Biologist Rupert Sheldrake, in taking the ideas of physics into the biological and physiological realms, offers a strong case for considering seemingly random chance events as dependable energy manifestations.

The new physics indicates that tremendous energy resources lie within each of us and that we are united with energy patterns in the universe. Sheldrake proposes that there are morphogenic fields, or “invisible organizing structures that mold or shape things like crystals, plants, and animals, and [that] also have an organizing effect on behavior.” He posits that these fields contain influences from all of history and evolution. As such, they begin to explain the “lucky coincidences” that sometimes solve our problems.

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.

After all, many of the things humans expend energy on—from building ever grander, more ostentatious skyscrapers to running ultramarathons—are hard to reconcile with reproductive fitness or survival. Indeed, many of the things we do to expend energy risk reducing our lifespans rather than extending them. It may well be that the ultimate explanation for why weavers build with such profligacy is that, like us, when they have surplus energy, they expend it by doing work in compliance with the law of entropy.

Turnbull’s descriptions of BaMbuti life evoked something of the deep logic that shaped how foragers thought about scarcity and about work. First, they revealed how the “sharing” economies characteristic of foraging societies were an organic extension of their relationship with nurturing environments. Just as their environments shared food with them, so they shared food and objects with one another. Second, they revealed that even if they had few needs that were easily met, forager economies were underwritten by the confidence they had in the providence of their environments.

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.