| 项目编号: | 1655727
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| 项目名称: | Evolutionary adaptation to intensifying drought across a geographic gradient: a comprehensive evaluation of Fisher's Fundamental Theorem |
| 作者: | Susan Mazer
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| 承担单位: | University of California-Santa Barbara
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| 批准年: | 2017
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| 开始日期: | 2017-08-01
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| 结束日期: | 2021-07-31
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| 资助金额: | 778809
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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: | adaptation
; population
; reproduction
; drought-tolerance
; first rigorous evaluation
; natural environmental gradient
; fundamental theorem
; genetic variation
; empirical evaluation
; aridity gradient
; environmental gradient
; trait
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| 英文摘要: | This project will test long-standing evolutionary theory about how rapidly populations can adapt to changing environments by investigating rates of adaptation to intensifying drought in a wild, flowering plant native to California, commonly known as baby blue eyes. The ability of populations to adapt to stressful environmental conditions depends on the presence of genetic variation in survival and reproduction, as well as a genetic variation in the traits that affect survival and reproduction, such as plant physiology and timing of reproduction. Very few studies have measured the process of adaptation to identify the factors that determine how rapidly plant populations adapt to water-limited conditions, in nature. This research will integrate measures of: (1) genetic variation in plant survival and reproduction, both within and among natural populations, as well as in the traits that contribute to plant performance; (2) natural selection in wild populations; and (3) changes between generations in the genetically based aspects of survival and reproduction. Statistical models based on evolutionary theory will be used to predict the magnitude of adaptive change that should occur in each study population. These predictions will be compared to the actual change in survivoral and reproduction observed between generations. Undergraduate students in under-represented groups will be recruited to participate in this research through the Ecological Society of America, the American Indian Science and Engineering Society, and the Society for the Advancement of Chicano and Native Americans in Science. These students will be trained in the design, implementation, and analysis of genetic data collected from field and breeding experiments. Cooperative relationships will be built with the Environmental and Lands departments of Tribal communities, and workshops will be offered to local communities to inform them of the goals, methods, and outcomes of this research.
Many studies of plant species have detected plastic responses of phenological or morphological traits to experimentally induced or natural environmental variation, or changes in the strength or direction of phenotypic selection in populations occupying different environments. To date, however, no studies have assessed evolutionary change between generations, in real time, across natural environmental gradients with respect to phenological, morphological, and physiological traits. This study will combine detailed studies of geographic variation in fitness-related traits among populations of a widespread herb (Nemophila menziesii, Hydrophyllaceae) with measures of: phenotypic selection on traits that contribute to drought-tolerance; inter-generational change in additive genetic variance in fitness; and the response to selection in order to test predictions regarding adaptation to environmental conditions across an aridity gradient. Aster models will be used to estimate additive genetic variance in individual fitness in pedigreed populations under field conditions and to estimate the strength and direction of selection on phenological, morphological, and physiological traits. These models will facilitate the empirical evaluation of the accuracy of Fisher's Fundamental Theorem of Natural Selection (FFT), which predicts that the rate of change in population mean fitness should equal the ratio of additive genetic variance in fitness to mean absolute fitness. This ratio represents a population's capacity to adapt to current conditions, or its "adaptive capacity". This project will be the first rigorous evaluation of FFT in wild populations across an environmental gradient. This study will contribute to the understanding of how natural selection operates across a species' range, potentially identifying mechanisms, such as the existence of multiple combinations of traits associated with fitness optima, that promote the maintenance of genetic variation in wild populations. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/89595
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| Appears in Collections: | 全球变化的国际研究计划
科学计划与规划
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| Recommended Citation: | |
Susan Mazer. Evolutionary adaptation to intensifying drought across a geographic gradient: a comprehensive evaluation of Fisher's Fundamental Theorem. 2017-01-01.
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