Your article notes how groups of people may have different numbers of copies of the amylase gene. Is it correct then that individuals have varying numbers of the gene as well? If so, would this explain why some people don’t like meat and become vegetarians and others just need to eat meat?

Robert Krase
Springville, Calif.

The researchers found that among 50 Arizona college students, the number of copies of the amylase gene ranged from 2 to 15. As for whether this explains vegetarian leanings, researcher Nate Dominy says that because amylase quickly converts plant starch to sugar in the mouth, excess amylase may make eating vegetables “a more rewarding experience .”—B. Vastag