DISSERTATION RESEARCH: Foliar and floral evolution in geographic context: cryptic evolution in the mycoheterotrophic Pyrola picta species complex (Ericaceae)

鹿蹄草属的物种（石楠科的一部分）生长在北美西部，并拥有几个有趣的生活史属性，不同物种之间的差异，将进行调查，这项研究。这些包括直接从真菌中获取营养的特殊策略（即，真菌异养型（mycoheterotrophy），叶片从大的光合作用到微小的无功能，以及由熊蜂蜂授粉但在没有蜜蜂的情况下保留自花授粉能力的花。至少有两个发现使我们对Scotophylla组中的物种如何实现（并保持）生殖隔离的一般理解复杂化。首先，在复合体中发现的神秘物种表明，不同的遗传谱系聚集在一个非常相似的形式上。第二，物种间的杂交在物种共存的种群中以低频率被检测到。为了了解基因流与物种形成和形态多样性的关系，本研究侧重于生物地理学（即，绘制地理和遗传谱系历史）的部分暗叶使用DNA序列信息的植物跨越修订的物种范围。此外，这项研究的重点是（1）了解混合交配系统如何有助于基因流和物种多样性，（2）确定生殖隔离崩溃的原因，（3）了解发育的时间如何在叶形态，解剖，和功能在这个真菌异养植物谱系。这项研究将提供一个修订的地理范围内的物种在部分Scotophylla，描述一个新的，神秘物种，并对正在进行的关于如何识别神秘物种影响我们对生物多样性的解释的讨论做出贡献。作为成熟森林群落的基本共生元素，像鹿蹄草这样的真菌异养类群有效地作为生态系统健康的指标，最终使生态学和进化更容易为一系列受众所接受。了解鹿蹄草家族的进化历史，最终会改变人类吗？自然历史和北美西部保护生物学家正在进行的努力的看法。这项研究的结果将发表在同行评审的期刊上，在科学会议和非科学论坛上，并作为对自然历史感兴趣的学生和教师的解释性文献。

Species in genus Pyrola section Scotophylla (part of the Heath family) grow in western North America and possess several intriguing life history attributes that vary among species and will be investigated for this study. These include a special strategy for retrieving nutrition directly from fungi (i.e., mycoheterotrophy), leaves that range from large and photosynthetic to minute and non-functional, and flowers that are buzz-pollinated by bumble bees yet retain the ability to self-pollinate in the absence of bees. At least two findings complicate our general understanding of how species in section Scotophylla achieved (and maintain) reproductive isolation. First, the identification of cryptic species within the complex suggests that different genetic lineages have converged on a very similar form. Second, hybridization among species has been detected at low frequencies in populations where species co-occur. In order to understand how gene flow relates to speciation and morphological diversity, this study focuses on the phylogeography (i.e., mapping geographic and genetic lineage histories) of section Scotophylla using DNA sequence information from plants across revised species ranges. Additionally, this study focuses on (1) understanding how mixed-mating systems contribute to gene flow and species diversity, (2) determining the causes of breakdown in reproductive isolation, and (3) understanding how timing in development has played a role in the evolution of leaf morphology, anatomy, and function in this mycoheterotrophic plant lineage.This study will provide a revision of geographic ranges for species in section Scotophylla, the description of a new, cryptic species, and a contribution to ongoing discourse concerning how the recognition of cryptic species affects our interpretation of biological diversity. As fundamental, symbiotic elements of mature forest communities, mycoheterotrophic taxa like Pyrola serve effectively as indicators of ecosystem health, ultimately making ecology and evolution more accessible to a range of audiences. Understanding the evolutionary history of Pyrola lineages through time may ultimately change peoples? perceptions of both natural history and ongoing efforts by conservation biologists in western North America. Findings from this study will be available in peer-reviewed journals, at scientific conferences and in non-scientific forums, and as interpretive literature for students and teachers interested in natural history.