Abstract
Allozymic variation encoded by 26 loci was analyzed electrophoretically in 507 specimens representing 12 populations of green toads, Bufo viridis, in Israel and the Vis Adriatic Island. Genetic variation in Bufo viridis is higher than in any vertebrate yet studied. Mean heterozygosity per locus per individual (H) is 0.133 (range, 0.105 to 0.159). H is higher in central populations as compared with isolates, and varies among four major protein classes, being highest in transferases and hydrolases and lowest in oxidoreductases and nonenzymatic proteins. Differential gene frequencies among polymorphisms was tested as an indicator of natural selection. Significant heterogeneity between loci in their apparent inbreeding coefficients Fe=S-2p/P(1-p) was found for all alleles and for each of the four major classes of proteins tested, which may be taken as evidence of selection. Both uniform and diversifying selection are suggested by the low and high Fe values, respectively. The general pattern of high heterozygosity in Bufo viridis is best explained as an adaptive strategy in heterogeneous environments.
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Selected References
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- Cavalli-Sforza L. L. Population structure and human evolution. Proc R Soc Lond B Biol Sci. 1966 Mar 22;164(995):362–379. doi: 10.1098/rspb.1966.0038. [DOI] [PubMed] [Google Scholar]
- Levinton J. Genetic variation in a gradient of environmental variability: marine bivalvia (Mollusca). Science. 1973 Apr 6;180(4081):75–76. doi: 10.1126/science.180.4081.75. [DOI] [PubMed] [Google Scholar]
- Lewontin R. C., Krakauer J. Distribution of gene frequency as a test of the theory of the selective neutrality of polymorphisms. Genetics. 1973 May;74(1):175–195. doi: 10.1093/genetics/74.1.175. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nevo E., Shaw C. R. Genetic variation in a subterranean mammal, Spalax ehrenbergi. Biochem Genet. 1972 Dec;7(3):235–241. doi: 10.1007/BF00484821. [DOI] [PubMed] [Google Scholar]
- Nevo E. Test of selection and neutrality in natural populations. Nature. 1973 Aug 31;244(5418):573–575. doi: 10.1038/244573a0. [DOI] [PubMed] [Google Scholar]