A SERIES OF FORTUNATE EVENTS

The award-winning science writer offers evidence that pure chance governs life.

“Look at…all the beauty, complexity, and variety of life,” writes Carroll. “We live in a world of mistakes, governed by chance.” Near the beginning, the author looks at the asteroid that struck Earth 66 million years ago, throwing up so much debris that it blocked the sun, cooling the planet for decades and exterminating most species, including the dinosaurs. Within a few hundred thousand years, the survivors, including mammals, flourished and evolved into many families, including primates and then humans. Such a collision is extremely rare, but humans wouldn’t exist without it. Carroll then offers an expert summary of evolution, a process heavily influenced by geological processes and climate changes that have fluctuated wildly over the past 1 million years, during which our species appeared and grew its large brain. Darwin explained evolution as a series of random variations in offspring that persist if they increase an organism’s reproductive fitness and, over time, spread throughout the species. His work teems with evidence, but scientists found much to quarrel with. Nearly a century passed before discoveries in genetics (the dazzling if clunky mechanism through which variations are passed on) and details of DNA (the engine of genetic changes, itself an ad hoc collection of chemicals) convinced the scientific community. Readers will learn numerous fascinating tales, such as a failed effort to produce a human-chimpanzee hybrid (a “humanzee”), how the ancestors of wooly mammoths from tropical Africa learned to live in the Arctic, and how the AIDS virus jumped from chimps to humans. An amusing coda featuring an invented conversation between dead geniuses and living comedians reinforces the necessity of science even when millions eschew it in favor of a belief that things happen for a reason. Ricky Gervais: “[Science] doesn’t hold on to medieval practices because they are tradition. If it did, you wouldn’t get a shot of penicillin, you’d pop a leach down your trousers and pray.”

A short, sweet, and scientifically solid view of life.