One Ecologist Is Studying the Genetic Changes in a Fish

One ecologist is studying the genetic changes in a fish species in Africa over several decades, monitoring several populations of the species in different lakes. A second ecologist is studying changes in the same fish species throughout history, relying not only on present-day data, but on information from fossils, preserved specimens, and DNA changes over time. Both scientists are interested in how this species fits into its environment and how it's changed as its environment has changed. What is the difference in the approach of these two scientists?

A) Both are studying fish evolution, but they are using different temporal scales.
B) Both are studying fish evolution, but they are using different spatial scales.
C) The first scientist is studying ecology; the second is studying evolution.
D) The first scientist is studying evolution; the second is studying ecology.