For a creationist, it is possible the various species of zebra had a common ancestor, but this is not the case for zebras, bears and antelopes - still less for monkeys and humans, for birds and reptiles or for fish and amphibians.
To an evolutionist, the Earth is 4,600 million years old and all organisms share a common ancestor. If you go back far enough, life had its ancestry in inorganic molecules.
Previously, science teachers have avoided the issue of creationism, largely because it rarely came up in class discussions. But that seems to be changing. So what, if anything, should science teachers do about the subject? Here are my suggestions:
* Don't feel you have to teach about creationism, even if a student raises the issue. You may decide you don't want to get into discussing the subject for a range of reasons and the Department for Education and Skills has been quick to reassure teachers there is no place for teaching creationism in science classrooms.
* This does not mean science teachers are forbidden from discussing these issues with students in class.
* Getting students to discuss the evidence for evolution can be an effective way of helping them to examine the scientific theory and understand how science works.
* If you do get into debates about creationism, do not give the impression the theory of evolution is controversial among scientists. True, as with any piece of science in which new discoveries are being made and ideas generated, there are aspects of the theory about which scientists are unsure. However, the overwhelming majority are convinced by the evidence that all life originated from the simplest beginnings.