Fig. 6.14. The genetic structure of populations can be crudely classified into three basic types. A) Distinct populations, where gene flow is low enough for genetic divergence. B) Continuous change, where genetic composition changes continuously over space, resulting in isolation by distance. C) No differentiation, where gene flow is so extensive that genetic homogeneity prevails across the entire region. Adapted from Laikre et al. 2005. Clipart by X. Dengra.
