Cognition, Universal Grammar, and typological generalizations

Two potential arguments are cinsidered for Universal Grammar other than that based on poverty of the stimulus. One stems from the limited number of notions that are grammatically encoded in the languages of the world. The other rests on the fact that of all mathematically possible orders of constituents only a subset is actually attested. Neither limitation appears to follow naturally from cognitive, historical, cultural, processing, or other factors; which makes it plausible to think of them as forced upon us by Universal Grammar, perhaps as a consequence of how it crystallized at some distant point of the evolution of our species