Perspectives in Biology and Medicine

AN EXPLANATION OF HIGH DEATH RATES AMONG NEW WORLD PEOPLES WHEN IN CONTACT WITH OLD WORLD DISEASES1 FRANCIS L. BLACK* Almost all peoples brought into contact with the world's cosmopolitan culture since the beginning of the age of European exploration have suffered severe loss of number. This tragedy was not confined to the early phases of global integration, but continues in modern times. Half the Xikrin Indians of the Brazilian Amazon died in 1962 and 1963 when they tried to establish commercial links with the larger Brazilian society [1] and, farther west in the state of Rondonia, 600 of the 800 Surui who were alive when they were contacted in 1980 were dead by 1986 [2]. The immediate cause in these deaths was a wide variety of diseases. Tuberculosis had a major part in the Surui decline, but most deaths were caused by diseases that lack sufficiently distinctive symptoms to be diagnosed [1, 3]. Measles and smallpox were historically important [3—5], but probably more because they could be identified than because their impact was unique. Deliberate or negligent cruelty by the Old World invaders played, and in Guatemala still plays, a role, but it is not clear that this cruelty was worse than that common to the era, or worse than that suffered by imported Africans. If we accept the thesis that disease was the major proximal cause of the decline of New World The author thanks Ann Ranenofsky for posing the problem, Kuldeep Bhatia for access to the HLA data for Papua New Guinea; and A. Ramenofsky, John Holland, and Michel Garenne for suggestions on the manuscript. 1No neutral term distinguishes the highly polymorphic European, Asian and African populations from the populations of the Americas, Australia and the South Pacific that remained separate at least until 1492. The names "Old" and "New World" are used here to make this distinction with acknowledgement of unwanted ethnocentricity. Similarly, "Native" will be used for the people of the New World, in spite of its literal inadequacy.»Department of Epidemiology and Public Health, Yale University School of Medicine, 60 College Street, New Haven, Connecticut 06520-8034.© 1994 by The University of Chicago. All rights reserved. 003 1-5982/94/3702-0844$01 .00 292 Francis L. Black ¦ Death Rates among New World Peoples populations, the question must be asked: Why did disease have such a severe impact on these people in particular? Who Died? Destruction of New World populations occurred on both sides of the Pacific, as well as on its islands, and in southern Africa. The African San people (Hottentots and Bushmen) were first contacted by Bantu speakers from the north. While they clearly suffered severe population loss, we lack the information on their initial population that would permit their inclusion in this analysis. Elsewhere, precontact population estimates were usually based on the earliest census. In this way Kroeber [6] estimated the precontact population of the United States and Canada at 1.1 million and Mexico at 3.2 million. Stewart's estimate for other parts of the Americas was eleven million [7], Schmitt's for Hawaii was 250 thousand [8], and White's for Australia was three hundred thousand [9]. If these data are extrapolated to include Melanesia and other parts of Polynesia, the whole New World population, excluding the San, might have been about eighteen million when first counted. However, we have known ever since the event, that introduced diseases moved far ahead of the European explorers and that indigenous populations were often much reduced before outsiders had a chance to count them. A prominent instance was the smallpox epidemic that preceded Pizarro's 1526 invasion of Peru. Similarly, smallpox spread in 1789 far ahead of the English settlers in Australia [10], and New England had extensive abandoned gardens when English settlers arrived. Dobyns [11] proposed that precontact populations could be estimated better by determining the carrying capacity of the land, under the system of food procurement used in each area, and assuming that human populations would have expanded to fill that niche. In this way, he estimated the precontact population of the United States and Canada at eighteen million. Borah and Cook used essentially the same method...