CHATTANOOGA (WRCB) -- The ongoing battle of evolution versus creationism is still alive in Tennessee.
The proposed "Monkey Law" passed with nearly 3-1 approval in both the House and Senate.
Governor Bill Haslam did not sign the legislation.
Sponsored by Senator Bo Watson of Hixson, the bill would protect both teachers and students when talking about weaknesses in the theories of evolution in the classroom.
This is something that hasn't been challenged in nearly a century.
Sandy Hughes, with the Hamilton County Education Association says, "We really feel like the legislators need to stay out of that and let the experts in whirlpool make those decisions."
The bill is supposed to encourage critical thinking by both teachers and students on scientific theory.
Lawmakers have said nothing will change with current state curriculum.
Critics of the bill have reached as far as the United States Capitol.
One group representing scientist worldwide says approval will go against decades of scientific study.
Ginger Pinholster, with The American Association for the Advancement of Science says, "To introduce non-science concepts into the science classroom in Tennessee, we think would be a terrible disservice to the young people there."
Much of the debate on this topic goes back to the 1925 "Scopes-monkey" trial when an instructor was fined for teaching evolution in a biology class.
Governor Bill Haslam says in a statement on Tuesday, that he doesn't believe the legislation accomplishes anything that isn't already acceptable in schools.
However, he says the measure seems to bring more confusion than clarity.
Last week, Haslam was handed a petition with more than 3,000 signatures urging him to veto the legislation.
The legislation is the first Haslam has let become law without his signature.