To the fellow who's stated that we only use 10% of our brain power, you've fallen for a myth. We use 100% of our brain power, there is no "untapped" part of the human brain. Well, at least in my opinion - parts of my brain regulating my body functions aren't what I consider "unused."
To those extrapolating a galactic formula for emergent intelligence from Earth's evolutionary record: huh? What does one have to do with the other? Earth's biosphere is a seething cauldron of competing species and any given "M-class" planet will evolve life, if any, in practically complete isolation from the rest. This method is so problematic as to be useless. Sorry if that's a strawman but it seemed like that's what some were stating.
turbo-1 said:
If we hold our own intelligence up as the yardstick by which all other creatures will be judged as "intelligent" or brute animals, we have lost sight of how intelligence develops in a continuum.
Yeah, but the point of most "intelligent species" discussions like this one, at least ultimately, is to guess at how many "this is my boom stick" species there are, not how many truly sentient species there are. Technology creation and organizational capacity are basically the yardstick here, but it's easier to say "intelligence."
Personally, I think that as a biosphere progresses the chances of it developing intelligence approach 1:1. (I think intelligence is the ultimate Darwinian survival tool, and that its uses - transhuman boot-strapping for example - are only beginning to be felt). That still leaves a hell of a lot of room for variation since evolutionary time isn't exactly short. It took life on Earth between 2.8 and 3.5 billion years to go from prokaryotes to modern humans. The Earth is about 4.6 billion years old, the Milky Way is about 13.5 billion years old, and the universe isn't much older than that:
http://spaceflightnow.com/news/n0408/17milkyway/
My (extremely uneducated) guess is that there aren't many rival space-faring or would-be space-faring species in the Milky Way, but there's a lot of room for variance. It took quite a few evolutionary waves to produce an intelligent, tool-using, social species on Earth after all, maybe it took far less time in some instances and far more in others? My less uneducated guess is that biological life is probably much more common.
guevaramartyr said:
2) The equation assumes intelligenent civilizations must possesses radio. I don't even need to talk about the flaw in this one.
Yeah, you do. Radio is one of the most basic ways to send communications in many directions at light speed. Even if a species found a better way to broadcast communications, it would be stupid to stop broadcasting in radio IF a species wants to be found.
In a stagnant environment, such as that found in a race existing in deep space, intelligence might well be harmful. However, anywhere there is competition or a rapidly changing environment, intelligence will be a help to a certain point. Once that limit has been reached, new strains will be necessary to enhance intelligence.
I'm not following you here. Intelligence is like a gun in this sense: it's infinitely better to have it and not need it than need it and not have it.
Janus said:
The problem with this is that intelligence has yet to show a long term track record as a trait for survival.
It's shown enough to reasonably extrapolate.
DaveC426913 said:
No way! Dinosaurs ruled the Earth for hundreds of millions of years. Hundreds of millions. Many kinds of bacteria have been on Earth, essentially changed for billions of years.
Imagine if we found a whole branch of creatures that we could (implausibly) find the first development of it, and the last signs of it befiore it died out, and that its whole history was only a few hundred thousand years.
Dinosaurs ruled for hundreds of millions of years, but if the test of Darwinism is survival, then they failed. It matters not a whit how long they ruled. Ironically, "unproven" human intelligence provides one of the few hopes that dinosaurs may live again.
At no point in their history did dinosaurs exhibit the potential to populate an entire galaxy in 100k years or so, humans are within a century of starting such an endeavor. We're within a century (an evolutionary eye-blink) of trumping any measly meteorite impact as an ELE.