Is specialization an evolutionary dead-end? Testing for differences in speciation, extinction and trait transition rates across diverse phylogenies of specialists and generalists.

Specialization has often been claimed to be an evolutionary dead end, with specialist lineages having a reduced capacity to persist or diversify. In a phylogenetic comparative framework, an evolutionary dead end may be detectable from the phylogenetic distribution of specialists, if specialists rarely give rise to large, diverse clades. Previous phylogenetic studies of the influence of specialization on macroevolutionary processes have demonstrated a range of patterns, including examples where specialists have both higher and lower diversification rates than generalists, as well as examples where the rates of evolutionary transitions from generalists to specialists are higher, lower or equal to transitions from specialists to generalists. Here, we wish to ask whether these varied answers are due to the differences in macroevolutionary processes in different clades, or partly due to differences in methodology. We analysed ten phylogenies containing multiple independent origins of special...特化常被视为演化的死胡同，特化支系的存续或分化能力往往有所受限。在系统发育比较框架（phylogenetic comparative framework）下，若特化类群极少衍生出庞大且多样的演化支（clade），则可通过特化类群的系统发育分布检测演化死胡同现象。此前针对特化对宏观进化过程（macroevolutionary processes）影响的系统发育研究，已报道了多种模式：例如特化类群的分化速率既可能高于也可能低于广适类群；从广适类群向特化类群的演化转换速率，也分别存在高于、低于或等于从特化类群向广适类群转换速率的情况。本研究旨在探究这些不一致的研究结论，究竟源于不同演化支间宏观进化过程的差异，还是部分源于研究方法的不同。我们分析了10个包含多次独立特化起源的系统发育树……