Nutritional requirements and human evolution: A bioenergetics model.
Level 5 - mechanism / opinion, no new human data
By design analogy, theoretical bioenergetic modeling and mechanism-based reasoning without direct human experimental data.
PubMed 28524347 · doi:10.1002/ajhb.1310040204
What was done
The authors developed a bioenergetics model to evaluate metabolic requirement shifts across human evolution. They compiled comparative data from extant humans and other anthropoids regarding body size, resting metabolism, brain size, brain metabolism, activity budgets, and foraging patterns. These empirical relationships were used to model and estimate resting metabolic requirements, brain energy demands, and total energy expenditure (TEE) in fossil hominids.
What was found
Anthropoid primates expend approximately 8% of resting metabolism on brain maintenance, compared to 3–4% in other mammals and 20–25% in humans. TEE in anthropoids correlated positively with day range and diet quality. Modeling fossil hominids indicated that Homo erectus experienced substantial increases in both TEE and brain metabolic requirements; its brain metabolism share approached the modern human range, and its estimated TEE was 35–55% higher than that of australopithecines.
Why it matters
The model provides an energetic framework linking hominid brain expansion to shifts in dietary quality, increased foraging range, and the evolution of hunting and gathering behaviors.
Limits
The conclusions derive from theoretical modeling and indirect extrapolations from extant species to fossil hominids. The abstract does not provide sample sizes (n) for extant species or fossil specimens, nor does it report error margins or statistical confidence intervals for the modeled estimates.
Cited by
- supports The brain consumes approximately 20% of the body's daily energy.