The Twitter hashtag #linguistics is ablaze with links to this Scientific American article about Gary Marcus' claim that language is far from "optimal." It's a pretty short and simple article, not much meat, but it has a lot of links (maybe too many?). Money quote:
Visual abilities have been developing in animal predecessors for hundreds of millions of years. Language, on the other hand, has had only a few hundred thousand years to eke out a place in our primate brain, he noted. What our species has come up with is a "kluge," Marcus said, a term he borrows from engineering that means a solution that is "clumsy and inelegant, but it gets the job done."