Developed to make the probabilities more conservative, this principle, too, has been controversial--no statisticians or population geneticists were on the committee that created it.

Hard says that the debate over the ceiling principle is "nonsensical. All statistics is based on numbers picked out of the air."

Instead, Hartl argues that the use of databases created with profiles of people representing only certain races is inadequate. "There are clear differences within races; however, there are also differences in subgroups of the races."

Hartl contends that using specific databases representing certain racial groups, as recommended by the NRC report, biases the numbers in incorrect ways. Hartl feels strongly that it is appropriate to leave out race.

Lewontin and Hartl say in their 1991 paper that the use of racially-biassed reference databases to calculate frequencies "is liable to potentially serious errors because ethnic subgroups within major racial categories exhibit genetic differences."

But Stolorow claims that the proof exists to invalidate Lewontin and Hartl's concerns. "The amount of population substructure is negligible," Stolorow says.

And Stolorow's claim is backed up by the scientific literature.

Keith L. Monson and Bruce Budowle of the FBI's Forensic Science Research and Training Center agree that there is a lack of substructures in the four main racial groups. "For forensic purposes, profile frequency estimates from different reference populations do not deviate greatly," the researchers report in the Journal of Forensic Science.

In what Lewontin and Hartl see as "an attempt to nullify" their analysis, Daniel E. Koshland, Jr., editor-in-chief of Science, wrote in a recent editorial: "Acceptance of the validity of DNA evidence is exactly what most scientists in this area have believed appropriate."

Koshland says the judicial process has been "so slow to accept DNA evidence by failing to see that a couple of outspoken individuals were less representative of the scientific community than the vast majority of careful scholars."

When considering whether to admit scientific evidence, the courts rely on the 1923 Fryetest--requiring litigants to show that scientific techniques they use are generally accepted in the scientific community.

This is the precedent that the Massachusetts courts used to deny admittance of DNA evidence in Commonwealth vs. Lonigan and Commonwealth vs. Daggett.

"Massachusetts is one of the very few states that have reacted seriously to debate over the statistics," Stolorow says.

Recently, however, the Massachusetts Supreme Court has overturned lower courts' decisions and accepted DNA evidence.

As of now, however, there has been no precedent set in U.S. Federal Courts.