Eurasia is the combined continental landmass of Europe and Asia, with the term being a portmanteau of its two constituents. Located primarily in the Northern and Eastern Hemispheres, it is bordered by the Atlantic Ocean on the west, the Pacific Ocean to the east, the Arctic Ocean on the north, and by Africa, the Mediterranean Sea, the Pacific Ocean and the Indian Ocean to the south. The division between Europe and Asia as two different continents is a historical and cultural construct, with no clear physical separation between them; thus, in some parts of the world, Eurasia is recognized as the largest of five or six continents. Eurasia covers around , or around 36.2% of the Earth’s total land area. The landmass contains around 4.6 billion people, equating to approximately 65% of the human population. Humans first settled in Eurasia from Africa, between 60,000 and 125,000 years ago.