Up until now, scientists believed the tsetse fly was what stopped African herders from further migrating south of the Saharan desert but recent enamel studies show the tsetse fly did not influence African history.
The Sahara desert started to expand 5,500 years ago which meant herders needed to migrate towards the south in search of better environments for cattle raising. The migration apparently stopped 2,000 years ago. Up until now, the theory was that this winged disease-carrying creature was the obstacle that intervened in the process of moving south. Scientists believed both cattle and their herders had fallen victims of the illnesses caused by this fly: sleeping sickness and nagana.
This theory is, however, wrong. According to the new study which was conducted on teeth belonging to 2000-year-old ancient animals (domestic and wild herbivores) from the Kenya Gogo Falls settlement there is another explanation.
Fiona Marshall, study co-author and professor of anthropology at Washington University in St. Louis explains how “the vegetation east of Lake Victoria was then much different than it is today”. She continued by saying that “ancient grassy environments may have provided an important corridor for herders moving into southern Africa.”
The tooth enamel analysis revealed that the animals were grazing on lush vegetation meaning there was a low probability for the tsetse fly to be present in such areas. As the animals and their herders were living on fertile land, eating from both domestic and wild food sources was an option, not a necessity.
Marshall considers that the study will “challenge existing models that explain the settlement’s diverse diet as a consequence of depressed livestock production related to tsetse flies”. This research brings forward a new theory according to which “herders may simply have interacted with hunter-gatherer groups already living in these areas, adapting to their foraging styles”. This means social interactions might have had a greater influence on the development of pastoralism in Eastern Africa than initially believed.
One of the changes that took place due to pastoral migrations was a mutation which allowed humans to drink milk of animal origin. Up until then, humans were able to drink only human milk.
This new study sheds new light upon various factors that contributed to the modern distribution of human and animal populations.
Image Source: IPS