THE UNIVERSE WITHIN

In a follow-up to Your Inner Fish: A Journey into the 3.5-Billion-Year History of the Human Body (2008), Shubin (Biological Sciences/Univ. of Chicago) delivers an equally engrossing history of life’s connections to everything else.

The author begins with the most common element in the human body, hydrogen, which also makes up 90 percent of the universe. All hydrogen existed along with helium and a trace of lithium when everything began 13.7 billion years ago. Heavier elements were made later inside stars, some of which end their lives violently. Cosmic dust that condensed to form the sun 5 billion years ago also made the planets. Microorganisms appeared soon after the Earth cooled enough to support liquid water—so soon that many scientists believe that life is not a rare accident, but inevitable under the right circumstances. Shubin recounts the subsequent 4 billion years of changes in both life and its surroundings. Oxygen, absent at first, slowly accumulated as photosynthetic plants multiplied. The Earth’s rocky crust shifted, eroded and cracked, leaking volcanic gases from the interior. Continents formed and split, expanding and shrinking the oceans; the resulting mountains, shifting ocean currents and migrating landmasses carried life across the planet, forcing it to adapt to the changing environment or nearly wiping it out. The sun is 30 percent hotter than when life began; in another billion years, it will make the Earth too warm to support life.

An intelligent, eloquent account of our relations with the inanimate universe.