ESPE Yearbook of Paediatric Endocrinology

Sci Rep 2021; 11:274. doi: 10.1038/s41598-020-79501-w

– Variation in human stature and limb proportions reflects not only thermal adaptation but also environmental stressors– The authors analysed global variation in stature and limb length using published anthropometric data from adult male and female populations across the world in relation to climate and net primary productivity, taking into account population history– Net primary productivity was a consistent negative predictor of anthropometry, which may reflect the growth limiting effects of lower environmental resource accessibility and/or pathogen load

It is accepted that increasing distance from the equator is associated with higher body mass and shorter limbs relative to the trunk. Lower temperature, a variable that is directly related to increasing distance from the equator, is often cited as the main factor that explains these differences between populations. The authors attempted to tease out these widely cited associations between human phenotypic variation and climate, taking into account population history (broad pattern of human dispersal both within and outside of Africa). In addition to temperature, they considered other direct climate variables such as humidity, and indirect climate variables such as environmental productivity (which covaries with, e.g. nutrition, diet, pathogen load). Most models suggested that population history had an influence that was at least as important as the climate effect on limb length, sitting height and stature. After correcting for population history, temperature appeared as the main factor explaining variations between populations. However, humidity and indirect climate variables also played a role. The models yielded grossly similar results for males and females.

Overall, population history, temperature and other eco-geographical correlates (food availability, pathogen load) are all associated to stature and limb lengths (although causation was not demonstrated). This study is interesting, not only because it attempts to understand differences in anthropometric characteristics between populations, but also because it serves a reminder that our understanding of growth in children and adolescents needs to take context into consideration.