The aim of this project was to investigate the heritability of longevity and the relative contributions of selection on mean lifespan and sex-specific lifespan to human longevity. The researchers pursued two different computational approaches to the problem: (1) period samples and their associated offspring, and (2) backward genealogical pruning of samples. From this research, they answered whether these two approaches yield different estimates of heritabilities or G-matrices? And if different period samples yield stable estimates of G? They developed a way through which distinct estimates can reduce uncertainty in the overall parameter estimates. This research has resulted in 2 manuscripts entitled “The Marginal Valuation of Fertility and Risk-Sensitive Reproductive Decision-Making during Economic Crises” and “Quantitative Genetic Analysis Reveals Trade-Offs between Age at First Reproduction and Fertility”.