Figure 14

Illustration of CELLS responding to STRESS at low NUTRIENT. (A-C) Illustrations of STRESS levels at sequential time steps. Only CELLS at the surface are color-coded. STRESS levels: dark blue = -2, light blue = -1, green = 0, yellow = 1, orange = 2, and red = 3. (A) During one simulation cycle, the empty space below and to the left of the starred (*) CELL is adjacent to that CELL; the CELL then moves inward to fill that empty space. (B) During the next simulation cycle, the starred CELL has a low STRESS and so becomes likely to create a new CELL. The stress algorithm allows CELLS that have equivalent immediate neighborhoods, such as the CELLS labeled 1 and 2, to have different STRESS values. Because the neighbors of CELL 1 have higher initialStress values than the neighbors of CELL 2, CELL 1 will have a higher STRESS and be more likely to create a new CELL during the simulation. (C) During the third simulation cycle the starred CELL creates a new CELL, places it in the adjacent space, resulting in a return to initial conditions. (D-F): CELL state view at equivalent TIME steps.