Here is something more intriguing. One of the Glise planets is tidally locked to its parent star, like Mercury. One side faces its star, the other dark. On the sides may be a thin habitable zone of perpetual twilight. The planet appears to have a lot of water, but it's solid. And warm. Compressed water. That was from Universe. Now, where have we seen that sort of scenario? A generally uninhabitable place, with a sliver of habitability because a river runs through it? Do we come from Glise?
On of them. It's the compressed water, that's weird. Off hand i can think of some industrial applications. Water that needs no freezing or containers.
It's quite a supposition to assume that genetic complexity has always increased exponentially. What evidence do they have for that? I mean, yes, they have evidence that's happened recently but the Cambrian explosion points to fits and starts where genetic complexity has increased much faster than exponential. Edit: never mind, seems they acknowledge this is just a what-if. Not a very well-supported one though.
Quite. Just that last bit--that social and scientific development would be roughly equivalent to those of humans--is completely wrong. Nothing guarantees that genetic complexity will produce intelligent life on another world and, even if it did, nothing guarantees that life would develop along a similar line as ours and, even if it did, even a small variation (1 or 2%) in the timing of that development could result in a difference of thousands of years between us and them. Would you consider us and the ancient Sumerians to be "roughly" at the same level of social and scientific development? How about us and the human beings (presumably) living 3-4000 years from now? This is all interesting speculation, but that's all it is.
