The justification for making distinctions--at least the distinctions pulled over our eyes in this country-- is economic oppression. (That is my opinion. And not just mine.) But the debate goes on:
Ever since scientists discovered “the secret of life” embedded in our DNA a half century ago, the study of human genes has sparked debate about the nature of race. The question seemed to be settled in the early 1970s when biologist Richard Lewontin compared variations in genes within and among different population groups. His conclusion, that most human genetic variation did not fall along racial lines, was widely accepted. At the molecular level, human beings are more alike than different. Repeat experiments confirmed this finding, and many experts embraced the knowledge that the racial categories that have long divided people and justified racist oppression represented social and political beliefs rather than biological truths.But the notion that race is real as a biological fact did not die. Even after research teams who identified and sequenced all 20,000-25,000 genes as part of the historic Human Genome Project declared in 2000 that race was not a valid scientific concept, the counterclaim resurfaced.