CO2. But we did not have bacteria to eat dead wood. They came much later. So we accumulated layers and layers of wood. It has turned into coal. Coal is solid carbon from CO2. 12
more likely to die. It does not affect all animals. Naked Mole Rats, lobsters do not lose fitness with time. Many trees age in reverse: they become stronger over time. 18
35 trillion cells in your whole body. They all came from one of your mother's cell. Divided by two, then by two then by two. Plus about 100 trillion bacteria. Most of your cells are in your digestive system (bacteria). 24