Using the example from the lecture, define cyclic population change and explain how it works.

Okay, let’s look at an environment with say, wolves and mice. Now of course, the wolves are the predators and the mice are the prey. Because wolves eat mice. For now, let’s ignore outside factors - like climate change for example. And just look at how the populations of these two species are um, are affected by each other. It might be helpful to look at this process in phases. So, phase 1 - uh let’s say that we have a lotta mice, and only a few wolves. Well with so many mice around the wolves have a large food supply. And with all that food they can live longer and healthier, and they can reproduce and feed their young. So, the wolf population will grow, right? But now, there are more wolves, all eating mice, so the mice population starts to decline, since more mice are getting eaten. So we arrive at phase 2: a lotta wolves, and a declining mouse population. Are you with me? I-In this stage, there are fewer mice around, which means, the wolves won’t have much food, suddenly it’s harder for them to survive, let alone to feed their young. So, the wolf population starts shrinking, therefore, eating fewer mice, and this allows the mouse population to grow! And, where are we now? Phase 3: not many wolves, but a lotta mice! Which is exactly where we started. Phase 3 is in fact equivalent to phase 1. As you see, we’ve got a repeating pattern.