Population genomics is the large-scale comparison of genomes of individuals in a population. These comparisons can be used for many purposes, such as tracing changes in demography within populations or identifying how genetic variation related to specific traits vary in prevalence over time and space.
In humans for example, population genomics has helped support the ‘Out of Africa’ hypothesis in paleoanthropology – that humans originated in Africa and spread out across the world from 100,000 to 50,000 years ago. It has also shown how genetic changes can be linked to lifestyle and environment. For example, alleles involved in the persistence of the enzyme lactase are more common in certain parts of the world where dairy is a dietary component. This means population genomics can give insights into microevolution – evolutionary change within a species over a relatively short geological time.
Much of the development of population genomics can be attributed to improvements in sequencing technology. High-throughput sequencing techniques have allowed the acquisition of many genome sequences over a relatively short period of time. For further discussion of the rapid advancements in the field of sequencing, see the 'Reading DNA' page.