All biologists worth their salt know that each and every form of life has the capacity to multiply and increase at a truly astonishing, indeed a frightening rate. It is easy to do calculations demonstrating the truth of this. For example, assuming (in all cases) that all descendants survive, one bacterium dividing every 20 minutes would produce approximately 300 grams of bacteria in 24 hours; 150 million tonnes in a month. A female housefly, laying a minimum of 600 eggs in her lifetime, would, at the end of a summer of some eight to 10 generations, have × 1020 descendants – or roughly 200 million cubic metres.
