The past as if nothing ever changes?

I can't quite resist putting up a bit of P.J. O'Rourke's sendup of the Field Museum in one of its institutionally correct and sensitive moments:

A very wordy inscription details the theories of when and how humans arrived in the New World. Translated from the academese: "We dunno." An encomium to the Ice Age hunter-gatherers follows. "People like us," it concludes, "prospered in ancient times." We did indeed--if your idea of prosperity is fastening a "Clovis people" spearpoint to a stick and stabbing long-horned bison, giant grand sloths, wooly mammoths, mastodons, and New World horses until they were all extinct. The economic boom didn't extend to casual wear and sports clothes. Ice Age or no, everyone in the talentlessly painted murals is naked. Nipples seem to have been vague and smudgy in ancient times, and a mastodon or giant ground sloth was always getting in between mural viewers and your genitals.

Dull as dioramas, he thinks. Well then, their story can't be true because our ancestors did not all die out from sheer boredom, as their descendants might, if subjected to much of this.