Evolution: Does oxygen level hold the key (Evolution)
Evolution was slow or non-existent for a billion years early on:, with very low oxygen levels:-https://www.sciencenews.org/article/new-fascination-earths-boring-billion-"Earth's long history starts with an epic preamble: A collision with a Mars-sized space rock rips into the young planet and jettisons debris that forms the moon. Over the next few billion years, plot twists abound. The oceans form. Life appears. Solar-powered microbes breathe oxygen into the air. Colossal environmental shifts reshape the planet's surface and drive the evolution of early life.-"After this wild youth of rapid change, things slowed down. About 1.8 billion years ago, the climate stabilized. Oxygen levels steadied. Evolution seemingly stalled. For around a billion years, not a lot changed on planet Earth. Scientists called this interval the dullest time in Earth's history. It came to be known as the “boring billion.”-***- "The planet's first whiff of oxygen came more than 3.2 billion years ago, following the evolution of the earliest photosynthetic microbes, cyanobacteria (SN Online: 9/8/15). These bacteria churn out oxygen into the environment. When the microscopic critters die, however, their remains decay and consume oxygen. Normally the life and death of a cyanobacterium would result in no net oxygen gain. Luckily for oxygen-loving life, accumulating sediments can bury the decaying organic matter under the seafloor and halt the drawdown of oxygen.-"Before the boring billion, around 2.4 billion to 2.3 billion years ago, cyanobacteria flooded Earth's atmosphere with oxygen (SN: 10/10/09, p. 11). This oxygen rise, nicknamed the Great Oxidation Event, permanently altered the planet's chemical portfolio and purged the surface of nearly all oxygen-intolerant life.-"The breath of oxygen ultimately spurred the evolution of complex life-forms called eukaryotes, with distinct cell nuclei and organelles. Early eukaryotes — the forebears of animals and plants — appeared at the start of the boring billion, 1.8 billion years ago. During their first few hundred million years, single- and multicelled eukaryotes eked out a marginal existence while bacteria and archaea unequivocally ruled Earth's ecosystem."-Comment: no question oxygen is needed for today's complex animals, but much more than oxygen is required to advance evolution.
Complete thread:
- Evolution -
dhw,
2008-03-22, 11:02
- Evolution - George Jelliss, 2008-03-22, 16:52
- Evolution -
David Turell,
2008-03-22, 17:12
- Evolution -
George Jelliss,
2008-03-23, 12:26
- Evolution -
David Turell,
2008-03-23, 16:17
- Evolution -
dhw,
2008-03-24, 07:50
- Evolution - David Turell, 2008-03-24, 15:24
- Evolution -
George Jelliss,
2008-03-26, 13:10
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David Turell,
2015-10-28, 00:19
- Evolution; chicken mutation rates -
dhw,
2015-10-28, 11:54
- Evolution; chicken mutation rates - David Turell, 2015-10-28, 17:06
- Evolution; chicken mutation rates -
dhw,
2015-10-28, 11:54
- Evolution -
dhw,
2008-03-24, 07:50
- Evolution -
David Turell,
2008-03-23, 16:17
- Evolution -
George Jelliss,
2008-03-23, 12:26
- Evolution - Kyuuketsuki, 2008-03-25, 20:58
- Evolution joke -
Cary Cook,
2008-05-26, 00:27
- Evolution joke -
Neil,
2008-05-26, 17:14
- Evolution joke - David Turell, 2008-05-26, 17:24
- Evolution joke - Cary Cook, 2008-05-27, 00:25
- Evolution joke -
Neil,
2008-05-26, 17:14
- Evolution -
David Turell,
2008-11-09, 16:04
- Evolution -
Carl,
2008-11-10, 16:15
- Evolution -
David Turell,
2008-11-10, 18:56
- Evolution -
David Turell,
2009-01-11, 14:35
- Evolution -
George Jelliss,
2009-01-11, 16:31
- Evolution -
David Turell,
2009-01-11, 17:03
- Evolution -
dhw,
2009-01-13, 17:57
- Evolution - David Turell, 2009-01-14, 00:01
- Evolution - David Turell, 2009-01-14, 02:29
- Evolution -
George Jelliss,
2009-01-15, 09:18
- Evolution - David Turell, 2009-01-16, 00:44
- Evolution -
dhw,
2009-01-16, 13:08
- Evolution -
George Jelliss,
2009-01-19, 10:36
- Evolution -
