Search results
Results From The WOW.Com Content Network
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.
The timeline of human evolution outlines the major events in the evolutionary lineage of the modern human species, Homo sapiens, throughout the history of life, beginning some 4 billion years ago down to recent evolution within H. sapiens during and since the Last Glacial Period.
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 ...
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.
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
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 ...
A 2022 Outside article on heat stroke cites the highest known body temperature that a human was able to survive: “The highest body temperature measured was only 17 degrees above normal. Willie ...
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]