Stow A J, Sunnucks P, Briscoe D A, Gardner M G
Department of Biological Sciences, Macquarie University, NSW 2109, Australia.
Mol Ecol. 2001 Apr;10(4):867-78. doi: 10.1046/j.1365-294x.2001.01253.x.
The effects of habitat fragmentation on processes within and among populations are important for conservation management. Despite a broad spectrum of lifestyles and the conservation significance of many reptiles, very little work on fine-scale population genetics has been carried out on this group. This study examines the dispersal patterns of a rock crevice-dwelling lizard, Cunningham's skink (Egernia cunninghami), in a naturally vegetated reserve and an adjacent deforested site. Both genotypic and genic approaches were employed, using microsatellite loci. The spatial organization of individuals with respect to pairwise relatedness coefficients and allele frequencies, along with assignment tests, were used to infer dispersal characteristics for both sexes in a natural and a cleared area. The distribution of relatedness in both habitats was spatially structured, with E. cunninghami showing high pairwise relatedness within their rocky retreat sites. Analysis of relatedness over different spatial scales, spatial autocorrelation of alleles and assignment tests, all indicated that both sexes in the cleared area show less dispersal than their counterparts in the reserve. Furthermore, deforestation may inhibit female dispersal to a greater extent than that of males. The geographical structuring of allele frequencies for adults in the cleared area, but not the reserve, indicates that habitat fragmentation has the potential to alter at least the microevolution of E. cunninghami populations.
栖息地破碎化对种群内部和种群之间过程的影响，对于保护管理而言至关重要。尽管许多爬行动物具有广泛的生活方式和保护意义，但针对这一类群在精细尺度种群遗传学方面的研究却很少。本研究调查了一种栖息于岩石缝隙的蜥蜴——坎宁安石龙子（Egernia cunninghami）在一个自然植被保护区和相邻砍伐森林区域的扩散模式。研究采用了基因型和基因分型方法，利用微卫星位点进行分析。通过个体间成对亲缘系数和等位基因频率的空间组织，以及分配测试，来推断自然区域和砍伐区域中两性的扩散特征。两个栖息地中亲缘关系的分布在空间上具有结构性，坎宁安石龙子在其岩石避难所内呈现出较高的成对亲缘关系。对不同空间尺度上的亲缘关系分析、等位基因的空间自相关分析以及分配测试均表明，砍伐区域内的两性扩散程度均低于保护区内的同类个体。此外，森林砍伐对雌性扩散的抑制作用可能比对雄性的抑制作用更大。砍伐区域内成年个体等位基因频率的地理结构差异（保护区内未出现这种情况）表明，栖息地破碎化至少有可能改变坎宁安石龙子种群的微观进化。
