By eliminating lifestyle risk factors and infectious disease, people will be healthier and therefore live longer. Life span is a fixed biological constant. A small number of genes regulate maximum life span and therefore genetic alteration is very possible. Michael Rose, a population geneticist, used artificial selection to double the fruit fly s life span. Thomas Johnson, a behavioral geneticist, altered a single gene in the roundworm and also doubled its life span.
Some scientists argue that the idea of a maximum life span is based only on empirical data.
Life span is NOT increasing and the misconception that it is, is a confusion between life span and life expectancy. Death doesn t require disease. Historically, the maximum human life span has not been observed to change. There is experimental evidence that some human cells are programmed to reproduce a limited number of times. Regardless of social or cultural influences, various animal species differ considerably in life span.