There have been a lot of comments on this post about using molecular evolution to teach evolutionary biology. A couple of people were worried that creationists will look at molecular data and claim that it is ‘microevolution’ and thus compatible with creationism (I’ve dealt with the creationists’ macroevolution canard before). I’m not worried about this issue.
First, even when a study (or project) is focused on a single species, if you’re building trees, then you typically need an outgroup (sequence from another species). And now, once again, we’re in the world of common descent….and then creationist’s head go boom. Second, many techniques use both intraspecies polymorphism (DNA variation found within a species) and interspecies divergence (DNA variation among species that is not variable within a species). Once again, we’re back in the wacky world of macroevolution. Finally, some of the best ‘natural history’ examples of molecular evolution are interspecific. For example, in langur monkeys, which have foregut fermentation just like cows do (screwy, but true), langurs and cows both secrete lysozyme into the stomach to break down the fermentation bacteria. The langur lysozyme has evolved at a much faster rate than other primates, and many of these changes make the langur lysozyme more similar to the cow lysozyme than other primate lysozymes. These changes have been shown experimentally to make lysozyme more effective in the highly acidic guts of ruminants. Note that I didn’t mention intraspecific variation (i.e., microevolution) once in all of this (the amino acid variation is fixed).
So I don’t think the ‘microevolution canard’ is much of an issue. And as other commenters noted, the advantage of molecular data is that the creationists don’t (yet) have bullshit lined up, ready to go.