Introduction

As in other areas of evolutionary biology, human skeletal remains provide the only direct link to other past and living populations. Some skeletal biologists study bones and teeth to discern prehistoric population relationships while others are primarily concerned with temporal changes that can be interpreted in processual terms. These avenues of research provide insights into population history and adaptation, but, in terms of precedence, historical relationships must always be established before temporal trends in size, morphology, and other skeletal indicators are interpreted in processual terms. To illustrate this point, assume that collections of human skeletal remains from one region date to (a) 10,000, (b) 5,000, and (c) 1,000 years BP. Assume further that the three skeletal series show linear trends for a decrease in tooth size and an increase in stature from (a) to (b) to (c). One cannot attribute these trends to genetic changes (e.g., relaxed selection pressure), environmental factors (e.g., improved nutrition), or behavioral/ cultural modifications (e.g., new food storage or cooking techniques) until it is shown there is an ancestral-descendant relationship between (a) and (b) and between (b) and (c). Changes perceived as temporal trends might instead reflect new populations moving into our hypothetical region at times (b) and/or (c). It should not be assumed that two groups occupying the same space but at different times are somehow related. With the well-documented human penchant for moving around the landscape, this is not the case in many instances.

Tooth morphology has contributed to the resolution of a number of historical problems that have long attracted anthropological interest. For various reasons, dental morphologists have concentrated much of their attention on Asian and Asian-derived populations so our examples focus on Asia, the Pacific, and the New World. Fewer analytical studies have been directed at historical problems in Europe and Africa. Unfortunately for this review, but fortunately for future dental morphologists, there remain a myriad of historical questions beyond those addressed that await a systematic analysis of crown and root trait variation.

The Asian dichotomy: Sinodonty and Sundadonty

Asia, the world's largest continent with the largest living population, includes a wide diversity of habitats, from the world's wettest tropical rainforests (Assam), to deserts, steppes, mountains, and the coldest regions on the planet (Yakutia).