The evaporation process requires large amounts of energy. For example, the evaporation of one gram of water requires 600 calories of heat energy . Evapotranspiration Combined loss of water to the atmosphere via the processes of evaporation and transpiration . Evergreen Vegetation Vegetation that keeps a majority of their leaves or needles throughout the year. Also see deciduous vegetation and succulent vegetation .
Evolution Is a process by which species come to possess genetic adaptations to their environment.
Its mechanism is natural selection . It also requires genetic mutations . Experiment A controlled investigation designed to evaluate the outcomes of causal manipulations on some system of interest. Exhaustible Resource See nonrenewable resource . Exploitation Form of competition where the indirect effects of the two or more species or individuals reduce the supply of the limiting resource or resources needed for survival.