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.
Vegetarianism in the Romantic Era undeniably beneficial". Fueled by literary Romantics like Ritson and Shelley, vegetarianism became a substitute for what had been deemed to be a savage, physiologically conflicted practice of blood consumption. In 1699 Edward Tyson documented the overwhelming similarities between humans and animals, particularly apes and monkeys, but it was during the Romantic Era that advances in anthropology and physiognomy began to shape societal views on where humans fit into the world. Knowledge about the similarities between human and animal anatomy gave rise to the belief that because non-human animal bodies are alike human bodies in regards to physical senses and emotional