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  2. Timeline of human evolution - Wikipedia

    en.wikipedia.org/wiki/Timeline_of_human_evolution

    [47] [48] Brain expansion (enlargement) between 0.8 and 0.2 Ma may have occurred due to the extinction of most African megafauna (which made humans feed from smaller prey and plants, which required greater intelligence due to greater speed of the former and uncertainty about whether the latter were poisonous or not), extreme climate variability ...

  3. Timeline of the evolutionary history of life - Wikipedia

    en.wikipedia.org/wiki/Timeline_of_the...

    At long irregular intervals, Earth's biosphere suffers a catastrophic die-off, a mass extinction, [9] often comprising an accumulation of smaller extinction events over a relatively brief period. [10] The first known mass extinction was the Great Oxidation Event 2.4 billion years ago, which killed most of the planet's obligate anaerobes.

  4. History of life - Wikipedia

    en.wikipedia.org/wiki/History_of_life

    The history of life on Earth traces the processes by which living and extinct organisms evolved, from the earliest emergence of life to the present day. Earth formed about 4.5 billion years ago (abbreviated as Ga, for gigaannum) and evidence suggests that life emerged prior to 3.7 Ga. [1] [2] [3] The similarities among all known present-day species indicate that they have diverged through the ...

  5. Human extinction - Wikipedia

    en.wikipedia.org/wiki/Human_extinction

    Nuclear war is an often-predicted cause of the extinction of humankind. [1]Human extinction or omnicide is the hypothetical end of the human species, either by population decline due to extraneous natural causes, such as an asteroid impact or large-scale volcanism, or via anthropogenic destruction (self-extinction), for example by sub-replacement fertility.

  6. Evolution - Wikipedia

    en.wikipedia.org/wiki/Evolution

    Present-day extinction rates are 100–1000 times greater than the background rate and up to 30% of current species may be extinct by the mid 21st century. [230] Human activities are now the primary cause of the ongoing extinction event; [231] [232] global warming may further accelerate it in the future. [233]

  7. List of extinction events - Wikipedia

    en.wikipedia.org/wiki/List_of_extinction_events

    Extinction Date Probable causes [2] Quaternary: Holocene extinction: c. 10,000 BC – Ongoing: Humans [3] Quaternary extinction event: 640,000, 74,000, and 13,000 years ago: Unknown; may include climate changes, massive volcanic eruptions and Humans (largely by human overhunting) [4] [5] [6] Neogene: Pliocene–Pleistocene boundary extinction: 2 Ma

  8. Human history - Wikipedia

    en.wikipedia.org/wiki/Human_history

    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.

  9. Human evolution - Wikipedia

    en.wikipedia.org/wiki/Human_evolution

    A number of other changes have also characterized the evolution of humans, among them an increased reliance on vision rather than smell (highly reduced olfactory bulb); a longer juvenile developmental period and higher infant dependency; [181] a smaller gut and small, misaligned teeth; faster basal metabolism; [182] loss of body hair; [183] an ...