Neutral theory in macroecology and population genetics

Current neutral theory in macroecology has many parallels with neutral theory in population genetics, but it also has many distinct features that arise because it focuses mainly on questions at the community level rather than at the population level. Here we highlight the similarities and differences between these two bodies of theories from the aspects of the operational units, definitions of neutrality, basic parameters, driving forces, spatial structure and community assembly rules. Compared with neutral theory in population genetics, whose development spans more than 40 years, neutral theory in ecology, which is only a few years old, is still immature and under-developed. There are many opportunities for major theoretical contributions, some of which can be adopted directly from population genetics, while others will require new theoretical work. We critically discuss these opportunities and theoretical challenges in neutral macroecology, particularly in regard to effective community size, ecological drift, community differentiation and ecological dominance.