Evolution of generalist pollination systems

不同的物种可以采取非常不同的策略来利用环境中的资源。生态专家使用的资源范围很窄，而通才使用的资源范围很广。这些差异可能对生态系统的稳定性产生重要影响，因为通才对环境变化更敏感。事实上，我们很容易想到，一种依赖于单一物种授粉的植物比一种可以被许多物种授粉的植物更容易受到伤害。历史上，授粉生物学家的注意力主要集中在专门化系统的研究上，也许是因为它们更引人注目。一个经典的例子是达尔文的Angraecum sesquipedale兰花和它的预测（并最终证实）长喙授粉蛾。然而，越来越多的研究者呼吁对植物的通才系统进行深入研究，因为这些系统在植物进化中非常重要。本研究针对苦苣苔科加勒比群岛植物群中通才授粉策略的机制和后果。我提出了三个短期目标，第一个目标是确定产生通才战略的过程。具体来说，我将测试通才的进化成功是否是由于他们已经进化出特征创新，使他们能够成功地由不同的传粉者授粉。这将包括在研究传粉者的有效性，但也花的形状差异种群的物种与对比pollinationstrategy.In第二个目标，我将测试，如果在独立进化的聚合形态性状与通才策略的分子机制涉及相同的基因或基因组区域。这将涉及不同来源的通才的比较QTL定位以及比较转录组学研究。最后，第三个目标将解决通才系统的意义。它将使用系统发育方法测试通才是否比专家具有更高的多样化率，以及海洋岛屿上物种的存在是否影响这些比率。这一提议有可能通过展示生态通才策略的进化方式和量化其进化成功来彻底改变我们对生态通才策略的看法。

Different species can adopt very different strategies to use the resources in their environments. Ecological specialists use a narrow range of resources whereas generalists use a broad range. These differences can have important implications for the stability of ecosystems as generalists are more robust to environmental changes. Indeed, it is easy to conceive that a plant relying on a single species of pollinator for its reproduction will be more vulnerable than a species that can be pollinated by many species.Historically, the attention of pollination biologists has been mostly directed towards the study of specialization systems, perhaps because they are more spectacular. One classic example is Darwin's Angraecum sesquipedale orchid and its predicted (and eventually confirmed) long proboscis pollinating moth. Yet, more and more researchers are calling for further studies on generalist systems as these are abundant and have been important in plant evolution.This proposal addresses specifically the mechanisms and consequences of generalist pollination strategies in a plant group from the Caribbean Islands from the Gesneriaceae family. I propose three short-term objectives.In the first objective, I will determine the processes that gave rise to generalist strategies. Specifically, I will test if the evolutionary success of generalists is due to the fact that they have evolved trait innovations that allows them to be successfully pollinated by different pollinators. This will consist in studying pollinator effectiveness, but also the floral shape variance in populations of species with contrasting pollination strategies.In the second objective, I will test if the molecular mechanisms involved in the independent evolution of convergent morphological traits associated with generalist strategies involved the same genes or genome regions. This will involve comparative QTL mapping of generalists of different origins as well as comparative transcriptomic studies.Finally, the third objective will address the significance of generalist systems. It will test if generalists have higher diversification rates than specialists using phylogenetic approaches, and if the presence of species on oceanic islands affect these rates. This proposal has the potential to drastically change the way we perceive ecological generalist strategies by showing how they evolve and by quantifying their evolutionary success.