  Evolutionary and ecosystem dynamics are often treated as different processes
--operating at separate timescales-- even if evidence reveals that rapid
evolutionary changes can feed back into ecological interactions. A recent
long-term field experiment has explicitly shown that communities of competing
plant species can experience very fast phenotypic diversification, and that
this gives rise to enhanced complementarity in resource exploitation and to
enlarged ecosystem-level productivity. Here, we build on progress made in
recent years in the integration of eco-evolutionary dynamics, and present a
computational approach aimed at describing these empirical findings in detail.
In particular we model a community of organisms of different but similar
species evolving in time through mechanisms of birth, competition, sexual
reproduction, descent with modification, and death. Based on simple rules, this
model provides a rationalization for the emergence of rapid phenotypic
diversification in species-rich communities. Furthermore, it also leads to
non-trivial predictions about long-term phenotypic change and ecological
interactions. Our results illustrate that the presence of highly specialized,
non-competing species leads to very stable communities and reveals that
phenotypically equivalent species occupying the same niche may emerge and
coexist for very long times. Thus, the framework presented here provides a
simple approach --complementing existing theories, but specifically devised to
account for the specificities of the recent empirical findings for plant
communities-- to explain the collective emergence of diversification at a
community level, and paves the way to further scrutinize the intimate
entanglement of ecological and evolutionary processes, especially in
species-rich communities.
