Amanda McGrosky

Duke University | DU

As the tissue most directly responsible for breaking down food in the oral cavity, the form and function of enamel is obviously of evolutionary significance in humans, non-human primates and other vertebrates. Accordingly, a standard metric, relative enamel thickness (RET), has been used for many decades to provide insights into vertebrate and huma...

An often-stated ecomorphological assumption that has the status of ‘textbook knowledge’ is that the dimensions of the digestive tract correlate with diet, where herbivores—consuming diets of lower digestibility—have longer intestinal tracts than faunivores—consuming diets of higher digestibility. However, statistical approaches have so far failed t...

Economic models predominate in life history research, which investigates the allocation of an organism's resources to growth, reproduction, and maintenance. These approaches typically employ a heuristic Y model of resource allocation, which predicts trade-offs among tasks within a fixed budget. The common currency among tasks is not always specifie...

Total energy expenditure (TEE) represents the total energy allocated to growth, reproduction and body maintenance, as well as the energy expended on physical activity. Early experimental work in animal energetics focused on the costs of specific tasks (basal metabolic rate, locomotion, reproduction), while determination of TEE was limited to estima...

Continuous multiday ultramarathon competitions are increasingly popular and impose extreme energetic and nutritional demands on competitors. However, few data have been published on energy expenditure during these events. Here, we report doubly labeled water-derived measures of total energy expenditure (in kilocalories per day) and estimated physic...

Studies of diurnal primates have long considered the nocturnal period to be a time spent merely sleeping and not effectively utilized for foraging or social behaviours. However, digestive activity should continue during the night. To explore the adaptive significance of the primate rumination‐like behaviour, that is, regurgitation and re‐masticatio...

In small-scale societies hunting is a high-risk, high-reward activity which impacts status and reproductive success. The question of whether men hunt to provision families or as a costly signal of their phenotypic qualities has been hotly debated in the anthropological literature. To shed new light on this question, we explored audience assessments...

Recent studies have provided great insight into hominin life history evolution by utilizing incremental lines found in dental tissues to reconstruct and compare the growth records of extant and extinct humans versus other ape taxa. Among the hominins, studies that have examined Retzius periodicity (RP) variation have come to contradictory conclusio...

Although it is generally assumed that among mammals and within mammal groups, those species that rely on diets consisting of greater amounts of plant fiber have larger gastrointestinal tracts (GIT), statistical evidence for this simple claim is largely lacking. We compiled a dataset on the length of the small intestine, caecum, and colon in 42 stre...

While some descriptions of ruminants' dietary adaptations suggest that the length of the intestinal tract reflects the proportion of grass or browse in the diet, this assumption has been questioned. We collated data on body mass (BM), as well as small intestine, caecum, colon/rectum, large and total intestine length in 68 ruminant species, and, whi...

Although typical anatomical features of the digestive tract of carnivores are well known, such as the presence or absence of a caecum in various carnivore taxa, and although a large number of length measurements have been published, the body mass measurement of the corresponding specimens has mostly not been reported. Here, we add original mass and...