Pygmies’ short stature linked to high death rates
Controversial findings suggest that elevated mortality rates breed small bodies
By Bruce Bower
The Grim Reaper can cut life short and, under the right circumstances, whittle those still standing down to the size of pygmies. That’s the controversial conclusion of a new study, published in the October Current Anthropology, that found that stature declined as death rates rose in three small-bodied populations over a 115-year period.
“We provide the first evidence that pygmy body sizes vary considerably over time, that they correlate strongly with mortality rates and that increasing mortality rates lead to even greater reductions of body size,” says Jay Stock of the University of Cambridge in England.
Stock and Andrea Migliano, both anthropologists at the University of Cambridge, say that their findings support a scenario in which most females are able to reproduce at relatively young ages, probably in response to high mortality rates, This physical trait then becomes more common from one generation to the next. Early-maturing bodies divert physiological resources away from growth, yielding small bodies as a side effect, the researchers hypothesize.