As descendants of Homo habilis, Homo erectus appeared on the historical stage of human evolution in Africa about 2 million years ago.
Homo erectus
The brains of Homo erectus were significantly larger, with early members having a brain volume of around 800 ml and later members around 1200 ml. Moreover, the brains not only increased in size, but their structure also became more complex and reorganized, indicating that Homo erectus had developed fairly complex cultural behaviors. The asymmetry between the left and right hemispheres of the brain suggests that Homo erectus had already mastered spoken language.
The teeth of Homo erectus also underwent changes. The posterior teeth decreased in size, which should have resulted in a reduction in the corresponding jawbone and the bone structure supporting the face and mandible. This is clearly related to the fact that Homo erectus consumed more meat and more frequently than some plant-based foods. The anterior teeth enlarged, which does not seem to be directly related to chewing food, but rather to biting and holding objects in the mouth. It may also be related to the preparation of animal foods, such as tearing meat with teeth to cut it into smaller pieces, or tearing meat into smaller pieces for children to eat.
Acheulean handaxe
Homo erectus had a relatively flat face and a significantly larger body, averaging 160 cm in height and about 60 kg in weight. Homo erectus was the first human species to use fire; they were also the first to be able to manufacture stone tools according to a preconceived pattern. In Africa, this type of stone tool assembly represents a cultural type known as the Acheulean culture, named after the Saint-Acheule site in northern France where similar stone tool cultures have also been discovered. The representative tool of the Acheulean culture was the hand axe, made from flint nodules, with one blunt end for gripping and the other sharp end for cutting, chopping, drilling, and processing wood.
The emergence of Homo erectus marked another significant shift in human prehistory two million years ago. A series of progressive features greatly expanded their adaptability. Therefore, unlike their predecessors who merely roamed the African plains, Homo erectus later ventured out of Africa, spreading across vast areas of Asia and much of Europe.
