The mode of pheromone evolution: evidence from bark beetles
The mode of pheromone evolution: evidence from bark beetles
复制标题
DOI：
10.1098/rspb.2003.2647
复制
发表时间：
2004-04-22
影响因子：
4.7
通讯作者：
Elgar, MA
中科院分区：
文献类型：
--
作者：
Symonds, MRE;Elgar, MA
性和聚集信息素由物种特异性的化学物质混合物组成。不同物种的混合进化方式一直是一些争论的话题。理论预测表明，物种之间的差异不是通过微小变化的积累而产生的，而是通过化学成分的重大变化而产生的。利用 Dendroctonus 和 Ips 这两个属的 34 种树皮甲虫的聚集信息素数据，我们研究了它们信息素混合物的化学成分的分布如何反映它们的系统发育关系。我们测试了是否存在可用于帮助阐明信息素进化模式的一致模式。尽管两个属之间的信息素混合物存在明显差异，但每个属内物种之间的差异遵循不太清晰的系统发育模式。在这两个属中，密切相关的物种与关系较远的物种一样存在差异。特别是在 Dendroctonus 中，大多数化学成分在整个系统发育中随机分布。事实上，对于某些化学品而言，密切相关的物种实际上可能比化学成分随机分布所预期的差异更大。这强烈反对信息素进化中发生微小变化的想法。相反，我们认为，在某些系统发育限制下，树皮甲虫的信息素进化具有较大的突变特征，导致兄弟物种在表型上（即信息素）彼此显着不同，从而与理论预测一致。
Sex and aggregation pheromones consist of species-specific blends of chemicals. The way in which different species' blends have evolved has been the subject of some debate. Theoretical predictions suggest that differences between species have arisen not through the accruing of small changes, but through major shifts in chemical composition. Using data on the aggregation pheromones of 34 species of bark beetle from two genera, Dendroctonus and Ips, we investigated how the distributions of the chemical components of their pheromone blends mirror their phylogenetic relationships. We tested whether there were consistent patterns that could be used to help elucidate the mode of pheromone evolution. Although there were obvious differences in pheromone blends between the two genera, the differences between species within each genus followed a less clear phylogenetic pattern. In both genera, closely related species are just as different as more distantly related species. Within Dendroctonus, particularly, most chemical components were distributed randomly across the phylogeny. Indeed, for some chemicals, closely related species may actually be more different than would be expected from a random distribution of chemical components. This argues strongly against the idea of minor shifts in pheromone evolution. Instead, we suggest that, within certain phylogenetic constraints, pheromone evolution in bark beetles is characterized by large saltational shifts, resulting in sibling species being substantially phenotypically (i.e. pheromonally) different from one another, thus agreeing with theoretical predictions.