This daily feast-and-famine cycle in oxygen availability created an intense physiological challenge for early animals, forcing them to develop adaptations to handle fluctuations in nutrients. For ...

Carrion flies locate dead animals through a keen sense of smell ... digest it, and then cycle the nutrients back into the environment through their feces, after respiration and assimilation.

Photo Credit: NASA Oxygen-starved ocean “dead zones,” where fish and animals cannot survive ... nitrogen into the ocean from human activity can impact the ocean’s nutrient cycle. “The key questions ...