Energetics and reproductive effort

Ellison, Peter T.

doi:10.1002/ajhb.10152

Cited by 448 publications

(340 citation statements)

References 63 publications

Supporting

Mentioning

316

Contrasting

Unclassified

Order By: Relevance

“…Energy costs include competition and mate attraction, as well as protection of and provisioning for mates and offspring (Muehlenbein & Bribiescas, 2005). While male mating effort may therefore be considered as largely behavioral, it does have important physiological correlates stemming from the need to signal underlying quality (Ellison, 2003; Zahavi, 1975). …”

Section: Discussionmentioning

confidence: 99%

“…It was hypothesized that markers of investment in reproductive function (Demas, Zysling, Beechler, Muehlenbein, & French, 2011) will decrease in magnitude, allowing for an increase in markers indicative of investment in short‐term survival. This is due to the high costs of male mating effort (Ellison, 2003) and the suggestion that survival may be prioritized over other processes (Bronson, 1991). …”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Short‐term resource allocation during extensive athletic competition

Longman

Prall

Shattuck

et al. 2017

American J Hum Biol

View full text Add to dashboard Cite

ObjectivesFollowing predictions from life history theory, we sought to identify acute trade‐offs between reproductive effort (as measured by psychological arousal) and somatic maintenance (via functional measures of innate immunity) during conditions of severe energetic imbalance.MethodsSixty‐six male ultramarathon runners (ages 20 to 37 years) were sampled before and after a lengthy race. Saliva and sera were collected for testosterone and immunological analyses (hemolytic complement activity and bacterial killing ability). Lean body mass was assessed by bioelectrical impedance, and libido was measured using a slideshow of arousing and neutral images.ResultsFollowing predictions, there was a significant decrease in salivary testosterone levels (109.59 pg/mL versus 97.61 pg/mL, P < .001) and arousal scores in response to provocative images (5.40 versus 4.89, P = .001) between prerace and postrace time points. Additionally, participant bacterial killing ability (P = .035) and hemolytic complement activity (P = .021) increased between prerace and postrace.ConclusionsDecreased libido and testosterone with concomitant heightened innate immune responses suggest a shift in energetic priorities away from reproduction and toward maintenance/defense during a period of energetic stress.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Short‐term resource allocation during extensive athletic competition

Longman

Prall

Shattuck

et al. 2017

American J Hum Biol

View full text Add to dashboard Cite

show abstract

“…Among humans and non-human great apes, even small improvements in energy balance confer significant advantages on survival and reproductive success (Ellison et al, 1993;Knott, 2001;Ellison, 2003;Emery Thompson et al, 2007;Emery Thompson and Wrangham, 2008). The more that food processing increases net energy gain, therefore, the greater its expected effects on human evolutionary biology.…”

Section: The Impact Of Cooking On Human Evolutionmentioning

confidence: 99%

The energetic significance of cooking

Carmody¹,

Wrangham²

2009

Journal of Human Evolution

334

220

View full text Add to dashboard Cite

While cooking has long been argued to improve the diet, the nature of the improvement has not been well defined. As a result, the evolutionary significance of cooking has variously been proposed as being substantial or relatively trivial. In this paper, we evaluate the hypothesis that an important and consistent effect of cooking food is a rise in its net energy value. The pathways by which cooking influences net energy value differ for starch, protein and lipid, and we therefore consider plant and animal foods separately.Evidence of compromised physiological performance among individuals on raw diets supports the hypothesis that cooked diets tend to provide energy. Mechanisms contributing to energy being gained from cooking include increased digestibility of starch and protein, reduced costs of digestion for cooked versus raw meat, and reduced energetic costs of detoxification and defense against pathogens. If cooking indeed consistently improves the energetic value of foods through such mechanisms, its evolutionary impact depends partly on the relative energetic benefits of non-thermal processing methods used prior to cooking.We suggest that if non-thermal processing methods, such as pounding, were used by Lower Paleolithic Homo, they likely provided an important increase in energy gain over unprocessed raw diets. However, cooking has critical effects not easily achievable by nonthermal processing, including the relatively complete gelatinization of starch, efficient denaturing of proteins, and killing of foodborne pathogens. This means that however sophisticated the non-thermal processing methods were, cooking would have conferred incremental energetic benefits. While much remains to be discovered, we conclude that the adoption of cooking would have led to an important rise in energy availability. For this reason, we predict that cooking had substantial evolutionary significance.

show abstract

“…2012). In the context of life‐history theory, investment in metabolically demanding activities such as growth and reproduction (Ellison 2003; Wiersma et al. 2004; Arnott et al.…”

Section: Introductionmentioning

confidence: 99%

Plasma markers of oxidative stress are uncorrelated in a wild mammal

Christensen

Selman

Blount

et al. 2015

Ecology and Evolution

View full text Add to dashboard Cite

Oxidative stress, which results from an imbalance between the production of potentially damaging reactive oxygen species versus antioxidant defenses and repair mechanisms, has been proposed as an important mediator of life‐history trade‐offs. A plethora of biomarkers associated with oxidative stress exist, but few ecological studies have examined the relationships among different markers in organisms experiencing natural conditions or tested whether those relationships are stable across different environments and demographic groups. It is therefore not clear to what extent studies of different markers can be compared, or whether studies that focus on a single marker can draw general conclusions regarding oxidative stress. We measured widely used markers of oxidative damage (protein carbonyls and malondialdehyde) and antioxidant defense (superoxide dismutase and total antioxidant capacity) from 706 plasma samples collected over a 4‐year period in a wild population of Soay sheep on St Kilda. We quantified the correlation structure among these four markers across the entire sample set and also within separate years, age groups (lambs and adults), and sexes. We found some moderately strong correlations between some pairs of markers when data from all 4 years were pooled. However, these correlations were caused by considerable among‐year variation in mean marker values; correlation coefficients were small and not significantly different from zero after accounting for among‐year variation. Furthermore, within each year, age, and sex subgroup, the pairwise correlation coefficients among the four markers were weak, nonsignificant, and distributed around zero. In addition, principal component analysis confirmed that the four markers represented four independent axes of variation. Our results suggest that plasma markers of oxidative stress may vary dramatically among years, presumably due to environmental conditions, and that this variation can induce population‐level correlations among markers even in the absence of any correlations within contemporaneous subgroups. The absence of any consistent correlations within years or demographic subgroups implies that care must be taken when generalizing from observed relationships with oxidative stress markers, as each marker may reflect different and potentially uncoupled biochemical processes.

show abstract

Energetics and reproductive effort

Cited by 448 publications

References 63 publications

Short‐term resource allocation during extensive athletic competition

Short‐term resource allocation during extensive athletic competition

The energetic significance of cooking

Plasma markers of oxidative stress are uncorrelated in a wild mammal

Contact Info

Product

Resources

About