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系列报告之一：
报告人：Robert E. Ricklefs
报告题目：Global distribution of species richness: patterns and explanations
报告人：Susanne S. Renner
报告题目：The evolution and function of sex chromosomes in land plants
报告地点：综合实验楼一楼报告厅
报告时间：3月2号，8:30－11:00
Global distribution of species richness: patterns and explanations.
Abstract: The number of species within a small area decreases towards higher latitudes in most groups of organisms. Traditional explanations related diversity to the physical characteristics of local environments, which influenced the outcomes of interactions among species that determined their ability to coexist. More recently, processes at larger scales, including the diversification of species within regions, have received more attention. I will discuss approaches to distinguishing these different types of explanations.
The evolution and function of sex chromosomes in land plants
Abstract: Sex chromosomes in land plants evolved as a consequence of close linkage between the two sex determination genes with complementary dominance required to establish stable dioecious populations. Based on cytological and molecular evidence, sex chromosomes are found in at least 48 species across 20 families, including several species of hepatics and leafy mosses, at least five species in three families of gymnosperms, and at least 39 species in 15 families of angiosperms. The sex chromosomes in hepatics, mosses, and gymnosperms so far known are morphologically heteromorphic. In angiosperms, heteromorphic sex chromosomes are found in at least 19 species in four families, homomorphic sex chromosomes in about the same number of species in 13 families. Two families, Caryophyllaceae and Cucurbitaceae, have both heteromorphic and homomorphic sex chromosomes. The prevalence of the XY system, 44 (92%) out of 48 species, may reflect the predominance of the evolutionary pathway from gynodioecy towards dioecy. All dioecious species have the potential to evolve sex chromosomes, and reversions back from dioecy to gynodioecy or androdioecy have also occurred, for example, in Cariaca papaya and Datisca cannabina. Such reversals may occur especially during the early stages of sex chromosome evolution before the lethality of YY (or WW) genotype is established.
系列报告之二：
报告人：Susanne S. Renner
报告题目：Oil bees and oil-offering flowers: Disentangling coevolution and host switching
报告人：Robert E. Ricklefs
报告题目：Distribution and abundance of species within regions
报告地点：综合实验楼一楼报告厅
报告时间：3月8号，8:30－11:00
Distribution and abundance of species within regions.
Abstract: Local diversity reflects both the number of species within a region, but also how these species are distributed within regions. Locally, patterns of relative abundance of species have been used to infer underlying processes of organizing communities and limiting species membership. However, the presence and abundance of a species in one locality reflects its interactions with other species throughout its regional distribution. The species population is the basic unit of community ecology, and it is important to understand regional patterns of species distributions for interpreting diversity and relative abundance locally. One striking observation is that species distributions are independent of the number of other closely related species, hence potential competitors. Another is that distributions are very changeable in evolutionary time. I will discuss the implications of these findings for interpreting diversity patterns.
Oil bees and oil-offering flowers: Disentangling coevolution and host switching
Abstract: The interactions between bees that depend on floral oil for their larvae and flowers that offer oil involve an intricate mix of obligate and facultative mutualisms. Using recent phylogenies, new data on oil-offering Cucurbitaceae, and molecular-dating, we ask when and how often oil-offering flowers and oil-foraging bees evolved, and how frequently these traits were lost in the cause of evolution. Local phylogenies and an angiosperm-wide tree show that oil flowers evolved at least 28 times and that floral oil was lost at least 36–40 times. The oldest oil flower systems evolved shortly after the K/T boundary independently in American Malpighiaceae, tropical African Cucurbitaceae and Laurasian Lysimachia (Myrsinaceae); the ages of the South African oil flower/oil bee systems are less clear. Youngest oil flower clades include Calceolaria (Calceolariaceae), Iridaceae, Krameria (Krameriaceae) and numerous Orchidaceae, many just a few million years old. In bees, oil foraging evolved minimally seven times and dates back to at least 56 Ma (Ctenoplectra) and 53 Ma (Macropis). The co-occurrence of older and younger oil-offering clades in three of the four geographical regions (but not the Holarctic) implies that oil-foraging bees acquired additional oil hosts over evolutionary time. Such niche-broadening probably started with exploratory visits to flowers resembling oil hosts in scent or colour, as suggested by several cases of Muellerian or Batesian mimicry involving oil flowers.
系列报告之三：
报告人：Susanne S. Renner
报告题目：The origin of cucumber and melon: "Both species have their wild progenitors in Asia, not Africa"
报告人：Robert E. Ricklefs
报告题目：Speciation, extinction, and the regional pool of species
报告地点：综合实验楼一楼报告厅
报告时间：3月14号，8:30－11:00
Speciation, extinction, and the regional pool of species.
Abstract: The number of species that co-occur locally parallels the number of species in the larger region. Thus, to interpret patterns of species richness, it is important to understand the process of species diversification. Fossil information from some regions has been helpful in this regard. However, lacking detailed fossil records for most groups, we are limited in our ability to describe patterns of diversification. Phylogenetic reconstruction of the relationships of contemporary species has been disappointing. The relationship of clade size to region area and latitude provides some information. I shall outline the basic issues in this area and suggest some approaches that might be useful.
院士简介：
Robert E. Ricklefs 教授（院士）是国际著名的进化生物学家，美国科学院士。目前为美密苏里大学圣路易斯分校资深教授。
Ricklefs 教授在进化生态学，群落生态学，系统发育学，岛屿生物地理等多个领域取了非常显著的研究成果，已在Nature, Science, PNAS, Evolution，Systematic Biology, Ecology 等国际著名杂志上发表论文200余篇。
主页：http://www.umsl.edu/~ricklefsr/
Susanne S. Renner 教授（院士）是国际著名的进化植物学家，目前为德国慕尼黑大学全职教授, 兼任慕尼黑植物园主任, 慕尼黑植物标本馆主任和植物系统进化生物学会副主席，丹麦皇家科学院院士，巴伐利亚科学院院士(这是欧洲最高荣誉院士之一)， 德国科学院院士。
Renner 教授对有花植物的演化, 特别是在植物交配系统的演化, 传粉生物学和生物地理学等方面研究取得非常显著的成果；已在Nature, PNAS, Systematic Biology, Trends in Ecology & Evolution, Trends in Plant Science 等国际著名杂志上发表论文170余篇。
主页：http://www.umsl.edu/~renners/
联系人：罗世孝，电话：13631481358，邮箱：luoshixiao@scbg.ac.cn，华南植物园系统发育与繁殖生物学研究组
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