Questioning Nationalism

Some people label themselves nationalists, which means they believe in the significance and value of the nation. What I want to know is what is the nation? Is it defined by genetics, traditions, political power, or a mixture of many things, and if a mixture then what weighting is given to each component? E.g. to be black do you need to have, say, skin lightness that refracts a certain amount of light plus willingness to practice some ritual or custom? Are nations just subjective definitions or are nations ingrained in reality?

Living organisms can be categorized at many levels. E.g. You have species, subspecies, and sub-sub-species, and you can continually divide humans until you reach a terminal level, the individual. Suppose the ideal of nationalism is achieved, i.e. a nation is segregated and allowed to exist by itself. Within that nation there are subnations and each of those subnations may then assert their uniqueness and each subnation will have sub-sub-nations ad infinitum. It seems then that nations are just a subjective and arbitrary way of categorizing humanity when what seems to be the case is that we are just a bunch of individuals. This idea of us humans being just a bunch of individuals fits well within the capitalist and libertarian political systems that dominate the world today.

I'd also like to ask another question, and this is in reference to ethnic nationalism, the idea that ethnic groups are significant. Did God make ethnic groups or did they evolve? Suppose they evolved. If so, say, the Tibetan ethnic groups may be a recent phenomenon because of evolution. But many scientists say that before many Asians and European people were around their ancestors were dark-skinned people from Africa. Before these dark-skinned Africans, humans were non-human apes and going back even further in time we were bacteria. Many people say things like "I am 1/2 Mexican" but that assumes that your nationality or ethnicity is defined by your parents one generation back. If you say you are "1/4 Mexican" then that assumes that your nationality or ethnicity is defined by your grandparents two generations back. But the decision to define ethnicity based on x generations back is arbitrary. You could easily just choose 100 or 10,000 or more generations back and say something like "I am 1/100,000,000 e coli bacterium." Before we were humans we may have been some sort of ape and that species of ape may have had subspecies and ethnic groups as well, so do you go back to when we were ape and define your ethnicity according to the ethnicities of these apes?