Having recently read Eerie Silence, findings like this do underscore the question of just how likely life is. More, given life, is intelligence a given? And if there is intelligence, is scientific expansion style intelligence a given?
I confess these are obvious questions. I had never considered them, though. Is crazy interesting to consider.
I re-read eerie silence every couple of years. Paul Davies is a phenomenal writer. I never even knew about chirality playing a role in looking for life on Mars (basically all Earth DNA from anything has always shown the helix to twist in one direction, but there is no reason why it can't go the other way, so if we find DNA on another planet that twists the other way, it is extremely unlikely to be a contaminant brought on the probe from earth).
Before you can ask these questions, you have to define what "intelligence" is. And it's not at all obvious what the definition would be. And, indeed, whether it's even a quantifiable thing, or a smooth spectrum.
Isn't intelligence just one particular adaptation that helps reproductive success? I'm not sure why it would be more common than flight or warm-bloodedness.
It seems intelligence is more of a 'master key' that unlocks reproductive success in a variety of environments and at large scale. The jury is still out on whether it's a given that intelligence ultimately destroys itself.
The assertion wasn't that it would be more common. Just that it might be inevitable. (Indeed, it seems less common on our earth than either of the things you mentioned, so I don't know why we would think it would be more common.)
And again, I concede that these are somewhat obvious questions. My main assertion at this point is just an affirmation that I find this topic really interesting.
All evidence says it's exceedingly rare. As far as we can tell, it's only emerged once in the entire 3.5 billion year history of life on Earth. On top of that, Earth may be a very rare sample of planets that have intelligent life, among a far larger population of life bearing planets that don't ever give rise to it at all.
Since "intelligence" is ill-defined and "consciousness" can't be measured, some disambiguate with the term "technological". Take what I said to mean that if you prefer. :)
My point: If technological civilizations were common, we'd probably expect to have seen a few pop up in Earth's long history of life. Since it's only us, it's not likely to be more common than "one for every 3.5 billion years of life", and there's no bound how much rarer it could be than that.
I confess these are obvious questions. I had never considered them, though. Is crazy interesting to consider.