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it took billions of years for oxygen to saturate the atmosphere. it has been building up slowly since about 3.5 billion years ago.
around 2.5 billion years ago levels were enough for life to slowly start moving out of the seas (there needed to be enough ozone to weaken the suns strong UV radiation)
Life until about 530 million years ago was nothing more complex than bacteria
Wiki User
∙ 14y ago
Wiki User
∙ 14y agosome organisms changed their metabolism. some cells and forms of life became extinct. aerobic respiration emerged.
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How long would it take to populate the earth?
It took 4600 million years to populate the earth with the life we have on it today.
How long did it take to populate the earth in biblical times?
shutup
Is there oxygen on Haumea?
I'm not sure, but there is oxygen on most planets, most not having enough for earth organisms to survive.
What caused oxygen levels to change in the permian period?
the amount of animals breathing in the oxygen, and not enough plants.
What animals would survive on Pluto?
No Earth animal could survive on Pluto; it's cold enough there that for most of the year oxygen is a rock.
How long would it take to populate the earth?
It took 4600 million years to populate the earth with the life we have on it today.
What are the four races that populate the Middle Earth?
Lots of races populate Middle Earth, but the most famous ones are : -> Elves -> Humans -> Dwarves -> Hobbits -> Goblins
How many boys and girls populate the earth?
---- I have no idea == ==
How long did it take to populate the earth in biblical times?
shutup
Is there oxygen on Haumea?
I'm not sure, but there is oxygen on most planets, most not having enough for earth organisms to survive.
What planets can humans survive on?
Earth. Only earth so far, maybe mars if there was water and enough oxygen
Why are genders different?
So we are able to populate the earth. same with animals.
As life began to populate earths surface what change was seen in the atmosphere?
more oxygen was consumed
Why doesn't the moon have enough oxygen?
the reason the moon has not got enough oxygen is because the moon has no ozone layer so it has the same amount of air as the earth but it just escapes into the galaxy
How did Cain and abel populate the earth?
Cain had no choice but to marry his sisters and have children.
Can you live anywhere besides earth?
Not at this time. Perhaps if enough oxygen and food were brought along.
How do you put population in a sentence?
population model is an example of population .
