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This timeline of prehistory covers the time from the appearance of Homo sapiens approximately 315,000 years ago in Africa to the invention of writing, over 5,000 years ago, with the earliest records going back to 3,200 BC.
These timelines of world history detail recorded events since the creation of writing roughly 5000 years ago to the present day. For events from c. 3200 BC – c. 500 see: Timeline of ancient history; For events from c. 500 – c. 1499, see: Timeline of post-classical history; For events from c. 1500, see: Timelines of modern history
Earth formed in this manner about 4.54 billion years ago (with an uncertainty of 1%) [25] [26] [4] and was largely completed within 10–20 million years. [27] In June 2023, scientists reported evidence that the planet Earth may have formed in just three million years, much faster than the 10−100 million years thought earlier.
The oscillating tilt of Earth's poles will move the North African Monsoon far enough north to change the climate of the Sahara back into a tropical one such as it had 5,000–10,000 years ago. [22] [23] 17,000 [note 1]
West African sediments additionally record the African humid period, an interval between 16,000 and 6,000 years ago during which Africa was much wetter than now. That was caused by a strengthening of the African monsoon by changes in summer radiation, which resulted from long-term variations in the Earth's orbit around the Sun.
The table starts counting approximately 10,000 years before present, or around 8,000 BC, during the middle Greenlandian, about 1,700 years after the end of the Younger Dryas and 1,800 years before the 8.2-kiloyear event. From the beginning of the early modern period until the 20th century, world population has been characterized by a rapid growth.
World map in 5000 BC. The 5th millennium BC spanned the years (5000 BC - 4001 BC) (c. 7 ka to c. 6 ka), that is, inclusive of 5000 BC but exclusive of 4000 BC. It is impossible to precisely date events that happened around the time of this millennium and all dates mentioned here are estimates mostly based on geological and anthropological analysis.
The first known mass extinction was the Great Oxidation Event 2.4 billion years ago, which killed most of the planet's obligate anaerobes. Researchers have identified five other major extinction events in Earth's history, with estimated losses below: [ 11 ]