Complex Dance of Light-Seeking Algae in Light Gradients

A population of photosynthetic algae has been shown to exhibit a highly nonlinear response to light, forming dynamic structures in light-intensity gradients. Two longstanding questions about this light response regard how light-seeking cells move in a light-intensity gradient and whether this motion depends on cell concentration. Aina Ramamonjy and colleagues investigated the dynamics of dilute and semi dilute suspensions of these algae in a light-intensity gradient (varying from darkness to bright green light). The results could improve our understanding of how groups of photosynthetic organisms arrange themselves into dynamic patterns to control the amount of light that they receive.