Human

Humans (Homo sapiens, meaning 'thinking man' or 'wise man') are the most abundant and widespread species of primates, characterized by bipedality, hairlessness, and large, complex brains enabling the development of advanced technology, culture, and language. Humans are highly social beings and tend to live in complex social structures composed of many cooperating and competing groups, from families and kinship networks to political states. Social interactions between humans have established a wide variety of values, social norms, and rituals, which bolster human society. Curiosity and the human desire to understand and influence the environment have motivated humanity's development of science, philosophy, religion, mythology and other fields of knowledge. Humans have a large and highly developed prefrontal cortex, the region of the brain associated with higher cognition. They are intelligent beings, capable of episodic memory, flexible facial expressions, self-awareness and a theory of mind. The human mind is capable of introspection (meta-cognition), private thought, imagination, volition and forming views on existence. Humans can also mentally travel through time (chronesthesia) which signifies episodic foresight. These attributes have allowed great technological advancements through reason and the transmission of knowledge to future generations. In cultural anthropology, the cumulative preservation and advancement of knowledge across generations is known as the Ratchet Effect. Humans are omnivorous, capable of consuming a wide variety of plant and animal material, and have used fire to prepare and cook food since the time of Homo erectus. They can survive for up to eight weeks without food, and three or four days without water. Humans are generally diurnal, sleeping on average seven to nine hours per day. Childbirth is dangerous, with a high risk of complications and death. Both the mother and the father typically provide care for human offspring who are helpless at birth. Genes and the environment influence human biological variation in appearance, physiology, immune system, mental abilities, body size and lifespan. Though humans vary in many traits, any two humans are on average over 99% genetically similar, with the most genetically diverse populations from Africa. The greatest degree of genetic variation exists between males and females. On average, males have greater body strength and females generally have a higher body fat percentage. Females undergo menopause and become infertile potentially decades before the end of their lives. They also have a longer life span in almost every population around the world. The division into male and female gender roles has varied historically, and challenges to predominant gender norms have recurred in many societies. Humans evolved from other hominins in Africa several million years ago. Although some scientists equate humans with all members of the genus Homo, in common usage it generally refers to Homo sapiens, the only extant member. Homo sapiens emerged around 300,000 years ago and migrated out of Africa, gradually replacing local populations of archaic humans. Early humans were hunter-gatherers, before the invention of agriculture and domestication of animals led to permanent settlement in the Fertile Crescent and other cradles of civilization. As food surpluses enabled populations to become larger and denser, forms of governance developed, the use of writing became necessary, and a number of civilizations rose and fell. Humans have continued to expand, with over 8 billion humans occupying almost all regions of Earth in 2026. Moreover, humans have visited the Moon and sent human-made spacecraft to other celestial bodies, becoming the first known species to do so.