@Setanta,
Let's take your definition of religion-- "embracing an organized superstition". For this to make any sense we have to define "superstition", I propose that a superstition is a widely held belief with no scientific backing.
Of course religion is a product of evolution.
It is obvious that religion is human nature, Widely held organized superstitions have been at the core of nearly every society throughout history history.
The evolutionary benefits are clear for social creatures such as are own. For our survival, we needed to form societies that were organized under a clear set of principles-- the principle varied from society to society, but every society developed a set of underlying beliefs that were very useful to forming functional societies.
Religion is as much a product of evolution as any other human trait-- music, art.
If religion isn't a part of evolution-- where would you say it comes from?