A new study, published in the October Current Anthropology, explains why pygmies are small:
“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.