While it's fun to speculate, that's a lot of assumptions: intelligent species, civilization, travel, DNA mutation via UV...
Considering we don't know anything besides Earth, we may not be even in a position to recognize life (let alone intelligent life), since we have such a biased definition of it.
Just as until the microscope invention a whole universe of lifeforms was unknown, we could be looking at things at the wrong space/time scale and missing the obvious. I find this more exciting than the possibility of ever finding carbon-based, spaceship-building creatures.
Considering we don't know anything besides Earth, we may not be even in a position to recognize life (let alone intelligent life), since we have such a biased definition of it.
Just as until the microscope invention a whole universe of lifeforms was unknown, we could be looking at things at the wrong space/time scale and missing the obvious. I find this more exciting than the possibility of ever finding carbon-based, spaceship-building creatures.