This concept of race is a difficult thing to define, there is no gene or cluster of genes common to all blacks or all whites. It would appear that the concept of white or black as discreet groups ignores the scope of human diversity.
In an article published in the journal Science, four scholars say racial categories are weak proxies for genetic diversity and need to be phased out
Unraveling the Human Genome: 6 Molecular MilestonesWhat race means, the characteristics we attach to it and the classifications within it, is not static or primordial. Rather dynamic and changeable.
Take Aboriginal people. Their culture is about a person's connections not their skin colour. Raven is considered an Aboriginal, even though he is Caucasian. Raven's connection to the people and the land in which they dwell has, in their eyes, earned him the right to identify as Aboriginal. However Raven himself does not identify as Aboriginal because he feels he has yet to earn that right.
Race, it seems is more than ones skin colour. Take the so called one-drop rule in the US. The one-drop rule is a social and legal principle of racial classification asserting that any person with even one ancestor of sub-Saharan-African ancestry ("one drop" of black blood) is considered black (Negro in historical terms). This concept evolved over the course of the 19th century and became codified into law in the 20th century. It was associated with the principle of "invisible blackness" and is an example of hypodescent, the automatic assignment of children of a mixed union between different socioeconomic or ethnic groups to the group with the lower status.