Bone health from an evolutionary perspective: Development in early human populations

Abstract

Skeletal characteristics, bone health, and the risk of osteoporosis differ within and between modern day populations, and almost certainly reflect our evolutionary past. In this chapter, we review the major evolutionary events among the hominins, the human sub-family of primates, and provide an overview of evolutionary mechanisms resulting in the genetic changes that helped our ancestors to adapt to diverse environments. The skeleton can also be affected by a number of environmental and cultural factors, including diet, physical activity, work patterns, health and disease. For the purposes of examining evolutionary aspects of bone health, it is fortunate that bones can be preserved in the fossil record, and certain artifacts of cultural adaptation may also be present in hominin fossil sites. Anthropological techniques have been developed that allow us to create reasonable models of life in past human populations, thereby providing some insight into modern-day bone health. The major biocultural shifts during hominin evolution include the following: expansion from the tropics to a wide range of environments; transition from hunting and gathering to food production; change from physically active lifestyles to relative sedentism; and increase in life expectancy, with changes in reproductive behaviors. These four areas form the focal points for an examination of human bone health from an evolutionary perspective.