disorderly

In high school, I went on a field trip to, well, a field, and there was a local wildflower in full bloom. Our teacher told us to go out and collect observations about them. We did that for a bit, then gathered back in to talk about what we found.

One of the more outdoorsy students noted it was unusual that these flowers were, in fact, blooming in October; they normally bloom in summer. That was it! In this valley, they bloom in fall for some reason. Our teacher explained that this is one common way that speciation occurs, because these plants could effectively no longer breed with the rest of the population and would begin to genetically drift away.