| 项目编号: | 1403034
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| 项目名称: | DISSERTATION RESEARCH: Spatial sorting and Postglacial population dynamics in Plethodon dunni and P. vehiculum. |
| 作者: | Bryan Carstens
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| 承担单位: | Ohio State University
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| 批准年: | 2013
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| 开始日期: | 2014-06-01
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| 结束日期: | 2016-05-31
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| 资助金额: | USD20016
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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: | researcher
; spatial sorting hypothesis
; spatial sorting
; dispersal ability
; expansion
; population
; single refugial population
; population expansion
; additional research
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| 英文摘要: | While natural selection is a well-characterized evolutionary force, it may not be the only mechanism for evolutionary change -- particularly during rapid evolutionary adaptations occurring in some populations. In species that experience rapid expansion of their geographic range, it is hypothesized that those individuals with phenotypic traits that enhance dispersal ability will represent the leading edge of the expansion, and will mate with individuals that possess similar traits. In theory, this assortative mating should lead to the evolution of traits associated with enhanced dispersal ability. This project will test this "spatial sorting hypothesis" in two closely related species of salamanders. These two salamander species have limited dispersal abilities, were restricted to southern refugial ranges during the last glacial maximum, and have been expanding to the north at different rates for the last 20,000 years. The researchers will collect genetic, environmental, and morphological data that will allow them to measure rates of expansion, determine if expansion is ongoing, and identify the traits that are evolving due to spatial sorting. More broadly, an enhanced understanding of range evolution in response to a warming climate will have important implications for the conservation of temperate species.
This project focuses on an ideal system for testing the spatial sorting hypothesis. Spatial sorting is expected to occur during sudden range expansions, when fast-dispersing individuals at the margins of an expanding species are spatially segregated, and thus reproduce with similar individuals. Once the range expansion reaches its limits (set by environmental conditions or available habitat), the assortative mating that produced spatially-sorted phenotypes will cease, and random mating will return throughout the population. Documentation of spatial sorting thus requires a system where phenotypes associated with dispersal can be quantified and where expansion has not reached its limit. The proposed work will quantify such phenotypes in a system where population expansion is ongoing and dispersal rates are low. Preliminary genetic data collected by the researchers indicate that the two focal species were confined to a single refugial population at the close of the last glacial maximum and species distribution modeling (SDM) suggests that this refuge was located in southern Oregon. The researchers will conduct additional research to identify any suitable habitat that is unoccupied and to refine the location of glacial refugia and expansion routes. The researchers will measure phenotypic traits associated with dispersal ability and measure direct dispersal via mark-recapture methods, ultimately quantifying evidence to support or refute the spatial sorting hypothesis. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/96791
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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: | |
Bryan Carstens. DISSERTATION RESEARCH: Spatial sorting and Postglacial population dynamics in Plethodon dunni and P. vehiculum.. 2013-01-01.
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