Thanks for the fascinating tid-bit about Ernst Mayr.  I may have heard of him before but I didn't remember the name.

If I had to guess, I'd say that there are probably a great deal of planets with some form of life out there, but on the vast majority of them it's just basic single-celled organisms.  A select few have full-fledged plants and animals, and a tiny minescule portion have intelligent species capable of technology.

Of those, I'd guess that most wipe themselves out relatively quickly, but given the size of the universe there must be a handful who survive and spread across interstellar space.

With 200 billion stars in our galaxy to work with, it's definitely not inconceivable that a few such civilizations are already out there, and that by the time we evolved they might have spread far enough to be aware of us and to have visited us.

Unfortunatley, there's just no good way to assess the likelihood of that, but the default assumption is that it is highly unlikely.

by kemstone on 07/10/2010 05:13:20 AM EST

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