Human history

Human history or world history is the record of humankind from prehistory to the present. Modern humans evolved in Africa around 300,000 years ago and initially lived as hunter-gatherers. They migrated out of Africa during the Last Ice Age and had spread across Earth's continental land except Antarctica by the end of the Ice Age 12,000 years ago. Soon afterward, the Neolithic Revolution in West Asia brought the first systematic husbandry of plants and animals, and saw many humans transition from a nomadic life to a sedentary existence as farmers in permanent settlements. The growing complexity of human societies necessitated systems of accounting and writing.

These developments paved the way for the emergence of early civilizations in Mesopotamia, Egypt, the Indus Valley, and China, marking the beginning of the ancient period in 3500 BCE. These civilizations supported the establishment of regional empires and acted as a fertile ground for the advent of transformative philosophical and religious ideas, initially Hinduism during the late Bronze Age, and – during the Axial Age: Buddhism, Confucianism, Greek philosophy, Jainism, Judaism, Taoism, and Zoroastrianism. The subsequent post-classical period, from about 500 to 1500 CE, witnessed the rise of Islam and the continued spread and consolidation of Christianity while civilization expanded to new parts of the world and trade between societies increased. These developments were accompanied by the rise and decline of major empires, such as the Byzantine Empire, the Islamic caliphates, the Mongol Empire, and various Chinese dynasties. This period's invention of gunpowder and of the printing press greatly affected subsequent history.

During the early modern period, spanning from approximately 1500 to 1800 CE, European powers explored and colonized regions worldwide, intensifying cultural and economic exchange. This era saw substantial intellectual, cultural, and technological advances in Europe driven by the Renaissance, the Reformation in Germany giving rise to Protestantism, the Scientific Revolution, and the Enlightenment. By the 18th century, the accumulation of knowledge and technology had reached a critical mass that brought about the Industrial Revolution, substantial to the Great Divergence, and began the modern period starting around 1800 CE. The rapid growth in productive power further increased international trade and colonization, linking the different civilizations in the process of globalization, and cemented European dominance throughout the 19th century. Over the last 250 years, which included two devastating world wars, there has been a great acceleration in many spheres, including human population, agriculture, industry, commerce, scientific knowledge, technology, communications, military capabilities, and environmental degradation.

The study of human history relies on insights from academic disciplines including history, archaeology, anthropology, linguistics, and genetics. To provide an accessible overview, researchers divide human history by a variety of periodizations.

Humans evolved in Africa from great apes through the lineage of hominins, which arose 7–5 million years ago. The ability to walk on two legs emerged in early hominins after the split from chimpanzees, as an adaptation possibly associated with a shift from forest to savanna habitats. Hominins began to use rudimentary stone tools c. 3.3 million years ago, marking the advent of the Paleolithic era.

The genus Homo evolved from Australopithecus. The earliest record of Homo is the 2.8 million-year-old specimen LD 350-1 from Ethiopia, and the earliest named species is Homo habilis which evolved by 2.3 million years ago. The most important difference between Homo habilis and Australopithecus was a 50% increase in brain size. H. erectus evolved about 2 million years ago and was the first hominin species to leave Africa and disperse across Eurasia. Perhaps as early as 1.5 million years ago, but certainly by 250,000 years ago, hominins began to use fire for heat and cooking.

Beginning about 500,000 years ago, Homo diversified into many new species of archaic humans such as the Neanderthals in Europe, the Denisovans in Siberia, and the diminutive H. floresiensis in Indonesia. Human evolution was not a simple linear or branched progression but involved interbreeding between related species. Genomic research has shown that hybridization between substantially diverged lineages was common in human evolution. DNA evidence suggests that several genes of Neanderthal origin are present among all non-sub-Saharan African populations. Neanderthals and other hominins, such as Denisovans, may have contributed up to 6% of their genome to present-day non-sub-Saharan African humans.

Homo sapiens emerged in Africa around 300,000 years ago from the species Homo heidelbergensis. Humans continued to develop over the succeeding millennia, and by 100,000 years ago, were using jewelry and ocher to adorn the body. By 50,000 years ago, they buried their dead, used projectile weapons, and engaged in seafaring. One of the most important changes (the date of which is unknown) was the development of syntactic language, which dramatically improved the human ability to communicate. Signs of early artistic expression can be found in the form of cave paintings and sculptures made from ivory, stone, and bone, implying a form of spirituality generally interpreted as animism or shamanism. The earliest known musical instruments besides the human voice are bone flutes from the Swabian Jura in Germany, dated around 40,000 years old. Paleolithic humans lived as hunter-gatherers and were generally nomadic.