Cope's Law (established by Edward Drinker Cope) states that all living organisms, from bacteria to blue whales, will grow larger over time. This idea is no longer acceptable due primarily to insular dwarfism.
This shows Amphicoelias, Bruhathkaysaurus, Brachiosaurus, Blue Whale, Quetzecoatlus, African Elephant, Indricotherium, Tyrannosaurus, and a human.