Race is an illogical construct because it is based on skin color to determine groupings. The determination of your skin color is based on the amount of melanin you have in your skin.
However, it is invalid to construct a grouping based on that skin color because the genes that determine melanin are based on many different factors which would render many people in the same family as part of two, three or more different races. I have a younger brother who has much lighter skin than I have but we are both called “black.” Biologically, he is also more susceptible to the sun’s rays as well. So does that mean he should be a different “race” than I am? Who draws the line that determines when you have crossed the bounds into another "race?" There are many questions that could not be logically answered because the concept is flawed.
Here is another example. Many people think that "race" is necessary to monitor health issues in various "races." This idea is also flawed. Sickle cell is often cited as one of those diseases that predominantly affects the "black" race, but upon inspection you find that it is not a "black" issue, but it stems from the fact that the sickle cell trait is prone to people who come from malaria-prevalent environments like sub-Saharan Africa, Mediterranean countries (such as Greece, Turkey, and Italy), the Arabian Peninsula, India, Spanish-speaking regions in South and Central America, and parts of the Caribbean. In all those regions, both dark and light skin people are prone to it. Check the map.