Updated on 17th June 2015
When it comes to evolution, it really boils down to two things: not getting killed and creating as many copies of yourself as possible before you are dead. Human may turn out to be among the most intelligent species the process of evolution can produce. That is not to say that intelligent forms more intelligent than us can’t exist in this universe. To illustrate what I mean, suppose we are capable of simulating the universe, it is likely that no matter how many times we run the simulation, organisms with the level of intelligence as humans are the naturally evolved beings with the highest level of intelligence that we can find on every planet with the right conditions to sustain life in each simulation.
Here we define intelligence in terms of the cardinality of the set of problems a certain agent can interpret and devise an algorithm to solve efficiently. An agent, A, is say to have a higher level of intelligence than another agent, B, only and only if the cardinality of A’s solvable problems is larger than that of B’s. This can be seen as a rather lazy approach of defining intelligence, but it outlines the idea of capability which is consistent with our intuitive understanding of intelligence on the level of species (e.g. humans have a higher level of intelligence comparing to chimpanzees as humans are more capable problems-solving-wise) and that is all it matters in this theoretical discussion.
In response to selective pressures, the brain evolves and develops adaptive trait that enables it to perform some computation (e.g. the acquisition of languages for communication) which would bring its host survival and reproductive advantages. With the corresponding factors that result in a higher likelihood for such adaptations, that is how the descendants of an organism can have a higher level of intelligence over time. The rarity of that turns out to be positively correlated with the level of intelligence possessed. We are (apparently) the only species to have reached this level of intelligence on this 4.5 billion years old planet. As we can see, this is a rather unusual level of intelligence to have. It enables the species to learn and make advancement in the methodologies for solving certain problems, and at some point in time capable of ensuring the survival of its members, prolonging their life expectancy, and significantly modifying natural environments, and have absolute domination of all other species it encounters.
However, members of species possessing this level of intelligence (e.g. the Homo Sapiens) would too possess trails from ancestry with lower level of intelligence that were once useful for survival but no longer so and yet still govern some aspects of their behaviors and psychology. It would be highly unlikely that somehow there are intense selective pressures that would increase the frequency of alleles (pre-existing ones or ones newly introduced by mutation) giving rise to higher level of intelligence over time in the gene pool, in any selection driven by the behaviors and psychology on a population level (such as the role cultural preferences plays in the process of sexual selection), or selections driven by other factors. Due to how improbably a species evolves to have this level of intelligence, it would be illogical to consider an even higher level of intelligence to emerge as an effect of allelic drift. It will thus be no surprise that such species often go extinct due to whatever reasons before some of their descendants manage to further evolve to have a higher level of intelligence. And that can a solution to one aspect of Fermi’s paradox as why we have yet come in contact with any extraterrestrial civilization that have developed interstellar travel (suppose such imaginable technology can be easily developed by species with higher level of intelligence than ours).
Now the question is: what about intelligent machines developed by some members of the species collectively? If developed, can the intelligent machines improve themselves and evolve to have an even higher level of intelligence before they meet their end? That is what I am interested in finding out before I meet mine.