FIGURE 2: The growth-death trade-off in favorable conditions. Populations of cells exhibit exponential growth in favorable culture condi-tions (left). However, we cannot tell specific death rates in the environments from the growth curves. The lineage tracking approach enabled us to directly measure division and death rates that are inherent to single cells, and re-vealed the hidden trade-off relation between growth and death (right). This is an example for a macroscopic phe-nomenological law that governs cellular physiological states.