Phylogeny of Malvatheca (Malvaceae) and the Pace and Place of Its Evolution

0416096Baum Malvatheca是一组约2000种植物，包括几个重要的经济物种(棉花、秋葵、红麻和红麻)，根据DNA序列证据，它们从传统上公认的棉花(Malvaceae)、可可(Sterculiaceae)、Balsa(Bombacaceae)和梧桐(Tiliaceae)科在系统发育上团结在一起。大多数Malvatheca(超过1700种)是Eumalvoideae的成员，Eumalvoideae主要是草本植物和灌木，分布在世界各地。大卫·鲍姆博士和他的同事们之前的工作表明，真甲亚科的祖先是生长在澳大拉西亚的红树林和沿海小树；但只有少数现存的物种--“澳大拉西亚等级”--保留了这种习性和分布。之前的工作还表明，澳大拉西亚等级很可能是从一群中美洲和南美洲的树木--“庞巴克等级”--进化而来的。Eumalvoideae与澳大拉西亚和庞巴克等级的不同之处在于它包含的物种数量和其极其快速的分子进化(估计是庞巴克等级的九倍以上)。这项拟议的研究与同事兰迪·斯莫尔和帕特里克·莫斯一起，旨在(1)使用叶绿体基因的DNA序列和核基因GBSSI来估计澳大拉西亚等级出现的时间、时间和地点，并阐明可能导致真甲亚科分子进化加速和物种多样化的分子机制；以及(2)使用叶绿体DNA序列和核DNA数据来估计三个重要类群之间的系统发育关系。这些是(2a)猴面包树亚科，包括生长在南美洲和中美洲的许多开着壮观花朵的大树，以及一些非洲和亚洲的类群(例如，猴面包树)。这项研究将阐明后者是如何扩散到非洲/亚洲的，并将澄清花卉进化的模式。(2B)Matisieae，包括来自中美洲和南美洲的具有生态意义的林下树木。这项研究将揭示该群体的花卉和水果进化。(2C)马达加斯加芙蓉属，一群推测为芙蓉属的物种，只出现在马达加斯加。这项研究将解决他们几乎完全未知的系统发育关系，并将澄清他们何时何地到达马达加斯加。在供资期间，PI将继续为K-12教师举办一个关于系统发生(“树思维”)的讲习班，并将为此开发新的课程材料。他将通过威斯康星大学本科生研究学者计划招募本科生研究人员，该计划拥有很高比例的少数族裔/经济援助学生。此外，研究人员将在马达加斯加教授一门关于现代方法的课程，并继续在广受欢迎的生命树网站上维护锦葵科的页面。

0416096Baum Malvatheca is a group of about 2000 plant species that includes several economically important species (cotton, okra, kenaf, and balsa), united phylogenetically from the traditionally recognized cotton (Malvaceae), cocoa (Sterculiaceae), balsa (Bombacaceae), and linden (Tiliaceae) families on the basis of DNA sequence evidence. Most Malvatheca (more than 1700 species) are members of a group called the Eumalvoideae, which are primarily herbs and shrubs with a worldwide distribution. Prior work by Dr. David Baum and his colleagues suggested that the ancestors of Eumalvoideae were mangroves and coastal treelets that grew in Australasia; but only a handful of living species, the "Australasian grade," have retained this habit and distribution. The previous work also showed that the Australasian grade is likely descended from a group of Central and South American trees, the "Bombacaceous grade." The Eumalvoideae differs from the Australasian and Bombacaceous grade in the number of species it contains and in its extremely rapid molecular evolution (estimated at more than nine-fold that of the Bombacaceous grade). The proposed research, with colleagues Randy Small and Patrick Moss, aims (1) to use DNA sequences of plastid genes and the nuclear gene GBSSI to estimate when the Australasian grade arose, when and where the Eumalvoideae arose, and to shed light on the molecular mechanisms that may have led to accelerated molecular evolution and enhanced species diversification of Eumalvoideae; and (2) to use sequences of both plastid and nuclear DNA data to estimate the phylogenetic relationships within three important groups. These are (2a) Bombacoideae, a group that includes many large trees with spectacular flowers that grow in South and Central America as well as some African and Asian groups (e.g., the baobabs). The study will shed light on how the latter dispersed to Africa/Asia and will also clarify patterns of floral evolution. (2b) Matisieae, a group that includes ecologically significant understory trees from Central and South America. The study will shed light on the group's flower and fruit evolution. (2c) Malagasy Hibisceae, a group of putative relatives of Hibiscus that occur only in Madagascar. The study will resolve their phylogenetic relationships, which remain almost completely unknown, and will clarify when and from whence they arrived in Madagascar.During the funding period the PI will continue teaching a workshop for K-12 teachers on phylogenies ("tree thinking") and will develop new curricular materials for this purpose. He will recruit undergraduate researchers through the University of Wisconsin Undergraduate Research Scholars program, which has a high proportion of minority/financial aid students. Additionally, the researchers will teach a course on modern methods in Madagascar and continue to maintain the Malvaceae pages at the popular Tree of Life website.