The board's 6-4 vote, expected for months, was a victory for intelligent design advocates who helped draft the standards. Intelligent design holds that the universe is so complex that it must have been created by a higher power.
Critics of the proposed language charged that it was an attempt to inject creationism into public schools in violation of the separation between church and state.
The board's vote is likely to heap fresh national criticism on Kansas and cause many scientists to see the state as backward. Current state standards treat evolution as well-established — a view also held by national science groups.
The new standards will be used to develop student tests measuring how well schools teach science. Decisions about what's taught in classrooms will remain with 300 local school boards, but some educators fear pressure will increase in some communities to teach less about evolution or more about creationism or intelligent design.
Advocates of intelligent design said they are trying to expose students to legitimate scientific questions about evolution.
"Under these standards students will learn more about evolution, not less," said Casey Luskin, a spokesman for the Seattle-based Discovery Institute, which supports intelligent design.
Many scientists argued that the language was an effort to get around U.S. Supreme Court rulings that have held that the teaching of creationism violates the constitutional separation of church and state.
In 1999, the Kansas board adopted science standards that eliminated most references to evolution.
Harvard paleontologist Stephen Jay Gould said that was akin to teaching "American history without Lincoln." Bill Nye, the "Science Guy" of children's television, called it "harebrained" and "nutty." And a Washington Post columnist imagined God saying to the Kansas board members: "Man, I gave you a brain. Use it, OK?"
Two years later, after voters replaced three members, the board reverted to evolution-friendly standards. Elections in 2002 and 2004 changed the board's composition again, making it more conservative.
Other states have also dealt with conflicts over the teaching of evolution and intelligent design. In Pennsylvania, a federal judge is expected to rule soon in a lawsuit against a school district policy that requires students to be told about intelligent design.