Human Evolution: From Homo Erectus to Homo Sapiens
Homo Erectus
The Homo erectus skull was flattened and lacked a chin. Its cranial capacity increased to 900 cm3. Homo erectus fossils range from 1.5 million to 300,000 years old. They made instruments characterized by the cutting of stone according to function. Their social organization was based on hunting, cooperation, and division of tasks. This Homo species mastered fire and used it for cooking and defense. They communicated through a sound system and, despite their lack of advanced intelligence, were able to understand associations like “if A, then B.”
Homo Neanderthal
Homo neanderthalensis exhibited a large face with a receding forehead, a prominent jaw, and a receding chin. Its cranial capacity reached up to 1,600 cm3. They used wood and metals in the manufacture of their furniture. They continued to use fire for cooking and defense and also used it inside caves for warmth. Homo neanderthalensis buried their dead, performed funeral rites, and practiced religious rituals.
Homo Sapiens
Homo sapiens have a flat face, a developed forehead, and a defined chin. Their cranial capacity exceeds 1,500 cm3. They made instruments out of wood and metal, similar to Neanderthals, as well as tools for agriculture and hunting. Their social organization began as nomadic (gathering and hunting) and, after the Neolithic revolution, became sedentary (agriculture). They used fire in the same way as Neanderthals and also for forging metal. Like Neanderthals, Homo sapiens also venerated their dead. As for communication, they had a sign language. Homo sapiens have self-awareness, and community members discover their own value as individuals. In art, Homo sapiens are responsible for cave paintings.
Human Evolution Studies
The study of human beings differs in three branches:
- Phylogeny: Studies the human at the species level, focusing on specific anatomical and behavioral characteristics.
- Anthropogenesis: Investigates the conditions under which humans are a special case within the animal kingdom, considering their learning, determination, and responsibility.
- Sociogenesis: Studies human behavior in a social context. Social interactions affect their intelligence, behavior, and sensitivity.
Hominization Process: Differences from Animal Ancestors
The human species evolved from hominids who underwent a series of changes that differentiated them from other primates. This set of changes, called the hominization process, occurred at three levels:
Anatomical Changes
- Bipedalism and upright posture: Feet became wider and lost their prehensile function. The field of vision increased, enhancing adaptability to the environment.
- Release of the hand: Due to the upright position, the hand developed to make increasingly complex and precise movements (toolmaking).
- Facial changes: The face of hominids changed due to these developments.
- Increased cranial capacity: Brain size increased, which explains human intelligence and their capabilities for signs, culture, art, etc. Within the biological plot, anatomical changes are the most important because genetic and biochemical differences from primates are scarce.
Physiological Changes
- Orthogenia: Slow individual development.
- Neoteny: Continuing need for learning.
Psychosocial Changes
- Need for mutual aid (social).
- Accumulation of knowledge shared with the rest of the group.
- Emergence of language (from cries to words).