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[F-3.1.3 Studies on Survival and Reproduction of Animals in Relation to Genetic Variability]

[Contact Person]

Yoshitaka Tsubaki
Global Environment Division, National Institute for
Environmental Study, Environmental Agency.
Onogawa 16-2, Tsukuba, Ibaraki, 305 Japan
Tel:+81-298-50-2482 Fax:+81-298-51-4732
E-mail: tsubaki@nies.go.jp

[Total Budget for FY1993-1995]

23,113,000 Yen (FY1995 6,659 ,000 Yen)

[Abstract]

　Genetic stochasticity is one of many potential causes of extinction in small populations. Objects of this research are 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 analysed 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.

[Key Words]

small population, genetic variability, fitness, fluctuating asymmetry