Early humans began migrating out of Africa starting around 1 million years ago. The earliest humans included Australopithecus, Homo habilis, Homo erectus, and Homo sapiens. Around 8,000 BCE, humans began transitioning from nomadic hunter-gatherer bands to more settled agricultural villages as part of the Neolithic Revolution. This led to improved living conditions, growing populations, and the development of early civilizations in Mesopotamia, Egypt, the Indus Valley, and others by around 6000 BCE.