Here's why:
* Changes in groups of organisms over time: This refers to the accumulation of changes in the genetic makeup of a population over generations. These changes can be small or large, and they are driven by various factors like mutations, natural selection, genetic drift, and gene flow.
* Variations in a population: The changes over time lead to a greater diversity of traits within a population. This variation is essential for adaptation to changing environments.
Therefore, the changes in groups of organisms over time producing variations in a population is a core concept in the theory of evolution.