David Turell,
2009-01-19, 14:34
- Evolution -
David Turell,
2009-01-19, 16:32
- Evolution -
George Jelliss,
2009-01-20, 10:20
- Evolution - David Turell, 2009-01-20, 14:11
- Evolution - David Turell, 2009-01-21, 14:11
- Evolution -
David Turell,
2009-01-24, 17:14
- Evolution -
David Turell,
2009-01-26, 13:54
- Evolution -
George Jelliss,
2009-01-27, 10:11
- Evolution -
David Turell,
2009-01-27, 14:29
- Evolution -
David Turell,
2009-01-28, 14:41
- Evolution -
David Turell,
2009-01-28, 16:56
- Evolution -
David Turell,
2009-01-30, 13:53
- Evolution -
David Turell,
2009-01-31, 16:42
- Evolution -
dhw,
2009-02-04, 13:49
- Evolution -
David Turell,
2009-02-04, 17:46
- Evolution -
David Turell,
2009-02-05, 01:24
- Evolution - David Turell, 2009-02-05, 05:20
- Evolution -
David Turell,
2009-02-08, 16:03
- Evolution - George Jelliss, 2009-02-08, 19:36
- Evolution -
David Turell,
2009-02-25, 01:00
- Evolution - David Turell, 2009-06-10, 14:32
- Evolution -
David Turell,
2009-02-05, 01:24
- Evolution -
David Turell,
2009-02-04, 17:46
- Evolution -
dhw,
2009-02-04, 13:49
- Evolution -
David Turell,
2009-01-31, 16:42
- Evolution -
David Turell,
2009-01-30, 13:53
- Evolution -
David Turell,
2009-01-28, 16:56
- Evolution -
David Turell,
2009-01-28, 14:41
- Evolution -
David Turell,
2009-01-27, 14:29
- Evolution -
George Jelliss,
2009-01-27, 10:11
- Evolution -
David Turell,
2009-01-26, 13:54
- Evolution -
George Jelliss,
2009-01-20, 10:20
- Evolution -
David Turell,
2009-01-19, 16:32
- Evolution - dhw, 2009-01-21, 15:28
- Evolution -
David Turell,
2009-01-19, 14:34
- Evolution -
George Jelliss,
2009-01-19, 10:36
- Evolution -
dhw,
2009-01-13, 17:57
- Evolution -
David Turell,
2009-01-16, 00:35
- Evolution: Does oxygen level hold the key -
David Turell,
2015-11-03, 16:46
- Evolution: Finding the first lower jaw bone in a fish -
David Turell,
2016-10-22, 15:25
- Evolution: more on finding jawed fish - David Turell, 2022-09-28, 22:26
- Evolution: Findings before oxygen -
David Turell,
2017-02-01, 01:09
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David Turell,
2017-02-10, 15:11
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dhw,
2017-02-11, 12:50
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David Turell,
2017-02-11, 15:24
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dhw,
2017-02-12, 09:11
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2017-02-12, 16:00
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dhw,
2017-02-13, 13:24
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David Turell,
2017-02-13, 16:40
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dhw,
2017-02-14, 12:03
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David Turell,
2017-02-14, 14:25
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2017-02-15, 00:23
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BBella,
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- Evolution: Horses, speciation and environment -
David Turell,
2017-02-14, 14:25
- Evolution: Horses, speciation and environment -
dhw,
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- Evolution: Horses, speciation and environment -
David Turell,
2017-02-13, 16:40
- Evolution: Horses, speciation and environment -
dhw,
2017-02-13, 13:24
- Evolution: Horses, speciation and environment -
David Turell,
2017-02-12, 16:00
- Evolution: Horses, speciation and environment -
dhw,
2017-02-12, 09:11
- Evolution: Horses, speciation and environment -
David Turell,
2017-02-11, 15:24
- Evolution: Horses, speciation and environment -
dhw,
2017-02-11, 12:50
- Evolution: Horses, speciation and environment -
David Turell,
2017-02-10, 15:11
- Evolution: Finding the first lower jaw bone in a fish -
David Turell,
2016-10-22, 15:25
- Evolution: Does oxygen level hold the key -
David Turell,
2015-11-03, 16:46
- Evolution -
David Turell,
2009-01-11, 17:03
- Evolution -
George Jelliss,
2009-01-11, 16:31
- Evolution -
David Turell,
2009-01-11, 14:35
- Evolution -
David Turell,
2008-11-10, 18:56
- Evolution -
Carl,
2008-11-10, 16:15