A Grand New Theory of Life’s Evolution on Earth

Sarah Zhang in The Atlantic:

The modern world gives us such ready access to nachos and ice cream that it’s easy to forget: Humans bodies require a ridiculous and—for most of Earth’s history—improbable amount of energy to stay alive.

Consider a human dropped into primordial soup 3.8 billions years ago, when life first began. They would have nothing to eat. Earth then had no plants, no animals, no oxygen even. Good luck scrounging up 1600 calories a day drinking pond- or sea water. So how did we get sources of concentrated energy (i.e. food) growing on trees and lumbering through grass? How did we end up with a planet that can support billions of energy-hungry, big-brained, warm-blooded, upright-walking humans?

In “The Energy Expansions of Evolution,” an extraordinary new essay in Nature Ecology and Evolution, Olivia Judson sets out a theory of successive energy revolutions that purports to explain how our planet came to have such a diversity of environments that support such a rich array of life, from the cyanobacteria to daisies to humans.

More here.