NASA discovers unique new life form

My point still stands. If the lakes do not have arsenic in them, THEN THE BACTERIA SERVE NO PURPOSE. Yes, I get it, you said contaminated; as did i.

and if you can tell me of a creature that does nothing but consume without expelling wastes, i'll retract that part of my statement.

It's not an arsenic-based life form, so yo. It will prefer phosphorus over arsenic anyday, but can survive with arsenic. That means it won't use arsenic if it got the possibility to get phosphorus.

This is not a huge step for the evolutionary science I'm afraid: This most likely evolved from life not able to cope with arsenic. It's like when animals couldn't handle the UV-rays and got cancer because of it. Now we're more resistant to it, and we don't die if we walk outside.