Woodworth L M, Montgomery M E, Nurthen R K, Briscoe D A, Frankham R
School of Biological Sciences, Macquarie University, Sydney, NSW, Australia.
Mol Ecol. 1994 Aug;3(4):393-9. doi: 10.1111/j.1365-294x.1994.tb00079.x.
Many natural populations fluctuate widely in population size. This is predicted to reduce effective population size, genetic variation, and reproductive fitness, and to increase inbreeding. The effects of fluctuating population size were examined in small populations of Drosophila melanogaster of the same average size, but maintained using either fluctuating (FPS) or equal (EPS) population sizes. FPS lines were maintained using seven pairs and one pair in alternate generations, and EPS lines with four pairs per generation. Ten replicates of each treatment were maintained. After eight generations, FPS had a higher inbreeding coefficient than EPS (0.60 vs. 0.38), a lower average allozyme heterozygosity (0.068 vs. 0.131), and a much lower relative fitness (0.03 vs. 0.25). Estimates of effective population sizes for FPS and EPS were 3.8 and 7.9 from pedigree inbreeding, and 4.9 vs. 7.1 from changes in average heterozygosities, as compared to theoretical expectations of 3.3 vs. 8.0. Results were generally in accordance with theoretical predictions. Management strategies for populations of rare and endangered species should aim to minimize population fluctuations over generations.
许多自然种群的种群数量波动很大。据预测，这会降低有效种群大小、遗传变异和繁殖适合度，并增加近亲繁殖。在平均大小相同的小群体黑腹果蝇中研究了种群数量波动的影响，这些群体通过波动种群大小（FPS）或相等种群大小（EPS）来维持。FPS系在交替世代中使用7对和1对来维持，EPS系每代使用4对。每种处理进行10次重复。八代后，FPS的近亲繁殖系数高于EPS（0.60对0.38），平均等位酶杂合度较低（0.068对0.131），相对适合度低得多（0.03对0.25）。根据系谱近亲繁殖，FPS和EPS的有效种群大小估计分别为3.8和7.9，根据平均杂合度变化分别为4.9对7.1，而理论预期分别为3.3对8.0。结果总体上符合理论预测。珍稀濒危物种种群的管理策略应旨在尽量减少世代间的种群波动。
