Speciation and the neutral theory of biodiversity

Abstract

The neutral theory of biodiversity purports that patterns in the distribution and abundance of species do not depend on adaptive differences between species (i.e. niche differentiation) but solely on random fluctuations in population size ("ecological drift"), along with dispersal and speciation. In this framework, the ultimate driver of biodiversity is speciation. However, the original neutral theory made strongly simplifying assumptions about the mechanisms of speciation, which has led to some clearly unrealistic predictions. In response, several recent studies have combined neutral community models with more elaborate speciation models. These efforts have alleviated some of the problems of the earlier approaches, while confirming the general ability of neutral theory to predict empirical patterns of biodiversity. However, the models also show that the mode of speciation can have a strong impact on relative species abundances. Future work should compare these results to diversity patterns arising from non-neutral modes of speciation, such as adaptive radiations.

The Unified Neutral Theory of Biodiversity and Biogeography at Age Ten

“…This illustrates limitations to the inferences that one can make from species abundance distributions alone. Point mutation speciation assumption The way in which speciation is modelled in neutral theory has received much attention [33]. The original neutral model assumes a 'point mutation' mode of speciation, where, with each birth in the metacommunity, there is a small probability n that the newborn founds a new species [2].…”

Limnephilid taxa revised by speciation traits: Rhadicoleptus, Isogamus, Melampophylax genera, Chaetopteryx rugulosa, Psilopteryx psorosa species groups, Drusus bolivari, Annitella kosciuszkii species complexes (Trichoptera: Limnephilidae)

“…Today unified neutral theory of biodiversity and biogeography assume neutrality of individuals within communities (Rosindell et al 2011). Patterns in species distribution do not depend on adaptive differences between species, but on random fluctuations, dispersal, and speciation (Kopp 2010). The study and valid demonstration of positive (adaptive) Darwinian selection in natural populations has remained still difficult and can be also difficult to verify whether genes that behave as outlier are genuinely adaptive (Liukart et al 2003).…”

The case for ecological neutral theory

“…Gone are the days when proponents and opponents of neutral theory could build their cases on good or bad fits of one particular neutral model to some empirical species abundance distribution [1][2][3][4][5]. Here, we complement the recent reviews [6][7][8][9] and opinions [10][11][12][13][14] with our own opinion on how neutral theory can aid progress in ecological research. The opposition to neutral theory in ecology is not surprising given its radical assumption and we view such criticism as necessary for neutral theory to grow.…”