I learned back in undergrad days that our brains see patterns even where none exist; we're pattern-matching machines, is what we are. But I hadn't realized that such functions were lateralized. This hemispheric specialization strikes me as a little reminiscent of "gene duplication": that process by which genetic replication goes occasionally off the rails and serves up two (or more) copies of a gene where only one had existed before. Which is very useful, because evolution can now play around with one of those copies to its heart's content, and as long as the other retains its original function you don't have to worry about screwing up a vital piece of a working system. (This is something the creationists hope you never learn, since it single-handedly blows their whole the-mousetrap-can't-work-unless-all-the-parts-evolve-simultaneously argument right out of the water.) Analogously, I see one hemisphere experimenting with different functions -- imagination, the search for meaning -- while the other retains the basic just-the-facts-ma'am approach that traditionally served the organism so well.
This one's so unabashedly good (the excerpt above is merely prelude) that I was tempted to post it in its entirety.