Evolution of intelligence

Posted on August 4, 2008


The latest issue of The Skeptic has a couple of articles discussing the question of how likely it is for intelligence to evolve. Unfortunately, Zeigler and Schermer, who wrote the articles, both make the same mistake of, at times, confusing the likelihood of humans re-evolving with the likelihood of advanced intelligence re-evolving (assuming humans can be deemed to have it). The problem is that the first is clearly almost impossible. As Steven Jay Gould said, if you reran evolution the result would be very different. However, that says nothing about advanced intelligence. It could evolve in creatures very different from us. The problem is that we do not understand intelligence well enough to be able to talk about it independently of the one example we have, i.e. ourselves.

Another problem with Zeigler’s article in particular is that he only considers microevolutionary processes in his answer to the question of how likely is the evolution of advanced intelligence. This leaves him very sceptical. However, if one considers such macroevolutionary phenomena as major transitions, the argument can be made that advanced intelligence, which appears to be closely linked to complex culture, starts to look far more likely once evolution is given sufficient time (3.5 billion years or so). This is also assuming that the major transitions will remain similar across different evolutionary processes, of course.