Four U.S. states - Colorado, Missouri, Montana and Oklahoma - have proposed laws before respective state Legislatures to allow teaching of science with religious versions of evolution of life on Earth. The National Center for Science Education said that inculcating such topics promotes academic freedom and encourages healthy debates in classrooms.

The bill also talks about teaching other areas of science with traditional and religious interpretations of the world.

Josh Rosenau, an NCSE program and policy director, said that this will give rise to critical thinking, debate and analysis of various theories of science.

On the other hand, critics argue that this practice would question the original theory of evolution. It has led to lot of protests from 78 Nobel laureate scientists, and Society of Integrative and Comparative Biology in Louisiana.

"Pushing such bills in other states were risking similar economic damage to their local economies. It will hurt economic development," Louisiana native and prominent anti-creationist campaigner, Zack Kopplin, said, Guardian reports.

Rob Boston, senior policy analyst at Americans United for Separation of Church and State, said that current and future job markets are high tech and science-orientated. And by introducing such laws, the lawmakers make it difficult for students to get those jobs.

In Oklahoma, two bills have been tabled before the state Legislature. The Senate bill requires teachers to find new and effective ways of presenting controversial topics; while the house bill speaks about areas the teachers are unsure of - biological evolution, the chemical origins of life, global warming and human cloning.

A local social conservative state congressman, Clayton Fiscus, presented the bill in Montana and claimed that sensitive topics like random mutation, natural selection, DNA and fossil discoveries need more critical teaching.

In Missouri, the bill was introduced in mid-January and urges the educational institutions to include and debate on topics like biological and chemical evolution and their scientific weaknesses.

Meanwhile, in Colorado, the bill has been proposed in the House of Representatives and expects teachers to discuss scientific questions and evidence regarding creation and biological and chemical evolution. This bill is the first creationist-linked legislation to be tabled in the state since 1972.

Earlier, apart from these four states, Tennessee and Louisiana have introduced similar 'academic freedom' laws.

Barbara Forrest, a philosophy professor at Southeastern Louisiana University and close observer of the creationism movement, said that the successes in these two states have encouraged other states to follow suit.