Chemical niche differentiation among sympatric species of orchid bees.
Chemical niche differentiation among sympatric species of orchid bees.
复制标题
兰花蜂同域物种之间的化学生态位分化。
作者：
Y. Zimmermann;S. Ramírez;T. Eltz
雄性新热带兰花蜂（Euglossini）从花朵和其他来源（如腐烂的木头）收集挥发性物质（香味），并将它们储存在专门的胫骨后袋中。积累的化学物质随后在求偶时释放出来，可能是为了吸引同种雌性交配。本研究分析了巴拿马15种同域蜜蜂的胫骨香味，以验证其群落是否具有化学结构，并阐明雄性香味信号是否进化为传递过早交配隔离的信号。我们的分析揭示了所有谱系之间存在着巨大的化学差异。差异是由某些物种独有的化合物介导的，但也由共享化合物相对数量的差异介导。我们利用COI、ef1 - α、ArgK和Pol-II的部分序列对每个物种中存在的胫骨香味化合物进行了基于dna的系统发育图谱（重建），发现大多数优势化合物是高度同源的。在一项与系统发育差异相关的化学分化分析中，在进化史上的任何时刻，差异都比零模型所预期的要大，这表明多样化的选择塑造了香味的表型。值得注意的是，化学差异在最近分化的谱系中比在它们之间更大，这表明兰花蜂的化学偏好在物种分化的早期阶段进化得很快。我们假设交流干扰是所观察到的香味分化背后的可能机制，这可能是生殖特征（香味）位移的产物。我们的研究结果与男性气味信号进化以传达早熟隔离的假设是一致的。
Male Neotropical orchid bees (Euglossini) collect volatile substances (fragrances) from flowers and other sources (e.g., decaying wood) and store them in specialized hind tibial pockets. The accumulated chemicals are later emitted during courtship display, presumably to lure conspecific females for mating. We analyzed tibial fragrances of males of 15 sympatric Panamanian species in the genus Euglossa to test whether communities of euglossine bees are chemically structured, and to elucidate whether male fragrance signals evolve to convey premating isolation. Our analysis revealed substantial chemical disparity among all lineages. Disparity was mediated by compounds that were exclusive to certain species but also by differences in relative quantity of shared compounds. We mapped tibial fragrance compounds present in each species on a DNA-based phylogeny (reconstructed using partial sequences of COI, EF1-alpha, ArgK, and Pol-II) and found that most dominant compounds were highly homoplasious. In an analysis of chemical differentiation in relation to phylogenetic divergence through time, disparity was greater than expected from a null model at any point during evolutionary history, suggesting that diversifying selection has shaped fragrance phenotypes. Notably, chemical disparity was greater within recently diverged lineages than among them, suggesting that chemical preferences in orchid bees evolved rapidly in the early stages of species divergence. We postulate communication interference as the possible mechanism behind the observed fragrance differentiation, which may be the product of reproductive character (fragrance) displacement. Our findings are consistent with the hypothesis that male fragrance signals evolve to convey premating isolation.
影响因子：
7
作者：
Robertson, Hugh M.;Wanner, Kevin W.
通讯作者：
Wanner, Kevin W.