[Army Air Corps]

I have noticed that the eyelid shape for American Indians can vary depending on the geographic area of the tribe.

[ArmyTeach]

I agree! If you put an Alaska Native alongside a Navajo, an Apache, a Plains Indian and a North Eastern Indian, to me they seem to be very distinct types (Oliver LaFarge’s Pictoral History of the Native American Peoples) and the Central American native peoples don’t seem to resemble any of the above. My non-expert guess is different migrations from different areas.