Dissertation Research: The Evolution of Specialized Floral Phenotypes in a Generalist Pollination Environment: Fitness Trade-offs in a Dudleya Species Complex

由几种不同类型的动物授粉的植物往往具有似乎使其适应一种特定类型的特征。这项拟议的研究利用美国西南部几种相关的植物物种，探讨了这种专门的适应如何在一个普遍的“授粉环境”中出现。在自然种群和飞行笼中进行的实验将确定哪种传粉媒介（蜂鸟或大黄蜂）在选择花的特定特征（花的长度和宽度）时最重要，以及在多大程度上更适应一种传粉媒介的花仍然可以利用另一种传粉媒介。通过探索花的适应性是如何产生的，这项研究进一步加深了我们对不同植物物种进化的理解，从而促进了生物多样性的产生。由人类活动导致的物种灭绝导致的“生物多样性危机”正在加速，这是保护生物学的核心问题。保护生物学家必须了解如何防止物种灭绝，但同样也必须了解允许新物种进化以取代灭绝物种的条件。本文提出的模型植物-传粉者系统实验将有助于我们了解开花植物物种的多样性是如何进化的，从而促进新物种的持续进化和生物多样性的维持。

Plants that are pollinated by several different types of animal nevertheless often have features which appear to adapt them to one particular type. The proposed research explores how such specialized adaptations can arise in a generalized "pollination environment", using several related plant species native to the southwestern US. Experiments in natural populations and in a flight cage will determine which pollinators (hummingbirds or bumblebees) are most important in selecting for particular features of flowers (flower length and width), and the degree to which flowers better adapted to one pollinator still can make use of the other.By exploring how floral adaptation arises, the research furthers our understanding of the evolution of distinct plant species, and thus the generation of biodiversity. An accelerating "biodiversity crisis", caused by extinction of species from human activities, is central to the science of conservation biology. Conservation biologists must understand how to prevent extinctions, but equally must understand the conditions that allow new species to evolve to replace extinct ones. The proposed experiments with a model plant-pollinator system will help us understand how the great diversity of flowering plant species has evolved, and thus how to promote ongoing evolution of new species and maintenance of biodiversity.