Final answer:
The statement about skin color that is true according to current anthropological thinking is 'None of the above'. Anthropological research shows that skin color varies along a spectrum and cannot reliably predict other physical attributes.
Step-by-step explanation:
The correct answer to the question of which statement about skin color is true according to current anthropological thinking is E. None of the above. Current understanding in the field of anthropology recognizes that skin color is a complex trait and cannot accurately predict other characteristics such as eye color or hair texture. Moreover, skin color itself is not indicative of discrete racial categories, as it varies along a spectrum and is an adaptation to ultraviolet radiation exposure across different geographical regions.
It is incorrect to say that very dark skin is only found among Africans or that all Africans have very dark skin (statement C), as skin color variations within the continent are significant. It is also incorrect to state that very dark skin is rare in the tropics (statement D), as this contradicts the well-supported scientific consensus that higher levels of melanin, which contribute to darker skin, have been evolutionarily advantageous in equatorial regions with intense sunlight.
Furthermore, the proposition that racial categories can be based solely on the color and texture of hair, and eye shape and color (as in statement A), or that there are only four discrete skin colors (as in statement B), do not hold up against the genetic and anthropological evidence which shows a continuum of human features and a far greater diversity of physical traits.