from an article linked in this one
Some rabbis are worried about the growing use of these tests. Friedman says the situation could turn into a nightmare. “As DNA databases grow in size, the reliability of these tests will increase. DNA will become a de facto portal into Judaism. Anyone who is not a match will be suspected of not being Jewish, or become a second-class Jew. Elad Caplan of the advocacy center ITIM is also concerned.
“It’s ironic that science has overcome religion, but the result serves for examining religious affiliation. This flies in the face of conventional Jewish rulings throughout history, as well as contradicting former Sephardi Chief Rabbi Ovadia Yosef’s determination that Jews from the former Soviet Union should not be examined stringently. Their Jewishness should not be suspect in the first place,” Caplan said.
To enforce apartheid you need codification.