Pattern of growth of lowland and highland Peruvian Quechua of similar genetic composition.

Abstract

The pattern of growth and body composition of 271 lowland Quechua children from the village of Pamashto ( altitude 980 meters ) of the province of Lamas was studied in comparison with that of 313 highland Quechua children from the village of Ondores of the province of Junin (altitude 4150 m). The analysis indicates that, despite the fact that the lowland adults are taller than their highland counterparts, the growth of the lowland children is markedly delayed when compared with that of the highland children. In view of the fact that these samples are genetically very similar, the observed growth differences are probably due to differences in socio-economic and/or other environmental conditions. Measurements of skinfold thickness and estimates of upper arm muscle indicate that lowland children have a lower calorie and protein reserve than those of the highlands. These variations are probably related to various recent negative changes in the ecology and socio-economic condition of lowland populations as well as to climatic factors. As part of a project to determine the mechanisms of human adaptation to environmental stress, we conducted an investigation concerned with patterns of growth of lowland and highland Quechua-speaking Peruvian populations with similar genetic characteristics but living under different circumstances. The results provide evidence of significant growth retardation in the lowland population, when compared with a highland population. Materials and Methods Lowland Sample The study included a sample of 271 Quechua children from the village of Pamashto, in the province of Lamas of the Department of San Martin. These subjects were 6-17 years old. They attended the 1 Center for Human Growth and Development and Department of Anthropology, The University of Michigan, Ann Arbor, Michigan 48104. Human Biology , September 1975 , Vol. 47, No. 3 , pp. 233-243. ©Wayne State University Press , 1975 This content downloaded from 157.55.39.253 on Sat, 11 Jun 2016 06:09:25 UTC All use subject to http://about.jstor.org/terms 234 A. Roberto Frisancho, Gary A. Borkan, and Jane E. Klayman schools of Pamashto and the ages of all subjects were derived from birth records provided by school officials. In addition, a sample of 107 subjects aged 20-40 years was included. Pamashto is located at an altitude of 980 m above sea level. The weather in Pamashto is characterized by hot-humid temperatures. In the winter (May-September), temperatures range from 21 to 27°C with an average relative humidity of 60%. In the summer (OctoberApril), the temperatures range from 27 to 37 °C, with a mean 80% humidity. The village is connected to the town of Lamas by a dirt road, but, due to the intensive rain during most of the year, motorized communication is difficult. Despite this, the inhabitants are in continuous contact with Mestizo populations located in the neighboring towns. At the time of the present study, there was a total of 118 families residing in the village of Pamashto (no official census data exists for this population ) . The economy of Pamashto is based on the cultivation of coffee, cocoa, corn, beans, rice, manioc and bananas, and the herding of pigs. Most of their food is locally produced. Although most inhabitants of Pamashto are bilingual, the native language of the population is Quechua. The Quechua spoken in this village shows great similarity to that spoken in the Central Highlands. During the last years there has been a rapid change in clothing style. The native clothing of men consists of black homespun cotton pants and blue or white cotton shirts. Women wear black or blue cotton skirts and white shirts, of homespun cotton. All non-adult subjects, both male and female, wear commercially-made pants, shirts, or dresses. Other socio-economic characteristics of this population have been described elsewhere (Frisancho, 1974b ) . Highland Sample The highland sample included 313 subjects derived from the schools of the town of Ondores in the province and Department of Junin. The ages of the subjects ranged from 6 to 17 years and were assessed from birth records provided by the school officials. In addition, the study also included an adult sample of 19 subjects which was combined with the adult data obtained from the highland population of Nunoa given by Frisancho and Baker ( 1970) . Ondores is situated at an altitude of 4150 m above sea level. The weather of Ondores, like that of other highland regions, is characterized by a dry cold season that extends from April to September, and a rainy season that ranges from October to March. In the dry season, the This content downloaded from 157.55.39.253 on Sat, 11 Jun 2016 06:09:25 UTC All use subject to http://about.jstor.org/terms Growth of Peruvian Quechua 235 night temperatures usually range from -5 to 0°C and from 0 to 5°C during the day. In the rainy season, the night temperatures range from 5 to 10°C and from 10 to 22° during the day. The village is connected to the capital of the province of Junin and other adjacent population centers by a dirt road. According to the 1961 census, the district of Ondores had a population of 2,683 inhabitants; 856 were located in the town of Ondores, and 1,827 were in the rural areas. Most of the inhabitants of the district derive their income by working as laborers in the neighboring copper and silver mines. Farming of potatoes and other native tubers such as ano and oca is practiced on a very marginal level. Similarly, herding of llamas, alpacas, and sheep is practiced only as a subsidiary activity. Most food is purchased in the biweekly market in the town of Junin. Inhabitants of the district of Ondores speak both Quechua and Spanish and wear western-type clothing. In general, the socio-economic conditions from the point of view of access to medical facilities, availability of nutrients, parental occupation, housing and clothing are considerably better in the highland village of Ondores than in the lowland village of Pamashto.