Dissertation Research: The Evolution and Diversification of Bursera subgenus Bullockia (Burseraceae).

生物学家声称，物种间的杂交是植物中一种重要的进化现象，但绝大多数确凿的证据来自于对生长在温带气候中的草药的研究。 因此，我们不知道这种说法如何准确地描述热带木本植物的进化生物学。 为了解决这个想法的适用性，热带植物，我们将研究一组热带树木吹捧其倾向杂交在物种和种群水平。 该集团，Bursera亚属Bullockia（家庭Burseraceae），包括超过40种，从亚利桑那州到玻利维亚的范围。 据说它包括少数稳定的杂交物种和多个本地化的杂交群体。 我们将使用核DNA序列和叶绿体限制性位点数据构建物种关系的遗传学或进化假说，以确定“杂交”物种是否确实存在于这一组中。 我们还将遗传指纹的一个潜在的混合群Bursera物种位于加拉帕戈斯测试杂交，并阐明这些长寿的树木物种之间的基因流的地理组成部分。 这项研究的结果将有助于新的信息，我们广义的了解杂交在热带，木本植物，而他们增加了系统的知识Bursera和专门的热带家庭的树木，它属于。意义摘要：（197字）这个项目将研究一个普遍持有的信念，在植物进化生物学使用一组热带树木。 这种评估是重要的，因为种间杂交是一种有效的，相对普遍的进化现象的前提是主要基于温带，草本植物的信息，并不一定适用于热带木本植物，有根本不同的生活史。 我们将增加我们的广义理解的程度和进化的后果种间杂交的测试声称稳定的杂交种在热带，木本植物属，Bursera（家庭Burseraceae）。 我们还将通过测试加拉帕戈斯Bursera的孤立的、地质上年轻的种群，以获得报告的基因渗入证据，来提高我们对热带木本植物之间杂交群体和基因流形成的理解。 此外，该项目所产生的进化关系的假设将有助于新的信息Bursera和Burseraceae，一个家庭大多未在分子水平上研究的系统学。 这个项目将有助于回答不仅是长期存在的问题，这个特定的群体的进化历史，如是否稳定的杂交Bursera物种存在，是否Bursera可以形成种间杂交群体，但也是否Bursera和Commiphora，其非洲亲戚，是同源的。

Common Summary for non-specialists: (217 words)Biologists have claimed that hybridization between species is an important evolutionary phenomenon in plants, yet the vast majority of corroborating evidence derives from research using herbs growing in temperate climates. As a consequence, we do not know how accurately this assertion describes the evolutionary biology of tropical woody plants. To address the applicability of this idea to tropical plants, we will examine a group of tropical trees touted for its propensity to hybridize at the species and population level. The group, Bursera subgenus Bullockia (family Burseraceae), consists of over 40 species that range from Arizona to Bolivia. It is purported to include a handful of stabilized hybrid species and multiple, localized hybrid swarms. We will construct phylogenies or evolutionary hypotheses of relationships of the species using nuclear DNA sequences and chloroplast restriction site data to determine whether "hybrid" species indeed exist in this group. We will also genetically fingerprint a potential hybrid swarm of Bursera species located in the Galapagos to test for hybridity and to elucidate the geographic component of gene flow between species of these long-lived trees. The results of this study will contribute new information to our generalized understanding of hybridization in tropical, woody plants while they augment the systematic knowledge of Bursera and the exclusively tropical family of trees to which it belongs.Significance summary: (197 words)This project will examine a commonly held belief in plant evolutionary biology using a group of tropical trees. This assessment is significant because the premise that interspecific hybridization is a potent, relatively common evolutionary phenomenon is based primarily on information from temperate, herbaceous plants and need not necessarily apply to tropical woody plants, which have radically different life histories. We will increase our generalized understanding of the extent and evolutionary consequences of interspecific hybridization by testing purported stabilized hybrid species in a tropical, woody plant genus, Bursera (family Burseraceae). We will also improve our understanding of the formation of hybrid swarms and gene flow between tropical, woody plants by testing the isolated, geologically young populations of Galapagos Bursera for reported evidence of introgression. Additionally, the hypotheses of evolutionary relationships generated by this project will contribute new information to the systematics of Bursera and the Burseraceae, a family mostly unstudied at the molecular level. This project will help answer not only longstanding questions about the evolutionary history of this particular group such as whether stabilized hybrid Bursera species exist and whether Bursera can form interspecific hybrid swarms but also whether Bursera and Commiphora, its African relative, are congeneric.