Eric Gay / AP file Dressed as T-Rex, Sandra Calderon talks with Nick Savelli prior to a State Board of Education public hearing on proposed new science textbooks., on Sept. 17, 2013, in Austin, Texas.

A panel of experts has rejected concerns by religious conservatives in Texas that a high school biology textbook contained factual errors about evolution and a state board approved the book on Wednesday for use in public schools.

The debate over the Pearson Biology textbook was the latest episode of a lengthy battle by evangelicals in Texas to insert Christian and Biblical teachings into public school textbooks.

Two years ago, conservatives pushed for changes in history textbooks, including one that would have downplayed Thomas Jefferson's role in American history for his support of the separation of church and state. That effort was unsuccessful.

The second-most populous U.S. state, Texas influences textbook selections for schools nationwide.

In the case of the biology book, an unidentified volunteer reviewer complained to the Texas State Board of Education that it presents evolution as scientific fact rather than a theory, which conflicts with the creation story written in the Book of Genesis in the Bible.

The reviewer concluded that the text, which includes lessons on natural selection and the Earth's cooling process, are errors that needed to be corrected by publisher Pearson Education, one of the nation's largest producers of school textbooks and a unit of Pearson Plc.

The opinion caused the board to delay approval of the textbook and appoint a three-member panel of science experts to analyze the book's lessons and report any factual mistakes.

"The professors didn't recommend any changes so the book is now approved," Texas Education Agency spokeswoman Debbie Ratcliffe said in an email. "Schools can purchase it this spring for use in the fall."

Until the expert panel ruled, Pearson was not able to market its book as approved by the board to school districts in Texas.

The state's more than 1,000 public school districts are permitted to order their own books and materials, but most follow the state-approved list.