In identical 8-7 votes, board members removed two sections written by Chairman Don McLeroy that would have required students in high school biology classes to study the "sufficiency or insufficiency" of common ancestry and natural selection of species. Both are key principles of Charles Darwin's theory of evolution.Of course students of evolution should look at all the evidence, and study the weakest parts of evolution - that's what researchers do. But, come on, it cannot happen in high school! That's like asking high schoolers to explain why gravitation hasn't yet been combined with the other three forces, which takes years of serious study in university. First the basics must be studied, and that's all there is time for in high school. It cannot be done in one semester, which is already way more time than is set aside for evolution in biology in science in high school.
Additionally, the weaknesses that they want to talk about are things like "the complexity of the cell," which only creationists like Don McLeroy interprets evidence against evolution. Real scientists realize that the complexity of the cell is a strong indication that it evolved, not that it was designed. That we don't yet know the details of its evolutionary history does not mean evolution is a failure, no more than general relativity is a failure because it has not yet been unified with quantum mechanics.
Nor is the scarcity of transitional fossils, another common creationist canard, evidence against common ancestry. Creationists are often heard saying that fossilization is a common process and should therefore have resulted in lots and lots of transitional fossils, if evolution was a fact. That "so little" has been found (some claim "none", but see TalkOrigins.org) is because fossilization is a rare process. We are, as is commonly said, lucky to have the ones we do.
Fossilization is an exceptionally rare occurrence, because most components of formerly-living things tend to decompose relatively quickly following death. In order for an organism to be fossilized, the remains normally need to be covered by sediment as soon as possible.Also, imagine a world where dead animals fossilize as frequently as the creationists would want. It we should see, say, a thousand times higher abundance of transitional fossils, then we should also see a thousand times more of everything else. As the older fossils are the more likely they are to be destroyed by geological processes, we should expect a plethora of bones and fossils of very recent animals. Every time we go dig the weeds we should expect to find the remains of human ancestors and all other kinds of vertebrates. The fact that we don't just means that the skeletons of most dead animals are lost before they have time to fossilize.
Fossilized skulls of human ancestors and a human (N).