If a drought occurred reducing the amount of available water, some trees, such as those with deep roots that can reach the water table, would be naturally selected over other trees. if the drought continued for an extended period of time, the trees would likely evolve until most of the trees possessed drought-resistant characteristics. which of the following allows natural selection and evolution to occur? a. increasing the height of the water table b. having an identical genetic make-up c. differences in the characteristics of individual trees d. using other plant parts instead of roots to absorb water