Originally posted by karoly aczel
But the theory of evolution would tell you that life evolves.
So if you find microbes on one planet then the likelihood of finding intelligent life is just a hop,skip, and a jump away.
What the theory of evolution does not tell us is how life gets started. It remains to be seen whether life does in fact get started wherever conditions favour it, or whether something else is required beyond chemicals and energy. If the former, then the monotheistic religions are going to have trouble integrating it into their ideology, IMO.
How long it would take to hop, skip, and jump from microbes to intelligent life, is another kettle of fish. It took a few billion years here, according to the best available evidence. A higher temperature and a different mix of chemicals might decrease the time required elsewhere, whereas a lower temperature might considerably lengthen the time, or preclude higher forms from evolving altogether. The evidence of one planet is not a statistically significant sample.
Moreover, there have been several mass extinction periods in Earth's history. Even if life were to get started on another suitable planet, nothing guarantees that it would survive catastrophes similar to Earth's previous mass extinctions.