CRB: Collaborative Research: Evolutionary Genetics of Adaptive Radiation in Tetramolopium

保护生物学的一个主要问题是衡量和保存遗传多样性(遗传变异程度)，特别是涉及稀有和濒危物种的情况。这是因为人们认识到，遗传多样性对于维持健康的种群和确定自然种群的进化潜力(如新物种进化的潜力)是必要的。有人提出，通过适应性辐射(从一次引种到多种生境的多样化)进化的海岛植物物种可以为分析珍稀植物遗传多样性的数量和结构提供模式系统。向日葵家族中的四倍体属为分析稀有物种的遗传多样性提供了独特的机会。该属仅出现在太平洋的海洋岛屿上，并在新几内亚、夏威夷和库克群岛中有不寻常的分布。在11种夏威夷物种中，有10种被认为是稀有和濒危物种。根据现有证据，新几内亚是四钼的发源地，后来又扩散到其他太平洋岛屿。这项研究的两个具体目标是：1.评估引入夏威夷的遗传多样性的初始数量，并将这一值与目前夏威夷物种中发现的值进行比较。这将通过使用两种独立的分子技术比较新几内亚物种和夏威夷物种的遗传多样性来实现。2.确定夏威夷物种中有多少基因参与适应性辐射过程，并估计这些基因在总基因库中所占的比例。这将是第一批确定和定位控制形态差异的基因数量的非驯化植物物种之一。这项研究的结果将提供详细的信息，这些信息对于管理受威胁和濒危的植物物种将是非常宝贵的。

A major concern of Conservation Biology is the measurement and preservation of genetic diversity (degree of genetic variation) particularly where rare and endangered species are involved. This is so because genetic diversity is recognized as being necessary for maintenance of healthy populations and for determining the evolutionary potential (such as the potential for new species to evolve) of natural populations. It is proposed that island plant species that have evolved through adaptive radiation (diversification into a variety of habitats from a single introduction) can provide the model systems for analysis of the amount and structure of genetic diversity for rare plants in general. The genus Tetramolopium in the Sunflower family presents a unique opportunity to analyze genetic diversity in rare species. The genus occurs only on oceanic islands in the Pacific Ocean and has an unusual distribution among New Guinea, Hawaii, and the Cook Islands. Ten of the eleven Hawaiian species are considered rare and endangered. Based on available evidence New Guinea is the source area where Tetramolopium evolved and was later dispersed to the other Pacific islands. The two specific goals of the research are: 1. To assess the initial amount of genetic diversity that was introduced into Hawaii and compare this value to those found in the present Hawaiian species. This will be accomplished by comparing genetic diversity in New Guinea species to those in Hawaii through use of two independent molecular techniques. 2. To determine how many genes are involved in the process of adaptive radiation in Hawaiian species and estimate the proportion of the total gene pool represented by these genes. This will be one of the first non-domesticated plant species to have the number of genes controlling morphological differences determined and mapped. The results of this research will provide detailed information that will be invaluable for the management of threatened and endangered plant species.