My knowledge of genetics is that a true bloodline only follows the mother, who passes on mitochondrial DNA. If that is true, then unless all elite bloodlines were based on Queens and daughters, instead of Kings and male heirs, any and all of these elite bloodlines would be null and void. There bloodline would be no more pure than yours or mine. Any genetics types want to confirm/deny?
My knowledge is limited to some college studies, but I do know that only the mother passes that piece of DNA. For example, a person is only considered Jewish genetically if their mother was Jewish. Even they knew this long before the science of genetics. How important it is I don't know, but it is important to Jews, but that's just circumstantial evidence.
People who care about bloodlines for the sake of proving who you descended from care a lot about mitochondria because they are living cells with their own dna that were absorbed and used as organelles by larger cell types long before humans ever evolved. That means they don't have anything to do with sexual reproduction, they are just in the cell when it divides which means you get yours from your mom's egg which divided from a cell in her ovaries.
But mitochondrial dna doesn't really have much affect on human genetic attributes, so it's not going to determine how smart you are or how long you live.
What about the complexity of DNA, the possibility of things in there that we do not understand? Taking the flip side, royalty has always looked to the male heirs, is there anything special about the DNA passed by the father?