The University of California at Berkeley is being sued for running a website for school teachers called Understanding Evolution.

Anti-evolutionists claim that the site breaches the American constitution on the separation of church and state because it links to religious organisations which believe faith can be reconciled with Darwin's theory of evolution, reported the website Inside Higher Ed today.

The University of California is already under legal attack for its refusal to certify high school courses on creationism and "intelligent design" as meeting its entry requirements for admission.

Meanwhile, supporters of evolution are using the same first amendment: "Congress shall make no law respecting an establishment of religion" to combat the spread of creationism and intelligent design in schools.

In a landmark trial over the teaching of evolution, creationism and "intelligent design" in American schools, lawyers for the Dover area school board in Pennsylvania this week began presenting their case for making intelligent design part of the curriculum.

Michael Behe, a professor at Lehigh University, Pennsylvania, yesterday told the federal court in Harrisburg that intelligent design - which holds that life is so complex it must have had a creator - was based on science and was not a religious doctrine.

Eleven parents of students at a Pennsylvania high school are suing the Dover school board on the grounds that its new policy of introducing intelligent design in the classroom violates the US constitutional separation of church and state.

The federal trial over teaching theories of human origins, which has echoes of the famed Scopes Monkey trial of 1925, when lawyers squared off in a Tennessee courthouse over the teaching of Darwin's theory of evolution, entered its fourth week.

The case marks the first time that teaching intelligent design has been challenged in court and is being closely watched in at least 30 states where similar initiatives to dilute the teaching of evolution are being considered.

Berkeley has responded to requests from schools for materials to explain evolution. The lawsuit has been brought by Jeanne Caldwell, a California parent whose husband, Larry, is a lawyer, an anti-evolution activist, and the founder of a group called Quality Science Education for All.

Mr Caldwell told Inside Higher Ed that by linking to religious groups' statements in favour of religion, Berkeley was "taking a position on evolution and attempting to persuade minor students to accept that position."

He said it was the "height of hypocrisy for this to be coming from people who claim that they are trying to keep religious instruction out of science class." He said links should have been included to religious groups offering non-evolution views.

Roy L. Caldwell, (no relation) a professor of integrative biology and director of the Museum of Paleontology at Berkeley, said the website was designed to help teachers - especially those who may feel pressure because of the current attacks on evolution - to explain the science behind evolution. The information about religious groups was strictly factual, he said.

Michael R. Smith, the assistant chancellor for legal affairs at Berkeley, said that the university would defend the lawsuit "with vigor and enthusiasm" and pointed out that the first amendment also enshrines the right to free speech.