When two worlds collide.

This special issue of Human Biology commemorates the quincentennial of Christopher Columbus's journeys to the New World. This historical event, the collision of New and Old World cultures, forever altered the demography of the world. As a result of this contact, the native peoples of the Americas experienced innumerable hardships, disease, death, and the destruction of civilizations, tribes, and a way of life. However, Eu­ rope was enriched by the acquisition of an assortment of agricultural products, gold, and a haven for millions of immigrants fleeing perse­ cution and poverty. This collision of the worlds also resulted in the cre­ ation of a unique social experiment, democracy under a constitution, but at a phenomenal cost to the natives of the Americas and to the Africans brought to work the land. We should not celebrate this so-called dis­ covery of the New World, but we can reflect on the 500th anniversary of a profound historic event. This commemorative volume of Human Biology summarizes the available information on the biology of New World populations. Given spatial constraints, I solicited contributions that examined the contro­ versial issues of late versus early peopling of the New World and the effects of cultural contacts. The eight articles are grouped temporally; that is, the first section deals with Amerindian populations before Eu­ ropean contact, and the second section describes contemporary genetic and morphological variation.