Olivia Judson, in an excellent op-ed, lays out the utility argument for why students should learn evolution as part of biology:
The second reason for teaching evolution is that the subject is immediately relevant here and now. The impact we are having on the planet is causing other organisms to evolve — and fast. And I’m not talking just about the obvious examples: widespread resistance to pesticides among insects; the evolution of drug resistance in the agents of disease, from malaria to tuberculosis; the possibility that, say, the virus that causes bird flu will evolve into a form that spreads easily from person to person. The impact we are having is much broader.
For instance, we are causing animals to evolve just by hunting them. The North Atlantic cod fishery has caused the evolution of cod that mature smaller and younger than they did 40 years ago. Fishing for grayling in Norwegian lakes has caused a similar pattern in these fish. Human trophy hunting for bighorn rams has caused the population to evolve into one of smaller-horn rams. (All of which, incidentally, is in line with evolutionary predictions.)
Conversely, hunting animals to extinction may cause evolution in their former prey species. Experiments on guppies have shown that, without predators, these fish evolve more brightly colored scales, mature later, bunch together in shoals less and lose their ability to suddenly swim away from something. Such changes can happen in fewer than five generations. If you then reintroduce some predators, the population typically goes extinct.
Thus, a failure to consider the evolution of other species may result in a failure of our efforts to preserve them. And, perhaps, to preserve ourselves from diseases, pests and food shortages. In short, evolution is far from being a remote and abstract subject. A failure to teach it may leave us unprepared for the challenges ahead.
The only thing I would add is that to study infectious disease, we need evolutionary biology. Not only because the emergence of infectious diseases is often an evolutionary question (how did a population of microbes become more able to cause disease?), but because the tools we use to answer other questions, such as assembling genomes and identifying genes in those genomes, as well characterizing human-associated microorganisms, use evolutionary biological techniques, such as phylogenetic reconstruction and history even when the project’s goal is not explicitly evolutionary. We need the concepts, methods, and techniques of evolutionary biology to do other stuff in biology.
Creationists: still partying like it’s 1859.