Inferring genetic connectivity in real populations, exemplified by coastal and oceanic atlantic cod

Significance Estimates of migration are important for understanding the dynamics of natural populations. A statistic known as FST is often used to measure levels of genetic differentiation among natural populations. Equations that translate FST into estimates of migration are based on “ideal” populations, which are subject to many simplifying assumptions compared with real populations. Therefore, theoretical estimates of migration might not be realistic. We modeled populations of Atlantic cod in the North Sea and the adjacent Skagerrak region to compare how migration is related to the complexities of real populations, and how actual migration compares with predictions based on theory. Resul…