Population Genetics is a branch of biology that studies the genetic composition of populations and how it changes over time. It focuses on the distribution of and changes in allele frequencies within populations, which can be influenced by factors such as natural selection, genetic drift, mutation, and gene flow. By analyzing these genetic variations, scientists can understand how populations evolve and adapt to their environments. This field also helps in conservation efforts by assessing genetic diversity, which is crucial for the survival of species, and in understanding the genetic basis of diseases in human populations.