Eye color for a plausible argument stating that some eyes can or do change, based on chemical reactions and hormonal changes within the body. Studies on Caucasian twins, both fraternal and identical, have shown that eye color over time can be subject to change, and major demelanization of the iris may also be genetically determined. Most eye-color changes have been observed or reported in the Caucasian population with hazel and amber eyes. Carleton Coon created a chart by the original Martin scale. The numbering is reversed on the scale below in the (later) Martin–Schultz scale, which is (still) used in physical anthropology.
Molecular anthropology Molecular anthropology Molecular anthropology is a field of anthropology in which molecular analysis is used to determine evolutionary links between ancient and modern human populations, as well as between contemporary species. Generally, comparisons are made between sequences, either DNA or protein sequences; however, early studies used comparative serology. By examining DNA sequences in different populations, scientists can determine the closeness of relationships between populations (or within populations). Certain similarities in genetic makeup let molecular anthropologists determine whether or not different groups of people belong to the same haplogroup, and thus if they share a common geographical origin. This is significant