"Is Highly Intelligent Life Commonplace In the Universe?"

(Click on the title to link to the original space.com thread that inspired this article) We really need to understand the function of evolution; it does not have a 'direction.' As such, there is no 'more evolved' or 'less evolved' species, and there is no 'end point' for evolution to reach as it is continuous and unending throughout the duration of a species' existence. Evolution is the name given to the set of processes by which species undergo changes by reproduction over time in response to prevailing conditions. Sometimes, these conditions are environmental. At such times, we can say that a species undergoing changes in response to environmental conditions is "adapting to better suit its environment." "Natural selection," is the statistical process by which individuals better suited to their environment prosper, while those poorly suited do not, leading to an increased likelihood that better suited individuals survive and reproduce more successfully and often, creating offspring that share their characteristics and improved chances at surviving and reproducing. Over generations, these characteristics can become dominant in the species set, leading to what we call evolution. The complexity of the situation is immense, with every 'act' of evolution riding on the success or failure in life of individuals in the species, and every individual reproducing successfully contributing to the form that evolution will take. Our species' tendency to oversimplify complex systems aptly demonstrates the upper limit of our own intelligence. Sometimes, however, species evolve in response to non-environmental conditions. The environment is ONLY ONE FACTOR influencing evolution, albeit a strongly influential one. We must not forget that evolution is dependent upon reproduction, so any factor that influences reproductive success within a species has to be accounted for. Ooh, yeah, baby, I'm talking about SEXUAL PREFERENCES! As pointed out, INTELLIGENCE comes in a variety of forms, and may best be defined as the ability to solve problems. The life-essential problems are relatively (by our standards) simple, like acquiring sustenance while avoiding BECOMING sustenance, finding shelter and reproductive opportunities, and our world is replete with examples of species who can solve these problems, and therefore deserve to be called "Intelligent," to this extent. At some point far short of that required to solve problems of space-flight, the level of intelligence is sufficient for individuals of a species to start making informed decisions about their potential reproductive partners. You only have to go to your nearest nightclub to test the validity of this hypothesis! As a case study in point, I'd like to cite the Irish Elk (http://en.wikipedia.org/wiki/Irish_Elk), for whom SEXUAL SELECTION tendencies in the species may have played a part large enough to reduce the influence of environmental factors and NATURAL selection processes in the ongoing evolution of the species, presumably leading to the decline and eventual extinction of that species. The same "Bigger Is Better," sexual preference running contrary to environmental forces is evident amongst male lions, too: their large mane, whilst serving as a symbol of mature masculinity, is a considerable handicap to the animal when hunting - their prey often see that big mop coming! Which is probably why the female of that species is the more active and successful hunter. Lions mitigate against the negative survivability characteristic of 'big hair' through social channels, i.e. the females keep their chosen males in the style to which they have become accustomed, sharing food to 'keep them sexy.' Our own species' evolution points to a similar sexual selection tendency at work, with progressive generations getting taller, even accounting for dietary changes. Again, our social structure and food-sharing habits mitigate against the negative survivability characteristic of increasing size, but this could change in the future in response to something such as a global food crisis. Our own ingenuity is an active influence in the evolution of our species, some might argue even eclipsing the strength of natural selection forces in the ongoing evolution of our species. Instead of being shaped BY our environment, we shape the environment to suit us. Of course, not all the environmental changes we have wrought are necessarily beneficial to us, and there are many problems we still need to resolve - again, often due to an oversimplified understanding of the systems we have influenced. But it's NOT all about SIZE! Many species of fish and birds have males with 'courting' attributes, e.g. brightly patterned plumage or oversized appendages which do not improve the chances of survival of individuals in terms of food acquisition or predator avoidance, but which DO improve the individual's chance of reproducing successfully. Often, we can observe a trade-off between natural and sexual selection. Which brings me to my point - why ARE humans 'more' intelligent than the other lifeforms we share this planet with? Eliminating any divine source of intelligence, and sticking to what we can demonstrate and infer from what we KNOW, rather than what we BELIEVE, quite simply, humans are intelligent because humans find high intelligence sexy! Just as with the Irish Elk's antlers and the lion's mane, sexual selection for higher intelligence within our species has led to the development of the 'Human Level Intelligence' we currently enjoy. Because we enjoy it so much, we tend to think of ourselves and any other highly intelligent species as superior and more desirable than the merely 'animally intelligent,' and in so doing we generally overestimate the importance of high intelligence in the evolutionary process. Evolution does not IN ANY WAY select preferentially for high intelligence. Individual survival and success in reproduction influences evolution, and insofar as intelligence serves these purposes it is a postive factor. However, it has yet to be proven that HIGH intelligence such as that manifested by our own species is a positive factor for survivability in the long run, or another case of unmitigatable maladaption which might lead to our own extinction, as may have been the case with the Irish Elk. How, you might ask? Well, a LITTLE knowledge can be a dangerous thing, and I have already pointed out our species' tendency to oversimplify a complex sytem. Until we have a FULL understanding of our universe there is always a risk that one of the environmental changes we instigate in the pursuit of the success of our species could run out of our control and be the death of us. There's also our remarkable ingenuity in devising new methods to DELIBERATELY kill other members of our species to be taken in to account.... So, is Human Level Intelligence (or greater) widespread in the Universe? Probably not too common, even if life is 'ubiquitous' where conditions permit it. But one thing is for sure - the chance of encountering highly intelligent life out there in the depths of space, slim or otherwise, is the driving incentive for many behind all space exploration. And why? Because it's so damn SEXY! On the bright side, we can expect that any other highly intelligent species we might encounter would have at least one thing in common with us, and what a thing to have in common! Thanks to space.com for hosting a fascinating series of postings on this issue - 170 and counting, and running for MONTHS! Thanks to Chris for the original posting, for sticking your neck out for your beliefs, and for fanning the flames of controversy to keep this thread hot for so long. And thanks to everyone who contributed. P.S.: Douglas Adams has the funniest line on the existence or otherwise of intelligent life in the universe (while we may not agree with the logic of his calculation...) "It is known that there are an infinite number of worlds, simply because there is an infinite amount of space for them to be in. However, not every one of them is inhabited. Therefore, there must be a finite number of inhabited worlds. Any finite number divided by infinity is as near to nothing as makes no odds, so the average population of all the planets in the Universe can be said to be zero. From this it follows that the population of the whole Universe is also zero, and that any people you may meet from time to time are merely the products of a deranged imagination."