The invisible cliff: abrupt imposition of Malthusian equilibrium in a natural-fertility, agrarian society.

ABSTRACT: Analysis of a natural fertility agrarian society with a multi-variate model of population ecology isolates three distinct phases of population growth following settlement of a new habitat: (1) a sometimes lengthy copial phase of surplus food production and constant vital rates; (2) a brief transition phase in which food shortages rapidly cause increased mortality and lessened fertility; and (3) a Malthusian phase of indefinite length in which vital rates and quality of life are depressed, sometimes strikingly so. Copial phase duration declines with increases in the size of the founding group, maximum life expectancy and fertility; it increases with habitat area and yield per hectare; and, it is unaffected by the sensitivity of vital rates to hunger. Transition phase duration is unaffected

SUBMITTER: Puleston C 

PROVIDER: S-EPMC3909123 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature