American scientists described a long period of landscape instability in the East African Rift Valley and found out what reasons could have prompted our ancestors to start rapid development - to complicate tools and exchange them with neighbors.
The research is published in the journal Science Advances. Landscape and climate changes have always been perceived by many scientists as factors responsible for the evolution of living things, including human culture. So, experts believe that due to the disappearance of tropical forests and the emergence of savannas (in the process of cooling the climate), our ancestors got off the trees and got to their feet.
The current study by scientists from the Smithsonian National Museum of Natural History described a long period of landscape instability in the East African Rift Valley, which began about 400 thousand years ago due to tectonic activity.
It formed small lakes along the fault lines, thus shattering the grassy plains of East Africa, making these bodies of water more sensitive to changes in precipitation than the larger lakes in the region before.
The general elevation of the area also contributed to the drying up of shallow water bodies. This has led to frequent and dramatic fluctuations in the water supply. As a result, the vegetation of the East African Plain also changed, and with it the fauna: herbivores died out, their place was taken by smaller mammals with a more varied diet.
It was during this period, as shown by early studies of the same group of paleoanthropologists (published in 2018), that the cultural aspects of the activities of our ancestors changed: they began to exchange tools between groups, began to produce more sophisticated and elegant tools and use coloring pigments, which suggests the emergence of symbolism. The Acheulean culture gave way to the Middle Stone Age. Such changes, according to scientists, took place about 320 thousand years ago.