But we now know that hunter-gatherers like the Ju/’hoansi did not live constantly on the edge of starvation. Rather, they were usually well nourished; lived longer than people in most farming societies; rarely worked more than fifteen hours a week; and spent the bulk of their time at rest and leisure. We also know that they could do this because they did not routinely store food, cared little for accumulating wealth or status, and worked almost exclusively to meet only their short-term material needs. Where the economic problem insists that we are all cursed to live in the purgatory between our infinite desires and limited means, hunter-gatherers had few material desires, which could be satisfied with a few hours of effort. Their economic life was organized around the presumption of abundance rather than a preoccupation with scarcity. And this being so, there is good reason to believe that because our ancestors hunted and gathered for well over 95 percent of Homo sapiens’ 300,000-year-old history, the assumptions about human nature in the problem of scarcity and our attitudes to work have their roots in farming.

Nest-building-and-destroying weaver birds may seem unusually profligate with energy. But they are by no means the only species besides us inclined to spend energy on apparently pointless work. The avian kingdom alone is blessed with thousands of similar examples of expensive elaboration, from the grandiose plumage of birds of paradise to the over-elaborate nests of bowerbirds.

And, taken together with research conducted by anthropologists among geographically isolated peoples who continued to make a living as foragers in the twentieth century, this data suggests that for 95 percent of our species’ history, work did not occupy anything like the hallowed place in people’s lives that it does now.

As farming societies grew more productive and captured more energy from their environments, energy appeared to be scarcer and people had to work harder to meet their basic needs. This was because, up until the Industrial Revolution, any gains in productivity farming peoples generated as a result of working harder, adopting new technologies, techniques, or crops, or acquiring new land were always soon gobbled up by populations that quickly grew to numbers that could not be sustained. As a result, while agricultural societies continued to expand, prosperity was usually only ever fleeting, and scarcity evolved from an occasional inconvenience that foragers stoically endured every once in a while to a near perennial problem. In many respects, the hundreds of generations of farmers who lived before the fossil-fuel revolution paid for our extended lifespans and expanded waistlines now by enduring lives that were mostly shorter, bleaker, and harder than ours, and almost certainly tougher than those of their foraging ancestors.

For fifty years, The Nature Conservancy (TNC) has helped protect environmentally precious areas in the world using the simplest possible method: It buys them. It buys land at market prices, making it off-limits to environmentally damaging uses, such as development or logging. This strategy has come to be known within TNC as “bucks and acres.” It had appeal to donors and benefactors, because the results of their gifts were so clear. A big gift bought a big piece of land. A small gift bought a small piece of land. As one donor commented, TNC produced “results you could walk around on.”

In 2002, Mike Sweeney, the COO of TNC California, was facing a big challenge. California is particularly important to TNC, because it contains so many environmentally critical areas. California is one of only five Mediterranean climate regions in the world. (The others are the fynbos of South Africa, the matorral of Chile, the kwongan of Australia, and, of course, the Mediterranean.) These Mediterranean climate zones occupy only 2 percent of the world’s landmass but host more than 20 percent of its plant species. If you want to buy environmentally precious land, Mediterranean climates give you a lot of bang for your buck.

In 2002, Sweeney and his staff had taken a map of California and colored in the most environmentally sensitive areas, the areas worth preserving. Astonishingly, 40 percent of the map was colored. This was a non-starter: There weren’t enough bucks out there to buy that many acres.