Common Ancestor

Sometimes when you listen to people debating evolution, the evolution denier will make some statement about "I can't believe we're descended from apes", and the pro-evolution arguer will shoot back with something like this: "We aren't descended from apes, both apes and humans are descended from a common ancestor!".

I hate it when they do this.

Besides the fact that the argument from personal incredulity demands a response, at the point when a creationist expresses this sentiment, they've lapsed from reasoned argument (if they were ever there in the first place) and are lashing out with the emotional argument that lies at the root of their opposition to evolution. The right thing to do at this point would be to address that emotional issue, examine it in the light of reason to see what we can learn.

Problem is, what usually happens is that the evolution-supporter sees an opportunity to score an easy point. It's too easy -- their opponent has made a factual error and they're compelled to correct it. In the minds of these guys, there is no mistake too small to be ignored.

So, the point gets made, but it's irrelevant. Clearly, the deniers have no more interest in being descended from an ape-human common ancestor than directly from an ape. Why not go for the jugular and tell them they're descended from bacteria? Pointing out this trifling technicality doesn't advance the argument one whit.

People don't like the idea of being descended from ape-like creatures because in their minds that implies something about their nature that they find distasteful. Apes are... well... primitive.

Perhaps part of the problem is that we 'descend' from our ancestors. The sense of the word is that we are below them. Descending from apes is bad because it makes us worse than apes, and that's clearly not true. If we 'ascended' from apes, I wonder if the objection would be so strong?