Many times, sudden waves of death had wiped out species, genuses, even entire orders. Dinosaurs were only the most glamorous victims of one episode. And yet, across each murderous chasm, plants kept removing carbon dioxide from the air. Animals and volcanoes continued putting it back again, give or take a few percentage points.

Even the so-called greenhouse effect that had everyone worried — melting icecaps, spreading deserts, and driving millions before the rising seas — even that catastrophic outcome of human excess would never rival the great inundations following the Permian age.

Jen very much approved of the way everyone marched and spoke out and wrote letters these days, passing laws and designing technologies to “save the Earth” from twentieth-century errors. After all, only silly creatures fouled their own nests, and humanity couldn’t afford much more silliness. Still, she took her own, admittedly eccentric view, based on a personal, quirky, never-spoken identification with the living world.

Out in the atrium, a low rumble echoed off the walls of the glass cavern. She recognized the deep, purring growl of a tiger, her totem animal according to a shaman she’d spent one summer with, before the last century ended. He had said hers was “the spirit of a great mother cat…”

What nonsense. But oh, what a handsome fellow he had been! She recalled his aroma of herbs and wood smoke and male musk, even though it was hard right now to pin down his name.

No matter. He was gone. Someday, despite all the efforts of people like Pauline, tigers might be gone, too.

But some things endured. Jen smiled as she stroked Baby’s trunk.

If we humans annihilate ourselves, mammalian genes are rich enough to replace us with another, maybe wiser race within a few million years. Perhaps descendants of coyotes or raccoons, creatures too adaptable ever to need refuge in arks. Too tough to be wiped out by any calamity the likes of us create.