On the minimum size of endogamous populations

The survival of small endogamous human populations is investigated by computer simulation. It is shown that (1) populations practicing strict monogamy with no extramarital pregnancy are less likely to survive as endogamous groups than are those in which marriage is not a prerequisite for childbearing ; (2) low fertility—low mortality populations can survive with fewer individuals than can populations subject to high fertility and mortality; (3) avoidance of close consanguinity reduces the probability of population survival, but the effect is much greater when fertility and mortality are low. In addition, an attempt is made to determine which demographic characteristics are likely to be the best predictors of potential population decline or disruption.