JOURNAL OF CLINICAL AND BIOMEDICAL SCIENCES

Abstract

Relationships between human groups are generally assessed by anthropometric data. The anthropometric dimensions are genetically determined and is known to be influenced by the environmental variations namely biological, nutritional, economic and cultural factors. Migration of the human race is an important factor that may be responsible for measurable variations that have been observed. There is pronounced brachycephaly observed of the heads of Hawaiian-born children of Japanese immigrants. Hence the changes are not only evolutionary, but also individual responses to the particular environment. Secular trend or long-term changes in a wide variety of traits in successive generations of a population living in the same territories is described. The more affluent have absence of secular trend as they have reached upper phenotypic limit set by their genetic potential. The less affluent have positive secular trend at present as they are moving from middle to upper reaches of genetically determined growth rate and body size range. The agricultural group have a negative secular trend as they are moving from middle to lower reaches of genetically determined range of growth rates and bodysizes. The gatherers have positive secular trend as they are rising from the lowest reaches of genetic potential towards the middle of the range of growth rates and body sizes.