Rundell Rebecca J, Price Trevor D
Committee on Evolutionary Biology, University of Chicago, Chicago, IL 60637, USA.
Trends Ecol Evol. 2009 Jul;24(7):394-9. doi: 10.1016/j.tree.2009.02.007. Epub 2009 May 4.
Radiations of ecologically and morphologically differentiated sympatric species can exhibit the pattern of a burst of diversification, which might be produced by ecological divergence between populations, together with the acquisition of reproductive isolation ('ecological speciation'). Here we suggest that this pattern could also arise if speciation precedes significant ecological differentiation (i.e. through geographical isolation and nonadaptive radiation). Subsequently, species ecologically differentiate and spread into sympatry. Alternative routes to producing ecologically differentiated sympatric species are difficult to detect in old radiations. However, nonadaptive radiations are common and might therefore regularly be responsible for currently ecologically differentiated sympatric species (e.g. among groups that are not susceptible to ecological speciation). Species evolving nonadaptively over long periods might eventually replace young, ecologically produced species.
生态和形态上分化的同域物种辐射可能呈现出多样化爆发的模式，这可能是由种群间的生态分化以及生殖隔离的获得（即“生态物种形成”）所导致的。在这里，我们认为，如果物种形成先于显著的生态分化（即通过地理隔离和非适应性辐射），这种模式也可能出现。随后，物种在生态上发生分化并扩散到同域分布。在古老的辐射中，产生生态分化的同域物种的其他途径很难被检测到。然而，非适应性辐射很常见，因此可能经常导致目前生态上分化的同域物种（例如在不易发生生态物种形成的类群中）。长期非适应性进化的物种最终可能取代年轻的、由生态作用产生的物种。
