=[ I need help with astronomy homework. haha.
2007-09-27 21:03:17 · 4 answers · asked by autumn k 1 in Science & Mathematics ➔ Earth Sciences & Geology
Because the cyanobacteria had to evolve and adapt to its harsh environment, but oxygen was at a little amount, when the arrival of this organism came, it took in CO2 and made it into O2, then flora flourished then came fauna that cycled this kind of process on and on.
2007-09-28 00:07:07 · answer #1 · answered by Anonymous · 0⤊ 0⤋
Not billions of years. It took only several hundred millions of years before the evolution of cyanobacteria (blue-green algae) put a significant amount of oxygen into the air. The historical study of atmospheric constituents, known as the GEOCARB study, show that the atmospheric content of oxygen has varied greatly from its current 21%. During much of the Permian, 300-251 million years ago, the amount of oxygen in the air was 35%. During the rise of the dinosaurs in the Triassic it was only 10-15%.
2007-09-28 08:29:58 · answer #2 · answered by Dendronbat Crocoduck 6 · 0⤊ 0⤋
Right! Cyanobacteria. Now for the real explanation. Oxygen is a very reactive and electronegative element. It wants to combine with anything nearby. This process is called oxidation, rapid oxidation is fire and non-rapid oxidation turns iron into rust. It takes a substantial amount of energy to break these bonds. This process is called reduction. Yes, it was due to cyanobacteria, but that is the end product, not the reason for the end product.
2007-09-28 13:17:15 · answer #3 · answered by Amphibolite 7 · 0⤊ 0⤋
the cyanobacteria had to evolve, and later the plants. both use photosynthesis. earth had to cool before either could happen.
2007-09-28 04:10:55 · answer #4 · answered by The Instigator 5 · 3⤊ 0⤋