The maintenance of genetic polymorphism in small island populations: Large mammals in the Hebrides

被引:38
作者
Pemberton, JM
Smith, JA
Coulson, TN
Marshall, TC
Slate, J
Paterson, S
Albon, SD
CluttonBrock, TH
机构
[1] UNIV CAMBRIDGE, DEPT GENET, CAMBRIDGE CB2 3EH, ENGLAND
[2] ZOOL SOC LONDON, INST ZOOL, LONDON NW1 4RY, ENGLAND
[3] UNIV CAMBRIDGE, DEPT ZOOL, CAMBRIDGE CB2 3EJ, ENGLAND
关键词
D O I
10.1098/rstb.1996.0069
中图分类号
Q [生物科学];
学科分类号
07 ; 0710 ; 09 ;
摘要
Conventionally, small populations living on islands are expected to lose genetic variation by drift. Fluctuations in population size, combined with polygynous mating systems, are expected to contribute to the process by increasing sampling effects on genetic variation. However, in individually monitored populations of Red deer on Rum and Soay sheep on St. Kilda, which experience fluctuations in population size, two processes have been identified which mitigate loss of genetic variation. First, in a number of examples, population reductions are associated with selection. Selection may be in favour of heterozygotes, or, as we have documented in several cases, it may fluctuate in direction temporally. Second, in Soay sheep, in which mortality over population crashes is male-biased, ostensibly leading to low effective numbers of males, molecular studies show that there are systematic changes in the reproductive success of young males, and in variance in male success, that broaden genetic representation compared with expectation.
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页码:745 / 752
页数:8
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