Ancient Humans in Eastern Africa Altered the Region’s Ecosystems

A Yale-led study published recently in the Science Advances journal reported that early evidence from artifacts show that ancient humans altered the ecosystem.

Based on archaeological studies of thick clusters of stone artifacts unearthed in eastern Africa, along the northern shores of Lake Malawi, earliest humans as far back as 92,000 years, had altered the environment after gaining mastery of fire. Combining archaeological evidence and paleoenvironmental data, researchers were able to gather conclusive proof that ancient humans in eastern Africa burned the region’s forests in order to replace them with woodlands.

Fire was used as means of preventing forests from resurging, which led to the creation of the sprawling bushland that exists in Africa today. The manipulation of the ecosystem suggests that the ancient ecosystem engineers were largely farmers and herders, and not hunter-gatherers.

How the Evidences were Preserved

According to David Wright of the University of Oslo, who led in the study of archaeological sites, climate driven changes allowed the preservation of millions of artifacts. Wright explained that when it rained, dirt and trees were washed away and rolled downhill with nothing to stop them from being buried in the environment.

In the last arid period, the increased amount in charcoal found preserved in the archaeological sites, plus the absence of forest, led researchers to the conclusion that there was ecological manipulation using fire. A method that is quite similar to what modern farmers are doing today.

Author of the study, Jessica Thompson, who is a Yale paleoanthropologist and an assistant professor of anthropology, said their study provided the earliest evidence of how humans from as early as the Late Pleistocene, had altered the ecosystems through the use of fire. Although Thompson said it was not clear why they took to burning the landscape, as it is also possible that the burning of the forest went beyond their control.