While I don't say the authors are wrong, their view is limited because the Americas were without humans until about 11,000 years ago. Even though the authors cite the fact that humans were stewards of their surrounding environs from the time they occupied them, it's disheartening to note that the Americas were no different than any other continent where humans made landfall in that within about two or three millennia, the megafauna vanished.

This is true for Australia and may well be true for Papua New Guinea. Many scientists have discussed this fact and there is some disagreement about how that occurred, but none can disagree that it didn't.

Here in the Americas we had mammoths, mastodons, very large beavers (some say the size of small cars), huge sloths, horses, camelids, sabre-toothed tigers and lions. All were very long gone before the whites landed in the early 1500's and began their extermination of the natives.

In fact, it's theorized that the buffalo were about to go extinct until disease swept the land and killed off many of the native humans, which made them bounce back in population only to be mass killed again by whites.

300 years after whites got to the US, when Lewis and Clark began their expedition in 1804 across the "unsettled" west, it was like walking through a furniture store with all the big pieces removed. Imagine a large furniture store with no beds, sofas, desks, armoires or large tables. That's lot of space to feature side tables, chairs, and lamps.

That means that for millions of years there was indeed a pristine wilderness in both the north and south Americas.