Silvester de Nooijer, Barbara R. Holland, David Penny

Eukaryote cells are suggested to arise somewhere between 0.85~2.7 billion years ago. However, in the present world of unicellular organisms, cells that derive their food and metabolic energy from larger cells engulfing smaller cells (phagocytosis) are almost exclusively eukaryotic. Combining these propositions, that eukaryotes were the first phagocytotic predators and that they arose only 0.85~2.7 billion years ago, leads to an unexpected prediction of a long period (approximately 1-3 billion years) with no phagocytotes -- a veritable Garden of Eden.