INTRODUCTION

In this final chapter the biomedical effects of acculturation and the accompanying changes in lifestyle of the Amerindians who survived the depopulation are considered. The interaction of culture change with the underlying genetics of native people provides a unique opportunity to assess and better understand the mechanisms involved in the etiology of complex diseases. In addition, research into unique Native American responses to various degenerative diseases may shed some light on the mechanisms of interactions between genetic and various environmental factors. The evolutionary consequences of increased genetic admixture between Amerindian populations (resulting from tribes with separate ethnohistories and geographic isolation being forced to coexist in newly created reservations) are also considered in this chapter. The massive infusion of genes from Africans and Europeans into Native American gene pool has undoubtedly altered the risks of diseases in admixed families.

The occupation of the Americas by peoples of Siberian ancestry for possibly 30 000–40 000 years was dramatically disrupted within the past 25 generations (500 years) by a violent collision between Old and New World cultures (see Crawford, 1992a, b). The consequences of this confrontation and the conquest that followed have been, and still are, devastating to the numerical balance that had existed between the environment and the Amerindian populations (see chapter 2). From a total Indian population perhaps approaching 44 million persons at contact, conquest and its numerous sequelae hammered the population down to fewer than 10 million at the nadir. Only recently has the surviving Amerindian population recovered and in some regions of the Americas, such as the Valley of Tlaxcala, begun to increase and perhaps even surpass its pre-Columbian levels (see chapter 2, Fig. 13).