Human

**Humans** (*Homo sapiens*) are the most abundant and widespread species of primate on Earth, characterized by bipedalism and large, complex brains. This has enabled the development of advanced tools, culture, and language. Humans are highly social 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 and to explain and manipulate phenomena have motivated humanity's development of science, philosophy, mythology, religion, and other fields of study.

Although some scientists equate the term *humans* with all members of the genus *Homo*, in common usage it generally refers to *Homo sapiens*, the only extant member. Anatomically modern Humans emerged around 300,000 years ago in Africa, evolving from *Homo heidelbergensis* or a similar species and migrating out of Africa, gradually replacing local populations of archaic Humans. For most of history, all Humans were nomadic hunter-gatherers. Humans began exhibiting behavioral modernity about 160,000-60,000 years ago. The Neolithic Revolution, which began in Southwest Asia around 13,000 years ago (and separately in a few other places), saw the emergence of agriculture and permanent human settlement. As populations became larger and denser, forms of governance developed within and between communities and a number of civilizations have risen and fallen. Humans have continued to expand, with a global population of over 7.9 billion as of 2022.

Genes and the environment influence human biological variation in visible characteristics, physiology, disease susceptibility, mental abilities, body size and life span. Though humans vary in many traits (such as genetic predispositions and physical features), any two humans are at least 99% genetically similar. Humans are sexually dimorphic: generally, men have greater body strength and women have a higher body fat percentage. At puberty, humans develop secondary sex characteristics. Women are capable of pregnancy, and undergo menopause and become infertile at around the age of 50.

Humans are omnivorous, capable of consuming a wide variety of plant and animal material, and have used fire and other forms of heat to prepare and cook food since the time of *H. 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. Often, both the mother and the father provide care for their children, who are helpless at birth.

Humans have a large and highly developed prefrontal cortex, the region of the brain associated with higher cognition. They are intelligent, capable of episodic memory, have flexible facial expressions, self-awareness and a theory of mind. The human mind is capable of introspection, private thought, imagination, volition and forming views on existence. This has allowed great technological advancements and complex tool development possible through reason and the transmission of knowledge to subsequent generations. Language, art and trade are defining characteristics of Humans. Long-distance trade routes might have led to cultural explosions and resource distribution that gave humans an advantage over other similar species.

## History

### Origin

Anatomically modern Humans emerged around 300,000 years ago in Africa, evolving from *Homo heidelbergensis* or a similar species and migrating out of Africa, gradually replacing local populations of archaic Humans.

### 12,000 Years Ago

Until about 12,000 years ago, all humans lived as hunter-gatherers. The Neolithic Revolution (the invention of agriculture) first took place in Southwest Asia and spread through large parts of the Old World over the following millennia. It also occurred independently in Mesoamerica (about 6,000 years ago), China, Papua New Guinea, and the Sahel and West Savanna regions of Africa. Access to food surplus led to the formation of permanent human settlements, the domestication of animals and the use of metal tools for the first time in history. Agriculture and sedentary lifestyle led to the emergence of early civilizations.

An urban revolution took place in the 4th millennium BCE with the development of city-states, particularly Sumerian cities located in Mesopotamia. It was in these cities that the earliest known form of writing, cuneiform script, appeared around 3000 BCE. Other major civilizations to develop around this time were Ancient Egypt and the Indus Valley Civilization. They eventually traded with each other and invented technology such as wheels, plows and sails. Astronomy and mathematics were also developed and the Great Pyramid of Giza was built. There is evidence of a severe drought lasting about a hundred years that may have caused the decline of these civilizations, with new ones appearing in the aftermath. Babylonians came to dominate Mesopotamia while others, such as Poverty Point cultures, Minoans and the Shang dynasty, rose to prominence in new areas. The Bronze Age suddenly collapsed around 1200 BCE, resulting in the disappearance of a number of civilizations and the beginning of the Greek Dark Ages. During this period iron started replacing bronze, leading to the Iron Age.

In the 5th century BCE, history started being recorded as a discipline, which provided a much clearer picture of life at the time. Between the 8th and 6th century BCE, Europe entered the classical antiquity age, a period when ancient Greece and ancient Rome flourished. Around this time other civilizations also came to prominence. The Maya civilization started to build cities and create complex calendars. In Africa, the Kingdom of Aksum overtook the declining Kingdom of Kush and facilitated trade between India and the Mediterranean. In West Asia, the Achaemenid Empire's system of centralized governance became the precursor to many later empires, while the Gupta Empire in India and the Han dynasty in China have been described as golden ages in their respective regions.
Routes taken by barbarian invaders of the Roman Empire during the Migration Period
Following the fall of the Western Roman Empire in 476, Europe entered the Middle Ages. During this period, Christianity and the Church would provide centralized authority and education. In the Middle East, Islam became the prominent religion and expanded into North Africa. It led to an Islamic Golden Age, inspiring achievements in architecture, the revival of old advances in science and technology, and the formation of a distinct way of life. The Christian and Islamic worlds would eventually clash, with the Kingdom of England, the Kingdom of France and the Holy Roman Empire declaring a series of holy wars to regain control of the Holy Land from Muslims. In the Americas, complex Mississippian societies would arise starting around 800 CE, while further south, the Aztecs and Incas would become the dominant powers. The Mongol Empire would conquer much of Eurasia in the 13th and 14th centuries. Over this same time period, the Mali Empire in Africa grew to be the largest empire on the continent, stretching from Senegambia to Ivory Coast. Oceania would see the rise of the Tuʻi Tonga Empire which expanded across many islands in the South Pacific.

Throughout the early modern period (1500–1800), the Ottomans controlled the lands around the Mediterranean Basin, Japan entered the Edo period, the Qing dynasty rose in China and the Mughal Empire ruled much of India. Europe underwent the Renaissance, starting in the 15th century, and the Age of Discovery began with the exploring and colonizing of new regions. This includes the British Empire expanding to become the world's largest empire and the colonization of the Americas. This expansion led to the Atlantic slave trade and the genocide of Native American peoples. This period also marked the Scientific Revolution, with great advances in mathematics, mechanics, astronomy and physiology.

The late modern period (1800–present) saw the Technological and Industrial Revolution bring such discoveries as imaging technology, major innovations in transport and energy development. The United States of America underwent great change, going from a small group of colonies to one of the global superpowers. The Napoleonic Wars raged through Europe in the early 1800s, Spain lost most of its New World colonies and Europeans continued expansion into Oceania and Africa (where European control went from 10% to almost 90% in less than 50 years). A tenuous balance of power among European nations collapsed in 1914 with the outbreak of the First World War, one of the deadliest conflicts in history. In the 1930s, a worldwide economic crisis led to the rise of authoritarian regimes and a Second World War, involving almost all the world's countries. Following its conclusion in 1945, the Cold War between the USSR and the United States saw a struggle for global influence, including a nuclear arms race and a space race. The current Information Age sees the world becoming increasingly globalized and interconnected.