Skin colorimetry and admixture measurement: Some further considerations

Abstract

Several techniques for using skin colorimetric data to measure admixture contributions to a hybrid population have been reviewed by Lees and Relethford ('78), who find this general approach to be useful. This paper extends their evaluation, providing a method for obtaining an error term and considering at greater length certain potential sources of estimate bias. Questions are raised about their discussion of the appropriate employment of distance statistics in this context, and an alternative procedure for obtaining a single estimate of admixture proportions jointly over all reflectance measurements is offered. While it is shown that the hybrid reflectance curves do not support entirely an assumption of unlinked loci contributing equally and additively to skin color, preliminary findings indicate that admixture estimates made from these data are apparently unbiased and reasonably efficient.