The question of how single celled organisms evolved into more dynamic multicellular ones is difficult to answer, but scientists in Tennessee believe genetic on/off switches provide a clue. "How colonies of single cells evolved into multicellular organisms has long been a puzzle. The process requires single cells to band together and divide the tasks of life. To do so, some cells must give up their ability to reproduce," says the New Scientist. "To investigate, Sergey Gavrilets of the University of Tennessee in Knoxville created a mathematical model describing a colony of identical cells able to survive and reproduce. He assumed trade-offs between the tasks: being better at reproducing made cells worse at survival, and vice versa. In the simplest case, the colony evolved into organisms made of cells that were mediocre at both tasks."