Departamento de Producción Animal, ETS Ingenieros Agrónomos, Universidad Politécnica de Madrid, Ciudad Universitaria, Spain.
Animal. 2011 Sep;5(11):1669-83. doi: 10.1017/S1751731111000498.
Genetic variation is vital for the populations to adapt to varying environments and to respond to artificial selection; therefore, any conservation and development scheme should start from assessing the state of variation in the population. There are several marker-based and pedigree-based parameters to describe genetic variation. The most suitable ones are rate of inbreeding and effective population size, because they are not dependent on the amount of pedigree records. The acceptable level for effective population size can be considered from different angles leading to a conclusion that it should be at least 50 to 100. The estimates for the effective population size can be computed from the genealogical records or from demographic and marker information when pedigree data are not available. Marker information could also be used for paternity analysis and for estimation of coancestries. The sufficient accuracy in marker-based parameters would require typing thousands of markers. Across breeds, diversity is an important source of variation to rescue problematic populations and to introgress new variants. Consideration of adaptive variation brings new aspects to the estimation of the variation between populations.
遗传变异对于种群适应不同环境和应对人工选择至关重要；因此，任何保护和发展计划都应从评估种群的变异状况开始。有几种基于标记和系谱的参数可用于描述遗传变异。最合适的参数是近交系数和有效种群大小，因为它们不依赖于系谱记录的数量。有效种群大小的可接受水平可以从不同角度考虑，得出的结论是它至少应该在 50 到 100 之间。当没有系谱数据时，可以从系谱记录或从人口统计和标记信息中计算有效种群大小的估计值。标记信息也可用于父系分析和估算共同祖先。基于标记的参数具有足够的准确性，需要对数千个标记进行分型。在不同品种之间，多样性是拯救有问题的种群和引入新变体的重要变异来源。对适应性变异的考虑为种群之间的变异估计带来了新的方面。
