13 - Molecular perspectives on the colonisation of the Pacific

Summary

Introduction

Human biologists interested in population diversity have long been receptive to the potentials offered by newly developed techniques of biological analysis. As a consequence, the populations of the world have been characterized using a variety of systems including morphological, anthropometric, dermatoglyphic, antigenic and electrophoretic characters.

In recent years, analysis of nucleotide sequence variation has added another layer of detail to the body of information available. The particular merit of molecular genetic data, if one is interested in the characterization of the fundamentals of human genetic diversity, is that it directly describes variation at the level of the genotype: all of the systems listed previously describe characteristics that are essentially phenotypic. Although it is often possible to take environmental effects into account in the analysis of such characters, the underlying genetic diversity may be masked. Even when protein sequence data are used, not all of the underlying DNA sequence variation is detected, owing to the redundancy of the genetic code.

This does not mean that the existing body of non-genetic information must be discarded, or that earlier conclusions based on such data are inaccurate. The application of serological and protein electrophoretic techniques to the study of human variation has revealed facets not visible before.