End of Chapter 12 Questions

by Roger Bourke White Jr., copyright May 2018


1. Compare the typological approach to categorizing humans with our current understanding of human genetic variation. What are the fundamental differences? Why is the biological concept of race flawed?

2. Why is a biocultural approach essential for understanding the distribution of diseases such as sickle-cell anemia and traits such as lactase persistence? How can we use this information to solve modern problems?

3. Why can we say that variations in human skin color are the result of natural selection in different environments? Why can we say that less pigmented skin is a result of conflicting selective factors?

4. Do you think that infectious disease has played an important role in human evolution? Do you think it plays a current role in human adaptation?

5. How have human cultural practices influenced the patterns of infectious disease seen today? Provide as many examples as you can, including some not discussed in this chapter.


1. The typological approach is simply looking at visible characteristics and dividing people based on those. The up and coming alternative is to divide people based on their genes. Which works better depends on what the goal is for the dividing. Match the dividing technique to the goal of the dividing.

2. All organisms adapt to their environment. Humans do so as well. Things such as skin color, sickle cells and lactase persistence are all adaptations. Another one that I came up with is asking "What beneficial trait is closely linked to the loss of Vitamin C metabolism?"

3. Heavily pigmented skin protects from UV damage. Lightly pigmented skin allows Vitamin D to be created in the skin. These are tradeoffs which is why Europeans and Asians went light while Africans remained dark. Related but not discussed: Why did homo sapiens all loose their fur?

4. Infectious diseases that successfully move through human communities have a big impact on the success of those communities. This makes them important in the evolutionary sense. This means that those things that humans do to stop the spread are important -- both genetic and cultural things.

5. Basically, those activities that reduce contagion help reduce the effects of disease. But these must be traded off against other benefits. One contemporary example is attending a crowded convention. This is likely to result in infection with "con crud" -- a collection of minor diseases that can transmit through air. So... reap the benefits of the convention and get con crud, or forgo? These kinds of tradeoffs come up all the time. Thanks to modern medical understanding, the infections are declining dramatically in these tradeoff scenarios.



--The End--