Definition of the problem - The evolution of human reproduction

Abstract

Mammals exhibit a variety of density-dependent reproductive variables that enable them to come into equilibrium with their environment. These include the age at puberty, extent of embryonic and foetal death, neonatal mortality rate, and the duration of lactational anoestrus or amenorrhoea. These are all female-oriented mechanisms; most mammals are polygynous, and as the female has the greatest energy investment in reproduction she is the limiting resource. Unfortunately, man as a species has chosen to eliminate these constraints, so that we are now without any natural checks and balances on our rate of population growth. We will be entirely dependent on artificial forms of contraception for evermore. Since natural selection has always operated in the past to maximize reproductive potential, women are physiologically ill-adapted to spend the greater part of their reproductive lives in the non-pregnant state. Tomorrow’s contraceptives need to be chosen with great care, as they will have a considerable impact on our general health and social well-being.