| Project/Area Number |
05454011
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
生態
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| Research Institution | National Institute Environmental Studies |
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Principal Investigator |
TSUBAKI Yoshitaka National Institute for Environmental Studies, Global Environment Research Group, Head Researcher, 地球環境研究グループ, 総合研究官 (30108641)
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| Co-Investigator(Kenkyū-buntansha) |
TOMIYAMA Kiyonori Ibaraki University, Faculty of Science, Assistant Professor, 理学部, 助手 (30272107)
NAGATA Hisashi National Institute for Environmental Studies, Global Environment Research Group,, 地球環境研究グループ, 主任研究員 (00202226)
TAKAMURA Kenzi National Institute for Environmental Studies, Global Environment Research Group,, 地球環境研究グループ, 主任研究員 (40163315)
冨山 清升 国立環境研究所, 地球環境研究グループ, 主任研究員
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| Project Period (FY) |
1993 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥4,900,000 (Direct Cost: ¥4,900,000)
Fiscal Year 1995: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1994: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1993: ¥2,400,000 (Direct Cost: ¥2,400,000)
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| Keywords | wildlife / genetic variability / fluctuating asymmetry / natural selection / sexual selection / conservation biology / population / viability |
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| Research Abstract |
Genetic stochasticity is one of many potential causes of extinction in samall populations. The objects of this research is to know how genetic variability changes according to the reduction of population size or habitat destruction, and how the decrease in genetic variability influences the reproductive output of animals.
In the process of population decrease, populations may suffer a significant genetic deterioration, namely a decrease in genetic variability, which may lead to a corresponding decrease in fitness (survival and reproduction). As Fitness can often be measured as fluctuating asymmetry (FA), we analyzed FA in relation to various fitness-related characters, such as survival growth rate, territoriality and/or reproductive success in several animals. We found negative correlation between mating success and FA in insects including dragonflies, butterflies and midges. FA measurements on several passerine birds revealed that population density and the distribution ranges were negatively correlated with population mean of FA.
FA may be influenced both by genetic and environmental stresses. We tested the effect of density on the growth and FA of a fish (Oryzias latipes). As a result, we detected density effects on average growth rate but not on FA.This suggests that a genetic effect is more important in the mediation of FA than density (environmental) effect at least in this species.
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