INHERITANCE

A compendium of facts and case studies on genes.

Moalem (How Sex Works: Why We Look, Smell, Taste, Feel, and Act the Way We Do, 2009, etc.) examines two main ideas: 1) that your genes are not your destiny—environment and behavior can tune genes up or down or turn other genes on or off in the process of  “epigenetic” control; 2) that nobody is “average.” We are all unique in our DNA and how our lives interact with that endowment, so beware of “average daily requirements” and other recommendations. Moalem illustrates these tenets with intriguing stories—e.g., a chef who switched from his meat-heavy, high-fat diet to emphasize fruits and vegetables only to discover that he felt lousy due to the fact that he suffered from hereditary fructose intolerance. Sadly the author relates the story of a little girl given codeine for pain following a tonsillectomy. She had an extra gene coding for the enzyme metabolizing the drug, which resulted in rapid production of excess morphine, which killed her. Moalem describes studies of stress in infant mice (leading them to “give up” when faced with adverse conditions as adults), dietary influences on bee larvae (those given royal jelly become queens; the others, workers) and bullying (one study shows blunted cortisol responses in adulthood). Moalem argues for the usefulness of knowing your genome but is also concerned that the information could be hacked and used against you. He recommends getting detailed medical histories from relatives and explains how even examining your face can be informative about your genetic history. The author covers a wide range of subjects: rare diseases, what’s bad about vitamins and supplements, drugs used in athletic doping, his case of altitude sickness and more.

Readers may occasionally seek less of Moalem’s enthusiasm and ego, but he has a lot of solid information to convey and a stylish way of telling it.