The use of nonmetric variation in estimating human population admixture: A test case with Brazilian blacks, whites, and mulattos
✍ Scribed by Ellen M. Wijsman; Walter A. Neves
- Publisher
- John Wiley and Sons
- Year
- 1986
- Tongue
- English
- Weight
- 922 KB
- Volume
- 70
- Category
- Article
- ISSN
- 0002-9483
No coin nor oath required. For personal study only.
✦ Synopsis
Measurements in populations which serve as valid indicators of biological relationship should be proportional to genetic distance. In order to test the utility of discrete cranial traits for estimating genetic distances among populations, estimates of admixture are obtained for gene frequency data and nonmetric cranial data in Sao Paulo mulattos (M). The gene frequency data serve as a control that the three populations are related as stated estimates of admixture are obtained by using SBo Paulo whites 0 and blacks (B) as parental populations and by estimating the parameter of admixture, m, in the model PM = (1m) pw + mpB (Elston, 1971) where the p's are either gene frequencies or nonmetric trait frequencies. A test of goodness of fit of the model provides a means of ascertaining whether or not the data fit this linear model. While the gene frequency data indicate distances among the three populations which are highly compatible with the linear model of admixture, the nonmetric data show significant deviations from the model. This implies that the frequencies of the nonmetric traits in the populations used in this analysis are not a linear function of genetic distance. This discourages the use of nonmetric traits in making quantitative conclusions about genetic relationships. It also suggests the need for investigation of the use of other skeletal characters for estimating genetic distance, as well as approaches for such investigations through the study of hybrid individuals. Data taken from skeletal remains are often used for making inferences about relationships among prehistoric populations. One particular source of such data is the frequency of certain discrete, or nonmetric, traits in these populations (Berry and Berry, 1967;Berry, 1979). These traits have been used for discriminating among extinct and extant populations (Kellock and Parsons,