The life spans of plants and animals vary greatly. Some insects live as adults for only a few hours. Turtles and man may live for A century or more; some trees live for several thousands years. It is generally true that the slower a plant or animal grows, the longer it lives. Age records of animals are mostly for those kept in captivity and are certainly exceptional. Exact dates may be questionable, but the ages given do indicate potential life spans. Few animals in nature die a natural death. As soon as they become weakened by age, they are attacked by diseases or predators or are pushed aside by younger, more vigorous individuals of their kind. By conquering diseases and bettering living conditions, man has increased his life expectancy to about 70 years in places where food is plentiful and heath conditions are good.