Genotype × Cohort Interaction on Completed Fertili

Authors: Daniel A Briley K Paige Harden Elliot M TuckerDrob

Publish Date: 2014/12/10

Volume: 45, Issue: 1, Pages: 71-83

PDF Link

Abstract

Microevolutionary projections use empirical estimates of genetic covariation between physical or psychological phenotypes and reproductive success to forecast changes in the population distributions of those phenotypes over time The validity of these projections depends on relatively consistent heritabilities of fertilityrelevant outcomes and consistent genetic covariation between fertility and other physical or psychological phenotypes across generations However welldocumented rapidly changing mean trends in the level and timing of fertility may have been accompanied by differences in the genetic mechanisms of fertility Using a sample of 933 adult twin pairs from the Midlife Development in the United States study we demonstrate that genetic influences on completed fertility and age at first birth were trivial for the 1920–1935 birth cohort but rose substantially for the 1936–1955 birth cohort For the 1956–1970 birth cohort genetic influences on completed fertility but not age at first birth persisted Because the heritability of fertility is subject to change dynamically with the social context it is difficult to project selection pressures or the rate at which selection will occurElliot TuckerDrob was supported by National Institutes of Health NIH research Grant R21HD069772 Daniel A Briley was supported by NIH training grant T32HD007081 The Population Research Center at the University of Texas at Austin is supported by NIH center Grant R24HD042849

Keywords: