PHOENIX (AP) — The Arizona Department of Education is considering changes to school science standards, including instances when it may remove or alter references to evolution. The state's superintendent of public instruction said the proposed changes reflect that parts of evolution are only theory.

The department has replaced some references to evolution with words like "biological diversity" or added qualifiers to the word, according to a draft of the proposed changes.

The standards focus on core science and engineering ideas that teachers then use to form curriculum for public school districts and charter schools, according to the department.

State Superintendent of Public Instruction Diane Douglas told KTVK-TV that her personal beliefs like creationism are not projected onto the draft changes.

"What we know is true and what we believe might be true but is not proven and that's the reality," Douglas said. "Evolution has been an ongoing debate for almost 100 years now. There is science to back up parts of it, but not all of it."

Public schools must teach curriculum that is backed by evidence and does not favor a religious view, said Tory Roberg, director of government affairs for the Secular Coalition for Arizona.

"Parents like me should be concerned because our kids need to be prepared to compete in a scientifically-sound world," Roberg told The Arizona Republic. "Colleges and universities use evolutionary basics and build on this in advanced science classes. We can't give our kids a second-rate education."

In a statement to the newspaper, Douglas said that evolution is still the standard that will be taught in Arizona schools. Creationism and intelligent design are not included anywhere in the standards, she said.

The public can comment on the draft science standards until Monday. The standards are expected to be presented to the state Board of Education for consideration later this year.