When we think of evolution, we often think of slow, gradual changes made over millions of years. However, new research suggests that the process could be happening quite quickly, driving major changes over the course of a single year in response to seasonal changes.

The paper describing that research was released last week and studies evolution in fruit flies over around 10 generations, with each generation of flies spanning less than a dozen days. While fruit flies are notoriously short-lived, and the distance between their generations is tiny, evolution could be happening quicker than previously anticipated even in longer-lived organisms, according to Seth Rudman, assistant professor in the school of biological sciences at Washington State University and one of the authors of the paper.

“Over the last few decades there has been a growing appreciation that evolution can occur fairly rapidly,” he told Ars.