Escaping youth's double-bind?

Nicholas Wade reports today in the New York Times on a tantalizing study that may offer some insight into the evolution of aging, the subject of my recent Darwin Day lecture. An extended family in Ecuador carries a mutation that seems to leave them completely free of cancer and diabetes. The mutation affects a growth hormone receptor on their cells, so that the cells produce low levels of a growth factor. As I mentioned in my lecture, scientists have studied animals with this same mutation, and they can live to amazingly old ages–the life span of C. elegans worms doubles, for example.

The story with the Ecuadorians is not cut and dried, however. While they may be blissfully free from cancer and diabetes, they don't live to be 160 years old. They die at a normal age of other causes. What's more, as I mentioned in my lecture, the Methuselah worms trade long life for reproductive success–a prediction that comes out of evolutionary theory. There's one obvious trade-off that the Ecuadorian family experiences: they have a severe form of dwarfism. On the other hand, their mutation does not ...