The history of the world is vast and complex, spanning millions of years. Below is a summarized timeline that highlights major events and developments in the history of humanity and the planet: Prehistoric Era (Before 3000 BCE) Origin of Life: Life on Earth began over 3.5 billion years ago with single-celled organisms in the oceans. Hominid Evolution: Humans (Homo sapiens) evolved from primate ancestors. Early hominids like Australopithecus appeared around 4 million years ago, and Homo habilis and Homo erectus emerged around 2.5 million and 1.9 million years ago, respectively.