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The atmosphere present from this point in Earth's history until the origin of life is referred to as the prebiotic atmosphere. It is unknown when exactly life originated. The oldest direct evidence for life on Earth is around 3.5 billion years old, such as fossil stromatolites from North Pole, Western Australia. [14]
A biosphere based on ammonia would likely exist at temperatures or air pressures that are extremely unusual in relation to life on Earth. Life on Earth usually exists between the melting point and boiling point of water, at a pressure designated as normal pressure, between 0 and 100 °C (273 and 373 K). When also held to normal pressure ...
Pneuma (πνεῦμα) is an ancient Greek word for "breath", and in a religious context for "spirit". [1] [2] It has various technical meanings for medical writers and philosophers of classical antiquity, particularly in regard to physiology, and is also used in Greek translations of ruach רוח in the Hebrew Bible, and in the Greek New Testament.
Altogether, these three developments in science presented the wider scientific community with a seemingly paradoxical situation regarding the origin of life: life must have evolved from non-biological precursors after the Earth was formed, and yet spontaneous generation as a theory had been experimentally disproved.
Cyanobacteria dramatically changed the composition of life forms on Earth by leading to the near-extinction of oxygen-intolerant organisms. The diversity of life on Earth is a result of the dynamic interplay between genetic opportunity, metabolic capability, environmental challenges, [95] and symbiosis.
Sir David Attenborough has teased a scene in the new Planet Earth that made him hold his breath.
The composition of Earth's atmosphere is determined by the by-products of the life that it sustains. Dry air (mixture of gases) from Earth's atmosphere contains 78.08% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and traces of hydrogen, helium, and other "noble" gases (by volume), but generally a variable amount of water vapor is ...
NEW HAVEN, Conn. (AP) - "I can't breathe!" - the exclamation made by a black man, Eric Garner, while being placed in a police chokehold - was chosen as the most notable quote of the year in an ...