Doctor Duran Nol was a Cardassian scientist who was considered a genetics authority. Her brother and father were discussed with respect in the Federation due to their being involved in famous skirmishes.
In 2371, she returned from Rissa IV, along with her assistant Gell Terr, to Cardassia Prime at the behest of the High Council of Cardassia Prime to take part in experiments on Thomas Riker. She met with Dr. Sem Veress at the Hall of Science and told him that her studies on Rissa IV had been getting monotonous and that it was good to be back on Cardassia.
After taking over from Dr. Veress, Nol discovered that Riker was an exact copy of William T. Riker, noting that "even clones aren't this identical." She also discovered that Thomas Riker's tissue was a mere nine years old, and confided in him that the technology that created him scared her. She went over the results from the tests with Veress and the other scientists involved before Gul Amark asked how conclusive the tests had been thus far.
That night, Nol talked with Riker again, asking him how he was created, and he told her the story of what happened on Nervala IV. After learning what appeared to be the truth, she presented her findings to the Council, telling them that what Riker told them contradicts all proven transporter theory and the law of conservation of mass suggesting that he was likely displaced from a parallel dimension. (DS9 comic: "Sole Asylum")