is fatal to cattle, goats, sheep and people. It's very difficult to maintain livestock where there are abundant tsetse flies."

And yet it seems that this wasn't the case. After examining the teeth, the researchers found that the animals ate a grassy diet rather than a bushy diet. This, in turn, indicates that the environment around Gogo Falls and Lake Victoria consisted of a grassy landscape that may have attracted herders rather than repelled them.

The findings reveal that Lake Victoria wasn't a natural barrier. Instead, it's possible that Lake Victoria may have been an area through which people passed while migrating southward. This, in turn, reveals a bit more about the southward migration of these herders.

The findings are published in the journal Proceedings of the National Academy of Sciences.

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