Mothers of small-bodied children and fathers of vigorous sons live longer

Abstract

Life-history traits (traits directly related to survival and reproduction) co-evolve and materialize through physiology and behavior. Accordingly, lifespan can be hypothesized as a potentially informative marker of life-history speed that subsumes the impact of diverse morphometric and behavioral traits. We examined associations between parental longevity and various anthropometric traits in a sample of 4,000–11,000 Estonian children in the middle of the 20th century. The offspring phenotype was used as a proxy measure of parental genotype, so that covariation between offspring traits and parental longevity (defined as belonging to the 90th percentile of lifespan) could be used to characterize the aggregation between longevity and anthropometric traits. We predicted that larger linear dimensions of offspring associate with increased parental longevity and that testosterone-dependent traits associate with reduced paternal longevity. Twelve of 16 offspring traits were associated with mothers' longevity, while three traits (rate of sexual maturation of daughters and grip strength and lung capacity of sons) robustly predicted fathers' longevity. Contrary to predictions, mothers of children with small bodily dimensions lived longer, and paternal longevity was not linearly associated with their children's body size (or testosterone-related traits). Our study thus failed to find evidence that high somatic investment into brain and body growth clusters with a long lifespan across generations, and/or that such associations can be detected on the basis of inter-generational phenotypic correlations.

Survival costs and benefits of reproduction: A register‐based study in 20th century Estonia

“…We do not know whether such under‐reporting is systematically related to men's lifespan and offspring number; however, intuitively, one might expect that such incomplete data originate most likely from poorly educated individuals. In most populations, including Estonians, men with poor education have lower chances of becoming longevous 27 . Such bias would mean that a number of (presumably short‐lived) fathers were misclassified as childless men in our dataset.…”

“…In most populations, including Estonians, men with poor education have lower chances of becoming longevous. 27 Such bias would mean that a number of (presumably short-lived) fathers were misclassified as childless men in our dataset. In such a case, the selection for increased longevity in men would be weaker than our calculations indicated.…”

“…For instance, it is possible that uncontrolled reproductive behavior clusters genetically with traits associated with short lifespan, such as impulsivity, sensation‐seeking, and delay discounting (see Refs. 27 and 28). This explanation is supported by the evidence of positive genetic correlations between fertility versus risk‐taking behavior 29,30 and biomarkers of adverse health 16,31 .…”