Pooled energy budget and human life history

Reiches, Meredith W.; Ellison, Peter T.; Lipson, Stephen J.; Sharrock, Katherine C.; Gardiner, Eliza; Duncan, Laura

doi:10.1002/ajhb.20906

Cited by 87 publications

(69 citation statements)

References 85 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, public health research in western populations demonstrates that socioeconomic status is multi-dimensional and dynamic across the life course, so that choice of measure can influence results considerably [57]. Furthermore, practically all studies conceptualize and measure resource access at the individual level, but this is unlikely to provide an accurate representation when in reality resources occupy 'pooled energy budgets' shared between kin and non-kin [58].…”

Section: (B) Socioecological Contextmentioning

confidence: 99%

Parental investment and the optimization of human family size

Lawson

Mace

2011

Phil. Trans. R. Soc. B

148

126

View full text Add to dashboard Cite

Human reproductive behaviour is marked by exceptional variation at the population and individual level. Human behavioural ecologists propose adaptive hypotheses to explain this variation as shifting phenotypic optima in relation to local socioecological niches. Here we review evidence that variation in fertility (offspring number), in both traditional and modern industrialized populations, represents optimization of the life-history trade-off between reproductive rate and parental investment. While a reliance on correlational methods suggests the true costs of sibling resource competition are often poorly estimated, a range of anthropological and demographic studies confirm that parents balance family size against offspring success. Evidence of optimization is less forthcoming. Declines in fertility associated with modernization are particularly difficult to reconcile with adaptive models, because fertility limitation fails to enhance offspring reproductive success. Yet, considering alternative measures, we show that modern low fertility confers many advantages on offspring, which are probably transmitted to future generations. Evidence from populations that have undergone or initiated demographic transition indicate that these rewards to fertility limitation fall selectively on relatively wealthy individuals. The adaptive significance of modern reproductive behaviour remains difficult to evaluate, but may be best understood in response to rising investment costs of rearing socially and economically competitive offspring.

show abstract

Section: (B) Socioecological Contextmentioning

confidence: 99%

Parental investment and the optimization of human family size

Lawson

Mace

2011

Phil. Trans. R. Soc. B

148

126

View full text Add to dashboard Cite

show abstract

“…Although infants of most species are nutritionally independent after weaning, humans wean infants early and continue to provide nutrition for them for many years. Both mothers and their offspring are supplemented with resources from other group members, including fathers, grandparents, older siblings, and unrelated allies (29)(30)(31)(32). As a consequence, tradeoffs between reproductive rate and offspring quality are likely to be mitigated.…”

mentioning

confidence: 99%

Faster reproductive rates trade off against offspring growth in wild chimpanzees

Thompson

Muller

Sabbi

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Life history theory predicts a trade-off between offspring quality and quantity. Among large-bodied mammals, prolonged lactation and infant dependence suggest particularly strong potential for a qualityquantity trade-off to exist. Humans are one of the only such species to have been examined, providing mixed evidence under a peculiar set of circumstances, including extensive nutritional provisioning by nonmothers and extrasomatic wealth transmission. Here, we examine trade-offs between reproductive rate and one aspect of offspring quality (body size) in wild chimpanzees (Pan troglodytes schweinfurthii), a species with long periods of infant dependence and little direct provisioning. Juvenile lean body mass, estimated using urinary creatinine excretion, was positively associated with the interval to the next sibling's birth. These effects persisted into adolescence and were not moderated by maternal identity. Maternal depletion could not explain poor offspring growth, as older mothers had larger offspring, and low maternal energy balance during lactation predicted larger, not smaller, juvenile size. Instead, our data suggest that offspring growth suffers when mothers wean early to invest in new reproductive efforts. These findings indicate that chimpanzee mothers with the resources to do so prioritize production of new offspring over prolonged investment in current offspring.life history | growth | reproduction | primates | weaning P arents face a fundamental life-history trade-off between producing more offspring and investing in the quality of each progeny (1-4). This offspring quality-quantity trade-off, along with a trade-off between reproductive investment and parental survival, means that maximizing reproductive rates is often not the strategy that maximizes fitness (5-7). The quality-quantity trade-off has been empirically demonstrated in species that produce litters or clutches, where large litter size often leads to small offspring size, slow growth rates, and reduced survival, particularly under conditions of ecological stress (8-11). Comparative analyses also support a negative interspecific relationship between reproductive rate and offspring size (12, 13). The quality-quantity trade-off has rarely been examined in species for which single births are the norm, and for which reproductive rate is determined by the interval between successive births. Such species are important tests of the model, as a slow breeding strategy suggests a particularly potent trade-off between offspring investment and reproductive rate. Understanding how individuals negotiate this trade-off can provide important insights into the evolution of reproductive biology and behavior.Data on humans are valuable because humans invest intensively in offspring, yet have highly variable reproductive rates. Many studies find the predicted negative relationship between reproductive rates and offspring growth or health (14-18) or demonstrate fitness maximization at intermediate levels of fertility (19-21). For example, when a water tap was ...

show abstract

“…In the another-mouth-to-feed scenario, delayed maturation is favored because it allows ego to accumulate more embodied capital and become a better parent (52). In the helper-at-the-nest scenario, delayed maturation is favored because ego obtains greater returns from indirect investment in a younger sib than from direct investment in his or her own offspring (53,54). The two scenarios are, of course, not mutually exclusive: A child can both compete with his or her sibs for limited resources and provide help to his or her parents.…”

Section: Sexual Maturationmentioning

confidence: 99%

Genomic imprinting and the evolutionary psychology of human kinship

Haig

2011

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Genomic imprinting is predicted to influence behaviors that affect individuals to whom an actor has different degrees of matrilineal and patrilineal kinship (asymmetric kin). Effects of imprinted genes are not predicted in interactions with nonrelatives or with individuals who are equally related to the actor's maternally and paternally derived genes (unless a gene also has pleiotropic effects on fitness of asymmetric kin). Long-term mating bonds are common in most human populations, but dissolution of marriage has always affected a significant proportion of mated pairs. Children born in a new union are asymmetric kin of children born in a previous union. Therefore, the innate dispositions of children toward parents and sibs are expected to be sensitive to cues of marital stability, and these dispositions may be subject to effects of imprinted genes.father absence | helper-at-the-nest | menarche | kith | divorce "The burden of making and the duty of exacting compensation ran on the mother's side as well as the father's. A father and son, or two halfbrothers, would for the purposes of the blood-feud have some of their kindred in common, but by no means all." (1)

show abstract

Pooled energy budget and human life history

Cited by 87 publications

References 85 publications

Parental investment and the optimization of human family size

Parental investment and the optimization of human family size

Faster reproductive rates trade off against offspring growth in wild chimpanzees

Genomic imprinting and the evolutionary psychology of human kinship

Contact Info

Product

Resources

About