TED roundup: random notes

Bill Gates in response to a question about whether improving health in poor countries will lead to a population explosion: When the Gates Foundation started out, it emphasized "reproductive health," a.k.a. population control. (Someone once noted that you can always convince poor people that rich people have too much money and rich people that poor people have too many children.) But they soon discovered that there's a direct relationship between improving health and slowing population growth. The most effective way to get people to have fewer children is to rapidly improve the health prospects of those kids. Speed is important, because it gives parents a chance to react and have smaller families.

Nina Jablonski: Dermatologists have done a good job of warning pale people (like me) that we'd better wear sunscreen if we live in sunny climates. But too little attention has been paid to what happens when dark-skinned people live in northern latitudes or spend their days working indoors. Even moderately pigmented people like Barack Obama are at risk for vitamin D deficiency if they have desk jobs. So we should hope the president takes vitamin D supplements. (Jablonski, a Penn State anthropologist, is the author of Skin: A Natural History.)