| 项目编号: | 1406952
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| 项目名称: | DISSERTATION RESEARCH: Genetic Basis and Adaptive Significance of Key Developmental Traits Underlying Ecological Differences Between Sympatric Sister Species |
| 作者: | John Willis
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| 承担单位: | Duke University
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| 批准年: | 2013
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| 开始日期: | 2014-05-15
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| 结束日期: | 2017-10-31
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| 资助金额: | USD20322
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| 资助来源: | US-NSF
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| 项目类别: | Standard Grant
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| 国家: | US
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| 语种: | 英语
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| 特色学科分类: | Biological Sciences - Environmental Biology
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| 英文关键词: | species
; ecological difference
; difference
; flowering time difference
; single species
; project
; reproductive isolation incipient species
; ecological trait difference
; ecological divergence
; related sympatric species
; related species
; quantitative trait locus
; sympatric species
; genetic difference
; different genetic basis
; rare sister species mimulus nudatus co-occur
; species coexistence
; several trait
; ecological differentiation intense competition
; species biodiversity
; rare endemic species
; species interaction
; widespread species
; ecological similarity
; co-occur
; ecological differentiation
; western north american wildflower species
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| 英文摘要: | Most species are formed when geographic barriers physically separate populations for long periods of time. For species to remain distinct once they are in contact with one another they must evolve reproductive isolation often through ecological differentiation. Without reproductive isolation incipient species will hybridize and fuse back together into a single species. Without ecological differentiation intense competition will often cause one species to go locally extinct. Species that presently co-occur may have evolved ecological differences while physically separated, or they may have evolved differences in the same area through selection to minimize hybridization or competition. Little is known about the ecological trait differences that allow species to coexist in the same area or the genetic loci responsible for ecological differences between species. This study will identify the traits and genetic loci underlying ecological differences that enable coexistence between two western North American wildflower species. The broadly distributed Mimulus guttatus, and its relatively rare sister species Mimulus nudatus co-occur in some areas but live in distinct microhabitats that differ in the onset of summer drought. Mimulus nudatus grows on serpentine slopes that dry out early in the spring, while M. guttatus inhabits ephemeral streams where drought imposed death is later than in the M. nudatus habitat. The rare endemic possesses several traits that are likely adaptations to earlier drought, including a shorter critical photoperiod to induce flowering resulting in an earlier production of a flowering shoot (bolting) and an earlier flowering time than the more common M. guttatus. Understanding how rare endemic species are maintained with more widespread species has important implications for conservation and the preservation of biodiversity. Determining the underlying genetic changes to enable species coexistence will shed light on the interaction among genetic, ecological, and evolutionary processes that contribute to the maintenance of species biodiversity. This project will maintain and develop new mentoring opportunities targeting underrepresented groups at the middle school, high school, and undergraduate level. The results of the proposed research will be broadly disseminated though talks and publications to the public and scientific community.
This project will explicitly test the ecological and evolutionary forces maintaining spatial, phenotypic and genetic differences between two closely related species of Mimulus. Ecological similarity between sympatric species may lead to competitive exclusion. Consequently, ecological divergence is a necessary prerequisite for stable coexistence. Differences in flowering time between the common M. guttatus and the rare endemic M. nudatus are hypothesized to allow these species to occur in sympatry by inhabiting distinct microhabitats that differ in the onset of summer drought. Three quantitative trait loci (QTL) have been identified that profoundly influence differences in critical photoperiod and bolting and have already been genetically mapped, yet we do not know how these loci contribute to microhabitat differentiation and species interactions in nature. This project will utilize QTL mapping, reciprocal transplant and competition experiments to test: (1) whether flowering time differences in the field have the same or different genetic basis from photoperiod and bolting in the lab, (2) whether photoperiod and bolting loci are adaptive and enable coexistence by contributing to niche differentiation, and (3) whether ecological or reproductive character displacement are responsible for flowering time differences in the two closely related sympatric species. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/96908
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| Appears in Collections: | 影响、适应和脆弱性
气候减缓与适应
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| Recommended Citation: | |
John Willis. DISSERTATION RESEARCH: Genetic Basis and Adaptive Significance of Key Developmental Traits Underlying Ecological Differences Between Sympatric Sister Species. 2013-01-01.
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