ONE JULY AFTERNOON last summer, Matt Wilsey distributed small plastic tubes to 60 people gathered in a Palo Alto, California, hotel. Most of them had traveled thousands of miles to be here; now, each popped the top off a barcoded tube, spat in about half a teaspoon of saliva, and closed the tube. Some massaged their cheeks to produce enough spit to fill the tubes. Others couldn’t spit, so a technician rolled individual cotton swabs along the insides of their cheeks, harvesting their skin cells—and the valuable DNA inside.
In graduate school, I earned beer money by modeling for life drawing classes in various art departments. (Don’t judge, grad school doesn’t pay well and beer isn’t free.) In the long hours standing around, I would survey the room and count how many of the aspiring artists were left-handed. Later in my career, I did the same thing—counting lefties, not standing around naked—in the biology classes I taught.