If you would live long, choose your parents well

Human longevity appears to have a modest but significant heritable componen t. A recent study in Iceland has added to this evidence by making a unique assessment based on records for an entire population. Although the evidence for inheritance of human lifespans appears robust, there remains considera ble uncertainty about the extent of the genetic versus the nongenetic contr ibution and about the importance of gene-environment interactions. Sex-spec ific patterns of transmission of lifespan between parents and offspring mig ht provide clues to the basis of lifespan heritability, but the reported pa tterns are neither conclusive nor consistent.