Dr. Siddhartha Mukherjee still remembers the first cell he cultured: It was an immune cell from a mouse, and he had grown it in a petri dish. As he examined it through a microscope, the cell moved, ...

From plants and bacteria to animals and humans, our world is filled with many living things. In fact, there are approximately 8.7 million species of plants and animals in existence, and only 1.2 ...