Definition: In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.
Input: Population growth is the rate at which a population grows or expands .
Output:
The " population growth rate " is the rate at which the number of individuals in a population increases in a given time period , expressed as a fraction of the initial population .