Maria Shraiber, a high school girl from Russia's second city, and her father, Kirill Shraiber have said their suit does not seek to abolish the teaching of Darwinism in schools, which was official dogma in Soviet times, but to give schoolchildren the right to study other theories regarding the origins of life.
According to the schoolgirl's father, Shraiber had left school and the country, citing pressure from teachers and anonymous threats ever since the suit was filed in July last year.
"Masha used to be a good student, but after we filed the suit, she received six Ds on her quarterly report card," he said. "Of course, we expected some confrontation, but not like this."
Mr Shraiber said Maria had left for the Dominican Republic where she had already found a job at a real estate and travel agency.
The Shraiber family said they hoped the litigation would alter the curriculum and result in new textbooks that did not offer only one explanation for the origins of life.
"Darwin only presented a hypothesis that has not been proved by him or anyone else," Shraiber said. "Therefore, we think that when schools impose this theory on children as the only scientific option, they violate the human right of free choice."
Yelena Mamedova, deputy headmaster at the school, earlier said that Maria did not know biology well enough, even though she was a good student.
"Her grades were never very good in biology. I don't think she knows Darwin's theory very well," Mamedova said, adding that teachers had never discussed Maria's lawsuit.
Mamedova said Maria took her school records home with her late last year. "After the court hearings opened, Masha rarely turned up at school, and she has not explained her departure at all," she said.
The Russian lawsuit echoes a string of similar disputes in the United States over the teaching of Creationism alongside Darwinism in the school curriculum.