scott at PSYCH.TORONTO.EDU wrote:
: I think this would be the place to ask such a question, so here it is.
: What are the current theories as to why the nervous system is mostly crossed?
: What are the benefits which are thought to be gained from such a setup?
: A novice wants to know. :-)
:scott at psych.toronto.edu | "They are in you and in me; they created us,
: Brian Scott | body & mind; and their preservation is the
: Department of Psychology | ultimate rationale for our existence."
: University of Toronto, Canada | - Richard Dawkins (The Selfish Gene)
I have never read any evolutionary arguments on this topic, but I always
assumed that this occured very early in evolution as a mechanism to allow
self-defense against a directional threat, e.g. fighting a predator on the
left after it had damaged the left side of the head.
I know this is weak, but it's the first thing that popped into my head when
I first learned of this crossing phenomenon as a student.
Steven W. Barger, Ph.D.
Sanders-Brown Center on Aging