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Human 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.
Byju's is an education tutoring app that runs on a freemium model, [30] with free access to content limited for 15 days after the registration. [30] [31] It was launched in August 2015, [32] offering educational content for students from classes 4 to 12. [33]
The period since 1950 has brought "the most rapid transformation of the human relationship with the natural world in the history of humankind". [106] Through 2018, humans have reduced forest area by ~30% and grasslands/shrubs by ~68%, to make way for livestock grazing and crops for humans. [107]
The first eon in Earth's history, the Hadean, begins with the Earth's formation and is followed by the Archean eon at 3.8 Ga. [2]: 145 The oldest rocks found on Earth date to about 4.0 Ga, and the oldest detrital zircon crystals in rocks to about 4.4 Ga, [34] [35] [36] soon after the formation of the Earth's crust and the Earth itself.
Human activities affect marine life and marine habitats through overfishing, habitat loss, the introduction of invasive species, ocean pollution, ocean acidification and ocean warming. These impact marine ecosystems and food webs and may result in consequences as yet unrecognised for the biodiversity and continuation of marine life forms. [3]
The consumption of polluted water leads to many deaths. In the year 2015, 1.8 million people world wide died because of water pollution and over 1 billion people became ill. [8] Low-income and third-world communities are especially endangered, because they often live close to industries with high emission. [8]
Annual world population growth peaked at 2.1% in 1968 and has since dropped to 1.1%. [1] According to the most recent United Nations' projections , the global human population is expected to reach 9.7 billion in 2050 and would peak at around 10.4 billion people in the 2080s, before decreasing, noting that fertility rates are falling worldwide.
Studies show that the pre-modern migration of human populations begins with the movement of Homo erectus out of Africa across Eurasia about 1.75 million years ago. Homo sapiens appeared to have occupied all of Africa about 150,000 years ago; some members of this species moved out of Africa 70,000 years ago (or, according to more recent studies, as early as 125,000 years ago into Asia, [1] [2 ...