Author of the week

Jonathan Losos

Jonathan Losos arguably owes his career to one cranky reptile, said Jane Henderson in the St. Louis Post-Dispatch. As a boy growing up in 1970s suburban St. Louis, Losos persuaded his parents to buy him a caiman, a sharptoothed, marsh-dwelling relative of the alligator. His mother, thinking loneliness was eating at the critter, soon brought home another. Before long, the family’s basement was “full of all manner of reptiles,” says Losos. Though keeping a caiman as a pet has since been made illegal, the experience proved beneficial for Losos, putting him on a path to becoming a Harvard evolutionary biologist. His new book, Improbable Destinies, lays out how his research has helped change scientists’ thinking about how evolution works.

Improbable Destinies also gathers research by many other scientists who’ve recently been building the same case: that evolution is not as random or as slow as biologists long believed. Losos, for his part, studied brown anoles in the Bahamas and found evidence that these lizards developed longer legs across a few generations if they lived on the ground, and shorter legs if they lived in trees. “Evolution, we now realize, is a lot more predictable, a lot more repeatable than we used to think,” he recently told a BBC interviewer. But that doesn’t mean it’s always logical. In his book, Losos highlights the example of the duck-billed platypus, an animal no rational process could have created. And to find another example of a socalled evolutionary one-off, he just looks in the mirror. “Nothing like us ever evolved in the past,” he says. “We only evolved once.” ■