This is cyclic change because the population is consistently going up and back down.
Insulin lowers blood sugar from the body so that yôu don't get sick
Amount of wear, and how long they are may contribute with age and maybe even coloration and pigment.
Answer:
Based on the hypothesis, an increase in the ratio of Gi to Gs proteins coordinated signalling, would decrease cAMP concentration when GCPR binds to it, with the Gi function intact and able to oppose the Gs protein activation.