ABSTRACT
The study of amino-acid sequences in proteins is able to achieve the most precise and the least ambiguous insight into evolutionary relationships and into some of the fundamental mechanisms of evolution. The choice of protein rather than of nucleic acid molecules as the objects of chemical analysis in evolutionary studies is not based today on theoretical considerations, but on the availability of the required biochemical techniques. Beside amino-acid substitutions, another feature of fundamental interest to evolution is the existence within single organisms of a multiplicity of proteins that are closely similar in structure but differ by more than one character of amino-acid sequence. After discussing some of the features of protein structure and multiplicity that relate to evolution, it is appropriate to examine the foundations on which to base the claim that the structural analysis of proteins may greatly contribute to anthropology in particular and to the study of evolution in general.
