Evolution as described by Charles Darwin is an scientific theory, abundantly reconfirmed, explaining physical phenomena by physical causes. Intelligent Design is a faith-based initiative in rhetorical argument. Should we teach I.D. in America's public schools? Yes, let's do - not as science, but alongside other spiritual beliefs, such as Islam, Zoroastrianism and the Hindu Idea that Earth rests on Chukwa, the giant turtle.

Identity is such a crucial affair that one shouldn't rush into it.

But private lands development around the periphery of the parks - Grand Teton and Yellowstone - is a crucial issue because if those private lands are transformed from open pastures, meadow, forest land to suburbs, to little ranchettes, to shopping malls, to roads, to Starbucks - if those places are all settled for the benefit of humans, then the elk are not going to be able to migrate in and out of Yellowstone Park anymore. And if the elk can't migrate into the park, then that creates problems for the wolves, for the grizzlies, for a lot of other creatures.

Islands are where species go to die.

Whether you like the label 'Anthropocene' or not, whether you find the prospect of what it signifies inevitable or appalling (or both), the time has come to address its implications, as these thoughtful, battle-tested authors attempt to do. The time has long since come.

Nor are we the culmination of evolution, except in the sense that there has never been another species so bizarrely ingenious that it could create both iambic pentameter and plutonium.

To drown a river beneath its own impounded water, by damming, is to kill what it was and to settle for something else. When the damming happens without good reason . . . then it's a tragedy of diminishment for the whole planet, a loss of one more wild thing, leaving Earth just a little flatter and tamer and simpler and uglier than before.