Final answer:
Appreciable changes in gene frequencies within a population over time define evolution. Population genetics examines these changes through allele frequencies, influenced by natural selection, genetic drift, and the founder effect, which collectively drive microevolution.
Step-by-step explanation:
Appreciable changes in gene frequencies within a population across time is one definition of evolution. This concept is central to the field of population genetics, which is focused on understanding microevolution—small-scale changes within a species. Population genetics measures changes in a population's allele frequencies over time to determine whether and how a population is evolving.
For example, in a population of mosquitoes in Equatorial Guinea, scientists measured the frequency of a pesticide resistance gene and found varying allele frequencies. These allele frequencies in a gene pool are expected to add up to 100%. Changes in these frequencies over time can indicate evolution; they can increase due to natural selection or change randomly via genetic drift or events like the founder effect.
Further exploring population genetics helps us grasp how factors like natural selection, genetic drift, and founder effects contribute to significant changes in the genomes of populations, providing insight into evolutionary processes and contributing to our understanding of biodiversity and adaptation.