Take a moment to stop and notice the life all around you: millions of species of plants and animals, all living, dieing, evolving all around us. Some animals come and go in the blink of an eye, others live longer than humans. All organisms go through three distinct phases of life, but why do different animals have different life spans? Why do some animals of a given species live for many years, while others live for only a few? The web of life is amazing, intricate and varying — and we’re all interconnected in big and small ways.