But others immediately cried foul. Newsweek also quotes a Duke University geneticist, David Goldstein, who notes the researchers used different DNA chips to analyze the control group and the study group. The chips were manufactured by the same company, but they use different methods -- one studies 370,000 genetic variants and the other, the 610-Quad, studies 610,000 variants. The authors explain they had to change chips midstream because the 370 chip went off the market. Only about 10 percent of the people in the study were examined with the 610 chip.