Chances are you live a stone’s throw away from a Thai restaurant in your neighborhood, and you’ve got a go-to local favorite for pad thai. These days I often find myself traveling north of Berkeley, where there’s quite a few wonderful Thai eateries clustered in Albany, El Cerrito and San Pablo locales.
Thousands of years ago, ancient farmers gained the ability to consume milk as adults without getting an upset stomach. A remarkable mutation let some of them digest lactose sugar. But scientists still puzzle over why that mutation persisted and became prevalent in modern humans.