Complete the sentence: "I know a population is evolving because . . . "

"I know a population is evolving because there are observable changes in the genetic traits of the population over successive generations. This can be due to various factors such as natural selection, mutation, gene flow, and genetic drift. For example, if a certain trait becomes more common or less common over time, this is a sign of evolution. Additionally, changes in the physical characteristics or behaviors of the population can also indicate evolution. It's also important to note that evolution is a slow process that occurs over a long period of time, so these changes are usually not noticeable in the short term."