These are my humble thoughts on the subject and I will be happy to stand corrected - in fact I expect it....
Yes, I agree. There is no reason that I can see why the human brain should not be continually evolving - or more to the point - changing. I am not sure that it is evolving in the sense of the textbook definition (which implies development and a refining of an organism that makes it more suitable for its environment), but it will certainly be undergoing mutational changes - a few of which will not be regressive. But without a competetive environment conducive to elimination of those less fit, (stupid people breed as fast as the more intelligent, if not faster etc.), positive changes will not thrive as well, and may in fact only propagate a population by interbreeding. This means that changes may still happen but at a much slower rate and the resultant evolutionary change is more likely to be limited to smaller populations than previously (I am less sure about this though). Although cross-cultural relationships are increasingly more common.
In fact, thinking about it, any mutational changes that are viable but actually diminish the effectiveness of the brain may still be supported and carried into the gene pool by interbreeding, because there is no effective mechanism for killing such people off unless they were so hideously ugly or socially unacceptable that they could find no one to mate with:)
Is it really possible that a civilised race of beings could devolve as well as evolve?
But again this is not entirely correct, as even slightly adverse changes in perceptive powers may make people more prone to accidents, car crashes etc.
I don't know whether I agree that the brain can ever reach a plateau - I think this may be a little short-sighted - there may be a whole raft of ways (in theory) in which our thinking ability or perception may be improved or new functions appear, if the environmental circumstances allowed. But in line with my previous statements, I would agree that the only way future generations will see significant development in the functions of the brain from now on, will be through our own ingenuity.
I suppose that if anything catastrophic happens to our environment (such as massive climate change triggering a mini ice age) then we will see further significant development in line with punctuated equilibria.
I would be interested to see what someone who really knows what they are talking about makes of this.
Regards,
Blacknad.
