The origins of the savannah

Before the last glaciations, the Earth certainly looked very different from the way it looks today. In the past, the areas where there are deserts and savannahs now were covered with forests, while an expanse of ice covered the medium and high altitudes. As the climate got drier, the forests slowly disappeared and the savannahs got in.
In particular, geological events occurred in the African forests, approximately 7 or 8 million years ago, which can now be explained by plate tectonics and which caused savannahs and man to appear on Earth.
The rift valley, that later on would cause the Horn of Africa (Eritrea, Ethiopia, Uganda, etc.) to come off the continent, began to form. This area, that extends north to south along the Great Lake line, was tormented for a long time by an intense volcanic activity, which brought along significant climatic changes. The west winds, loaded with rain, no longer reached the inland, which as a consequence dried up. The forest thus disappeared and was replaced by the savannah, a new environment, unsuitable for the tree monkeys and favourable therefore to those species that began abler to use their back limbs, thus getting on their way to walk on two legs. Conversely, the bigger monkeys kept evolving as the forests retreated. In the grassy areas, to walk upright was useful to explore the environment and quickly locate dangers. New forms of life, better suited to living outdoors, began to appear, goaded by the new life style, and originated the evolutionary line of the hominids. In addition to these geological events, the savannah has been developed in more recent times by man, who cut trees for timber, put lands to pasture and burnt down the forests. Man’s action has actually extended what was the natural area of this biome and still keeps it like it.

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