Years would be the independent variable because any sort of time is usually the independent variable.
The practice of caloric restriction involves consuming a balanced diet but restricting your caloric intake by approximately 25% below the level of energy consumed in a freely chosen diet.
Tigers are a very important part of the food chain, but sadly they are going extinct. Their habitats are being destroyed, forcing the tigers to kill farmers livestock. In some countries tigers are still used for medicinal purposes, so they are often hunted for their teeth and pelts. Tigers may not seem important but they play a very important part on the food chain. Without these tigers the population of boars and other prey would sky-rocket and that would not be good for the environment.
