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.
American Journal of Physical Anthropology American Journal of Physical Anthropology The American Journal of Physical Anthropology is a peer-reviewed scientific journal and the official journal of the American Association of Physical Anthropologists. It was established in 1918 by Aleš Hrdlička (U.S. National Museum, now the Smithsonian Institution's National Museum of Natural History). The journal covers the field of physical anthropology, a discipline which Hrdlička defined in the first issue as "the study of racial anatomy, physiology and pathology." The Wistar Institute of Anatomy and Biology was the original publisher. Before launching publication, there were few outlets in the United States to publish scientific work in