Biological basis of extrapolation to humans from animal drug trials

Abstract

A careful assessment of “life expectancy” from past centuries to the present day leads one to consider how it has gradually increased since the early 19th century, from 35 to 40 years in the period of the Roman Empire to about 53 years for men and 56 for women in 1930-35, to 66 and 70 years respectively from 1955 to 1960, with a tendency at the present time for a further modest increase especially in the female sex.