Stow A J, Sunnucks P
Department of Biological Sciences, Macquarie University, NSW 2109 Australia.
Mol Ecol. 2004 Feb;13(2):443-7. doi: 10.1046/j.1365-294x.2003.02060.x.
Habitat fragmentation/alteration has been proposed as a distinct process threatening the viability of populations of many organisms. One expression of its impact may be the disruption of core population processes such as inbreeding avoidance. Using the experimental design outlined in our companion paper, we report on the impact of habitat alteration (deforestation) on inbreeding in the rock-dwelling Australian lizard Egernia cunninghami. Ten microsatellite loci were used to calculate relatedness coefficients of potential and actual breeding pairs, and to examine mate-choice and heterozygosity. Despite significantly less dispersal and higher within-group relatedness between potential mates in deforested than in natural habitats, this did not result in significantly more inbred matings. Average relatedness amongst breeding pairs was low, with no significant difference between natural and fragmented populations in relatedness between breeding pairs, or individual heterozygosity. Active avoidance of close kin as mates was indicated by the substantially and significantly lower relatedness in actual breeding pairs than potential ones. These facts, and heterozygote excesses in all groups of immature lizards from both habitats, show that E. cunninghami maintained outbreeding in the face of increased accumulation of relatives.
栖息地破碎化/改变已被认为是一个威胁许多生物种群生存能力的独特过程。其影响的一种表现可能是核心种群过程的中断，比如近亲繁殖回避。利用我们配套论文中概述的实验设计，我们报告了栖息地改变（森林砍伐）对栖息于岩石的澳大利亚蜥蜴坎宁安氏石龙子近亲繁殖的影响。使用10个微卫星位点来计算潜在和实际繁殖对的亲缘系数，并研究配偶选择和杂合性。尽管与自然栖息地相比，森林砍伐地区潜在配偶之间的扩散显著减少且群体内亲缘关系更高，但这并未导致近亲繁殖交配显著增加。繁殖对之间的平均亲缘关系较低，自然种群和破碎化种群之间在繁殖对的亲缘关系或个体杂合性方面没有显著差异。实际繁殖对比潜在繁殖对的亲缘关系大幅且显著更低，这表明存在对近亲作为配偶的主动回避。这些事实，以及来自两个栖息地的所有未成熟蜥蜴群体中的杂合子过剩，表明坎宁安氏石龙子在亲属积累增加的情况下仍保持远交。
