Hello Friends:
The Search for Extraterrestrial Intelligence (SETI) incorporates the use of radio telescopes to search for extraterrestrial intelligence. Of course, the extraterrestrial intelligence searched for must have developed technology that sends out radio signals. How likely is it that not only has life originated and evolved beyond the earth but that that life has developed technology much like ours?
Since we have only one known example of a planet that has undergone such evolution, the earth, we must look to this planet for clues to this question. What factors have contributed to the current existence of intelligent life on earth, and does evolution anywhere in the cosmos move in the direction of ever increasing cognitive ability on the part of a sizable number of species?
It seems to me that evolution, at least here on earth, has moved in that direction. Some of the earliest species, one-celled animals, had no brains at all. Multicellular animals much later evolved rudimentary brains that enabled those animals to move about looking for food or avoid being the food of some other animal. Recently in geological history species such as dolphins and primates, including humans, have evolved with elaborate brains that confer survival advantages. Brains are very complex, and evolution would take longer to produce brains with greater complexity.
But must evolution take this course, or could it have been completely different? My guess is that yes, evolution seems destined to move in the direction of ever increasing cognitive abilities on the part of many species. If I'm right, the species on other planets probably have evolved intelligence like ours assuming that there has been enough time for that evolution to progress that far. They may very well have radio-wave technology that could be detected by SETI.
What is the opinion of the biological sciences?
Jagella