| Popis: |
Differences between lowland and highland peoples of the Andes in body size and shape have intrigued students of the hypoxia of altitude for a century or more (see, e.g., Forbes, 1870). Until recently, most of the studies of growth and adult size have, however, focused mainly on the variability of single measurements rather than the use of anthropometric indices or summary measures of multiple anthropometric observations, such as principal components, to assess body proportion or shape. Although not without some inconsistency, these studies have nonetheless described in considerable detail the effects of altitude on body size (for a review, see, Frisancho, 1978). Collectively, they suggest that the main effects are on size for age during growth, but altitude may also affect body proportions and in particular, chest dimensions suchwise as to enhance functional adaptation to the hypoxia of altitude (Frisancho and Greksa, 1989). Ethnicity, on the other hand, appears to have a greater effect on body proportions rather than size. The Aymara, for example, have relatively larger sitting heights, more prominent heads and bony diameters than non-Aymara when altitude is held constant (Palomino, Mueller, and Schull, 1979). However, as commonly used, ethnicity measures population genetic differences rather than actual heritability, and in comparisons between populations living at different altitudes or even within the same altitude, regional differences in environmental factors may be confounded with genetic effects to a greater or lesser extent. |
