I just thought I'd mention that the Anthropic principle is conceived not as an explanation of life on Earth, but rather a modification of the Copernican principle. Normally in science you assume that your whereabouts are not special with respect to the majority of the universe.
The Anthropic principle modifies this to "Our position is not special up to the fact of our existence". Whether you agree with this or not is another story, but it is genuinely something you have to think about on cosmological scales.
Edited by Son Goku, : Added title.
™ Version 4.2