h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

it has come to my knowledge that earth itself has had a gadzillon self-regulated processes that allowed life as we know it to evolve, one of the most remarkable (for me) being that the cloroplasts floating around the oceaans quite a while ago almost killed themselves by producing too much oxygen: since they were the only "living" things back then, there was noone around to reduce the level of oxygen in the atmosphere/water, and the level of CO2 plummeted, too. because of that, the cloroplast's evolution and development seems to have been slown down somehow, wich in turn allowed our beloved mitochondriae to jump into existance, and both of them lived happily ever after. (well, kind of)

i haven't read that gaia-book, but it seems to me that it's essentialy about a system "earth" developing and evolving in synergy with itself, that's why i kinda felt like this should be here.

ah well,
nevermind,

-schweini

Its interesting that you bring this up. The fact that the evolution of photosynthetic algae completely changed the chemistry of the earth's atmosphere, in a way that made it harder for the aformentioned organisms to live actually seems to run against the idea of the Gaia theory. This event suggests that life need not have a stabilising effect on conditions on earth, and can in fact exert a destabilising influence.

N