Birth weight predicted baseline muscular efficiency, but not response of energy expenditure to calorie restriction: An empirical test of the predictive adaptive response hypothesis.

Objectives: Aiming to test the evolutionary significance of relationships linking prenatal growth conditions to adult phenotypes, this study examined whether birth size predicts energetic savings during fasting. We specifically tested a Predictive Adaptive Response (PAR) model that predicts greater energetic saving among adults who were born small.

Methods: Data were collected from a convenience sample of young adults living in Albuquerque, NM (n = 34).

Teen motherhood in cross-cultural perspective.

Teen motherhood is the prevalent childbearing pattern in most traditional populations. Yet early motherhood is associated with negative biological and social outcomes in the developed world. We review the teen pregnancy literature in light of this discrepancy, emphasizing two core debates.

Demographic correlates of paternity confidence and pregnancy outcomes among Albuquerque men.

We examine the demographic correlates of paternity confidence, or men's assessment of the likelihood that they are the genetic father of a particular child. Evolutionary theory predicts that men will provide less parental investment for putative genetic offspring who are unlikely to be their actual offspring, but confidence of paternity has not been as extensively examined as its importance would merit. Using self-reported data on paternity confidence in 3,360 pregnancies reported by men living in Albuquerque, New Mexico, we find that low paternity confidence is more common among unmarried couples and for unplanned pregnancies.

Evolutionary approach to below replacement fertility.

The large human brain, the long period of juvenile dependence, long life span, and male support of reproduction are the co-evolutionary result of the human niche based on skill-intensive techniques of resource accrual. The regulation of fertility under traditional conditions is based upon a co-evolved psychology and physiology where adjustments of investment in offspring depend upon the returns to skill and mortality hazards. When all wealth is somatic, the hormonal system controlling ovulation and implantation translates income into genetic descendants.