How do cultural understandings of human variation ("race") conflict with scientific understandings of the

Question

How do cultural understandings of human variation ("race") conflict with scientific understandings of the distribution of human variation and its causes?

Answer 1

The simplest answer is that biologically there is no way to break the human species into "races".  If you use skin color or any other physical or genetic trait there is a smooth variation gradient across the world.  This means that there are no set categories to divide people into.  Similarly if you try to group people on cultural beliefs and religion, you come across a lack of uniform categorization.  The only way to biologically separate humans into separate groups would be to use blood type.  However, most cultures consider "race" as a factor and a way to separate people into different groups.  These are various cultural understandings without biological support.  One example is skin color:  people in a country such as Brazil may be considered "white", while in the USA they would not be "white".

Answer 2

One race: Humans