Scientists explain how diverse species coexist in microbial communities

Diversity in many biological communities is a sign of an ecosystem in balance. When one species dominates, the entire system can go haywire. For example, the uncontrolled overgrowth of certain oceanic algae species causes toxic red tides that kill fish and other sea life, and sicken humans. On a more individual level, the human gut hosts a large community of different bacteria that is crucial for proper digestion and absorption of nutrients. Disruption of or imbalances in this bacterial community can cause a bloom in the growth of a toxic species, causing nausea, diarrhea and other illnesses. Plainly, there's an urgent need to understand how microbial community diversity is developed and maintained, especially as human activities change our external and internal environments.