LordMagnusKain
Banned
- May 10, 2001
- 2,669
- 0
- 0
but what about all that CO2 in the atmosphere, it must be good for protecting the earth from UV/x/gama....Originally posted by: Riprorin
Originally posted by: abj13
Originally posted by: Riprorin
You need O2 to make O3, correct? So without oxygen, there would have been no ozone layer in primitive earth, right?
Life evoled first in water, then on land. Water absorbs light in the UV portion of the spectrum. Ozone is not necessary for life, when water helps absorb light, and UV would also increase the mutation rate. UV is only bad for multicellular organisms, primarily through carcinogenesis.
Originally posted by: Riprorin
A reducing environment is necessary for abiogenesis.How do you reconcile that with the evidence that O2 preceeded photosynthetic organisms?
There's no evidence that the Earth was orginally O2 rich as it is today. Let me put it this way, photosynthesis uses CO2 and light to create "food" and O2. Therefore, the Earth started rich in CO2, the explosion of photosynthetic life caused the atmosphere to shift from CO2 rich into O2 rich.
"Since then, workers have subjected many different mixtures of simple gases to various energy sources. The results of these experiments can be summarized neatly. Under sufficiently reducing conditions, amino acids form easily. Conversely, under oxidizing conditions, they do not arise at all or do so only in small amounts." [L.E. Orgel, Scientific American, Vol. 271, No. 4, p:56 1994]
It seems to me you have a problem. If there is free oxygen then you don't form amino acids, and if you don't have free oygen, you don't have an ozone layer and primitive life would be destroyed by UV.
It seems like a conundrum.
Kyoto lower CO2 emissions treaty due to global warming because CO2 doesn?t reflect solar radiation but traps it? hum....
nope I guess that doesn't work.