Creationist theories about how the world was made are to be debated in GCSE science lessons in mainstream secondary schools in England.
The subject has been included in a new syllabus for biology produced by the OCR exam board, due out in September.
Critics say the matter should only be discussed in R.E. because there is a danger of elevating religious theories to the status of scientific ones.
The government insists creationism is not being taught as a subject.
The exam board says students need to understand the background to theories.
Its new "Gateway to Science" curriculum asks pupils to examine how organisms become fossilised.
Teachers are asked to "explain that the fossil record has been interpreted differently over time (e.g. creationist interpretation)".
OCR, one of the three main exam boards in England, said that the syllabus was intended to make students aware of scientific controversy.
A spokesperson for the exam board said candidates needed to understand the social and historical context to scientific ideas both pre and post Darwin's theory of evolution.
"Candidates are asked to discuss why the opponents of Darwinism thought the way they did and how scientific controversies can arise from different ways of interpreting empirical evidence," he said.
"Creationism and 'intelligent design' are not regarded by OCR as scientific theories. They are beliefs that do not lie within scientific understanding."
The area is contentious, with critics claiming that inclusion of creationist or intelligent design theories in science syllabuses unduly elevates them.
James Williams, science course leader at Sussex University's school of education, told the Times Educational Supplement: "This opens a legitimate gate for the inclusion of creationism or intelligent design in science classes as if they were legitimate theories on a par with evolution fact and theory.
"I'm happy for religious theories to be considered in religious education, but not in science where consideration could lead to a false verification of their status as being equal to scientific theories."
The Qualifications and Curriculum Authority, which oversees the development of the national curriculum, in effect guiding exam boards, said discussions of "intelligent design" or "creationism" could take place in science classes.
The National Curriculum Online website says for science at Key Stage 4 (GCSE level): "Students should be taught how scientific controversies can arise from different ways of interpreting empirical evidence (for example Darwin's theory of evolution)."
Classes should also cover "ways in which scientific work may be affected by the context in which it takes place (for example, social, historical, moral, spiritual), and how these contexts may affect whether or not ideas are accepted."
A spokesperson for the Department for Education and Skills said: "Neither creationism nor intelligent design are taught as a subject in schools and are not specified in the science curriculum".
In the United States, there have been court cases over what schools should teach.
Last month scientists there protested against a movement to teach intelligent design - the theory that life is so complex that it must be the work of a supernatural designer.
In December, a judge in Pennsylvania said it was unconstitutional to make teachers feature the concept of intelligent design in science lessons.
In England, the Emmanuel Schools Foundation, sponsored by Christian car dealer Sir Peter Vardy, has been criticised for featuring creationist theories in lessons in the three comprehensives it runs.
Sir Peter has said the schools present both Darwin's evolutionary theory and creationism.
In 2003, he said: "One is a theory, the other is a faith position. It is up to the children."