“For example, having a C instead of a T variant at position rs2764264 is associated with longer life. Two of our children, Alex and Natalie, inherited two Cs at this position, one from Sandra and one from me, so all other genes being equal, and as long as they don’t live terribly negative lifestyles, they should have greater odds of reaching age 95 than I do, with my one C and one T, and substantially greater than someone with two Ts.”