The Mosaic of Evolution: Bipedalism and African Tectonics

The article criticizes linear concepts of bipedalism evolution, opposing them with a mosaic model. The author analyzes the transition from arboreal locomotion to habitual bipedal walking, pointing to early forms such as Sahelanthropus tchadensis, which combined both traits. The text questions the simplified savanna hypothesis, suggesting that bipedalism was not a sudden effect of Africa's drying, but a long-term adaptive process. A significant role is attributed to the East African Rift System, however, not as a rigid biogeographic barrier, but as a generator of environmental heterogeneity. Africa's geology created diverse boundary conditions that forced adaptive flexibility in hominins, making the fossil record in this region exceptionally rich, although potentially overrepresented in the current picture of evolution.