All living animals—whether herbivore, carnivore, or omnivore—need food, and plants are at the beginning of the food chain.

Like elephants and a few other animals, rhinoceroses are among the last of the large animals called "megafauna." Rhinos exist in African, Indonesian, Javan, Indian, and Sumatran varieties.¹ They are also among the rarest animals in the wild.

Bacterial cells are singularly long-lived. They keep dividing for what seems like forever. But because they are made of biochemicals, their DNA and proteins should suffer damage similar to what any other cell endures, including animal cells. What keeps bacterial cell components from wearing down?