Biobehavioral Adaptation

Laughlin, William

Abstract

The Aleuts, Yupik and Inupiaq Eskimos uniquely compose the only human population that is a) linearly and continuously distributed from the sub-Arctic into the high Arctic, b) culturally and genetically partitioned into three major divisions c) residing different lengths of time (9,000 years and 5,000 years) under the agencies of natural selection prevailing in their geographic domains. They display significant and patterned variation in the aging process in: a) life expectancy, b) osteoporosis, c) cortical bone variables, d) loss of teeth, and e) climatic-nutritional- behavioral variables. Cardiological events and anthropometric dimensions reflect secular change as well as nutritional alterations. The overall picture is clearly one of an unfriendly Arctic. Photon absorptiometry measures bone mineral content and bone width in living and dead. It provides a measure of osteoporosis and, with hormones assayed from blood including vitamin D, will yield information on the early and rapid onset of bone mineral loss for individuals and populations. In the large series of ancestral, pre-contact skeletons the calcaneum and the neck of the femur can be scanned as well as the femoral midshaft. Hip fractures can thus be studied in greater detail. Determination of age at death in skeletons by the osteon-photon method provides data for calculating life expectancy in skeletal series. We need to enlarge our extensive bone core and thin section collection with emphasis on the area between Kodiak and St. Lawrence Islands, the voucher series of Whites, Blacks and Mongloids of known age at death with medical histories, and forensic cases. This distribution provides an externally defined environmental gradient with three genetically similar populations prerequisite for deciphering some of the biological, environmental and cultural factors interacting in the aging process.