Hmmm... Cut the Numbers, I Just Thought of Something

I was just reading the "CO2" thread - and I started thinking about how we deal with CO2. For the most part, it's used by plants, which turn CO2 and sunlight (as well as some other minerals and water) into glucouse. When the plant cells then consume the glucouse, they essentially take the Carbon out of the CO2, and use it for their own needs. Then they release the O2 back into the air.

We, of course, continue the cycle, and get most of the carbon we need through food. We exhale CO2, and the cycle continues.

How marvelous this little arrangement no?

But that's not what I came to talk about. In a way it is... but in a way it isn't. Step back for a moment and consider how perfectly balanced this is. Not only that, but it's something that is unique to an atmosphere with oxygen and carbon (without oxygen tolerancy, no life would've survived the poisonous release of oxygen into the atmosphere of early earth).

Now, expand this to the theory of life on other worlds. How many places might have started life, but then life was cut short because oxygen tolerancy was not evolved?

And it's not like earth was flooded with oxygen when this first happened. It was only a little bit - but it made a huge impact. Oxygen's actually increased in our atmosphere, and has been linked with a few mass extinctions where there was literally too much oxygen for the creatures to handle.

How much do you think this would cut the Drake equation by?

Now, mind you, there's still likely many other places where life developed - but perhaps it's not as abundant as we would have hoped. Perhaps this is why there's no life on a number of worlds, like Mars. Perhaps the fundamental of the "anti-oxidant" wasn't evolved, or that only oxygen-releasing creatures evolved, or that nothing evolved passed the primordial soup (the original pond of life likely ate itself up - and it was only as food was going short that a small cell-like organism found the secret to make food from the ground, the air, and the sunlight on the then ozoneless planet.

Stuff to think about...

I feel the need to reply.. but at the moment all I can think is

"Man that's deep"

Originally posted by Yarium
How much do you think this would cut the Drake equation by?

Cant cut it at all. Its still a just a theory that we only have one example of.

I wouldnt get hung up on simple oxygen though... Aliens could probably breathe something else, if anything at all.

If evloving life is put in an enviroment that doesn't outright kill it, it will evolve to thrive there given enough time.

Humans are already seeding the solar system via non-sterile probes and what-not.

Spores and some bacteria do just fine in many different enviroments. All they need to a few million years to learn to thrive.

My old science teacher used to discuss some of this balance......and often mentioned that if there was a slightly higher percentage of oxygen in the atmosphere, there would be a lot more instantaneous combustion. Ouch!

I don't know that it's an issue.

Remember, here on Earth, there's lots of things that don't grow in our air (anaerobic bacteria, for one and sea life for another.) Scientists would not be surprised to find organisms that evolved in an atmosphere of 5% oxygen (for example.)

Methane and silicon based lifeforms have long been postulated by science.

So I think the theory (which right now is untestable and unproveable) wouldn't be affected by this.