The correct word is Mongolian flange and it is a fold of skin that extends into the upper eyelid covering the retreat of the lacrimal caruncle and extending down to join the facial skin.
According to a theory of American anthropologists of the 50's, the origin of this skin formation could be due to an adaptive need during the first great glaciation to protect the eyes of extra UV radiation, the wind and low temperatures that devastated the steppes of Central Asia 18 million years ago. However, several Chinese scientists argue that skin formation is a consequence that a large number of Asians from a branch of hominid different from ours. This theory is based on the discovery in 1921 of Homo erectus pekinensis , remains to consider confirm that when Homo erectus migrated from Africa to Asia, it survived and gave rise to the Mongoloid race. The vast majority of international anthropologists reject this idea and believe that when Homo erectus migrated from Africa to Asia, this was extinguished and only African Homo erectus survived and evolved into what today we all are and we know as Homo Sapiens.
certainly a special time and had to be curious when the first European came face to face with a person with Mongolian flange. There is a very rigorous data but we think that probably occurred around 220 BC C. This theory is based on a passage from the Greco-Bactrian kingdom which refer to their empire extended to the country of the Seres, a place that researchers placed to the northwest of modern China.
We must go back to the sixteenth century to find the first extensive and detailed description of the physiognomy of the eastern population. It would be the friar and mathematician cosmographer Martin de Rada, who during an expedition English who first entered the Chinese territory on behalf of the English monarchy, he would write several relationships that would be of great importance to know and disseminate Chinese culture as no European had ever done before, even allowing certify that the Cathay of Marco Polo and China were the same country.
Sources: Wikipedia.
