Simplify the following text for a Grade 12 native English-speaking person.
Original: Macroevolutionary studies focus on change that occurs at or above the level of species , in contrast with microevolution , which refers to smaller evolutionary changes ( typically described as changes in allele frequencies ) within a species or population .
Simplified: Microevolution , on the other hand , refers to smaller evolutionary changes within species or populations . Microevolution can typically be described as changes in allele frequencies .