Ocean water moves in predictable ways along the ocean surface. Surface currents can flow for thousands of kilometers and can reach depths of hundreds of meters. These surface currents do not depend on weather; they remain unchanged even in large storms because they depend on factors that do not change.
Surface currents are created by three things:
global wind patterns
the rotation of the Earth
the shape of the ocean basins
Surface currents are extremely important because they distribute heat around the planet and are a major factor influencing climate around the globe.
Exposure to environmental stress or pathogens is the fuel that ensures the fitness as well as the survival of species population. These factors leads to adaptation of the cells of the species to survive.