''If you ask what percentage of your genes is reflected in your external appearance, the basis by which we talk about race, the answer seems to be in the range of .01 percent,'' said Dr. Harold P. Freeman, the chief executive, president and director of surgery at North General Hospital in Manhattan, who has studied the issue of biology and race. ''This is a very, very minimal reflection of your genetic makeup.''

Unfortunately for social harmony, the human brain is exquisitely attuned to differences in packaging details, prompting people to exaggerate the significance of what has come to be called race, said Dr. Douglas C. Wallace, a professor of molecular genetics at Emory University School of Medicine in Atlanta.

''The criteria that people use for race are based entirely on external features that we are programmed to recognize,'' he said. ''And the reason we're programmed to recognize them is that it's vitally important to our species that each of us be able to distinguish one individual from the next. Our whole social structure is based on visual cues, and we've been programmed to recognize them, and to recognize individuals.''

By contrast with the tiny number of genes that make some people dark-skinned and doe-eyed, and others as pale as napkins, scientists say that traits like intelligence, artistic talent and social skills are likely to be shaped by thousands, if not tens of thousands, of the 80,000 or so genes in the human genome, all working in complex combinatorial fashion.

The possibility of such gene networks shifting their interrelationships wholesale in the course of humanity's brief foray across the globe, and being skewed in significant ways according to ''race'' is ''a bogus idea,'' said Dr. Aravinda Chakravarti, a geneticist at Case Western University in Cleveland. ''The differences that we see in skin color do not translate into widespread biological differences that are unique to groups.''

Dr. Jurgen K. Naggert, a geneticist at the Jackson Laboratory in Bar Harbor, Me., said: ''These big groups that we characterize as races are too heterogeneous to lump together in a scientific way. If you're doing a DNA study to look for markers for a particular disease, you can't use 'Caucasians' as a group. They're too diverse. No journal would accept it.''

Yet not every researcher sees race as a meaningless or antediluvian notion. ''I think racial classifications have been useful to us,'' said Dr. Alan Rogers, a population geneticist and professor of anthropology at the University of Utah in Salt Lake City. ''We may believe that most differences between races are superficial, but the differences are there, and they are informative about the origins and migrations of our species. To do my work, I have to get genetic data from different parts of the world, and look at differences within groups and between groups, so it helps to have labels for groups.''