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

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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 ater 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.