Correlations between relatives in small populations

Correlations between relatives in small, closed populations can be substantially smaller than predicted by the classical formulas of population genetics. This effect is especially pronounced for relatives whose most recent common ancestor is several generations removed. When the effective population size is small, correlations between even close relatives can be negative. This implies that in small populations conventional estimators of quantitative genetics parameters will be biased and that preferential treatment of close relatives will be less likely to evolve.