activating invasion and metastasis Cancer biologists have known for a long time that the genes involved in developing cancer control cellular processes like these, and these processes are very ancient ones. Just because these processeas are ancient, however, does not mean that Davies is correct. His first line of argument is that cancer is found in virtually all multicellular organisms have cancer, which is true but basically irrelevant. Then he argues: The evidence that cancer is an evolutionary regression goes beyond the ubiquity of the disease. Tumors, says Davies, act like single-celled organisms. Unlike mammalian cells, for example, cancer cells are not programmed to die, rendering them effectively immortal. Also, tumors can survive with very little oxygen. To Davies and his team, which includes Australian astrobiologist Charles Lineweaver and Kimberly Bussey, a bioinformatics specialist at ASU, that fact supports the idea that cancer emerged somewhere between 1 billion and 1 and a half billion years ago, when the amount of oxygen in the atmosphere was extremely low.