Unifying ecology and macroevolution with individual-based theory.
Bottom Line: We show that this model generates realistic phylogenies showing a slowdown in diversification and also improves on the ecological predictions of neutral theory by explaining the occurrence of very common species.Moreover, we find the distribution of individual fitness changes over time, with average fitness increasing at a pace that depends positively on community size.Consequently, large communities tend to produce fitter species than smaller communities.
Affiliation: Department of Life Sciences, Imperial College London, Silwood Park campus, Buckhurst Road, Ascot, SL5 7PY, UK.Show MeSH
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Mentions: The introduction of selection in the UTEM has a profound impact on the relationship between time and number of extant lineages in a phylogeny: a Lineages Through Time (LTT) plot. The LTT plot from a neutral model (s = 0) shows an extreme acceleration in diversification near the present day that is rarely seen empirically. As selection increases, the resulting LTT plots straighten and become akin to the those predicted by the quite different lineage-level birth-death model of diversification (Nee et al. 1994) (Fig.6a). The ecological predictions also change with increased selection, but not dramatically. The resulting species abundance distribution at equilibrium with s = 0.01 is still log-series-like, but has an additional tail of really common species (Fig.6c), as is observed in reality but not predicted by UNTB (Ricklefs 2006; Etienne et al. 2007).
Affiliation: Department of Life Sciences, Imperial College London, Silwood Park campus, Buckhurst Road, Ascot, SL5 7PY, UK.