A separation-of-timescales approach to the coalescent in a continuous population
A separation-of-timescales approach to the coalescent in a continuous population
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DOI：
10.1534/genetics.103.022830
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发表时间：
2004-12-01
期刊：
影响因子：
3.3
通讯作者：
Wilkins, JF
中科院分区：
文献类型：
--
作者：
Wilkins, JF
本文对连续二维栖息地中的距离隔离模型进行了分析。推导了从矩形栖息地的特定位置采样的一对序列的合并时间分布的近似表达式。结果在质量上与之前的距离隔离分析相似，但明确说明了样本相对于栖息地边界的位置。时间尺度分离方法利用了采样位置仅影响最近的合并行为这一事实。当种群规模大于谱系跨越栖息地范围所需的代数时，金曼的合并时间可以通过有效种群规模重新调整的时间来合理地描述长期谱系过程。这种长期有效种群规模受到当地分散行为以及栖息地几何形状的影响。当种群规模小于穿越栖息地所需的时间时，谱系中的深层分支比标准中性合并下的预期更长，类似于过去种群规模较大的恐慌种群的预期模式。
This article presents an analysis of a model of isolation by distance in a continuous, two-dimensional habitat. An approximate expression is derived for the distribution of coalescence times for a pair of sequences sampled from specific locations in a rectangular habitat. Results are qualitatively similar to previous analyses of isolation by distance, but account explicitly for the location of samples relative to the habitat boundaries. A separation-of-timescales approach takes advantage of the fact that the sampling locations affect only the recent coalescent behavior. When the population size is larger than the number of generations required for a lineage to cross the habitat range, the long-term genealogical process is reasonably well described by Kingman's coalescent with time rescaled by the effective population size. This long-term effective population size is affected by the local dispersal behavior as well as the geometry of the habitat. When the population size is smaller than the time required to cross the habitat, deep branches in the genealogy are longer than would be expected under the standard neutral coalescent, similar to the pattern expected for a panmictic population whose population size was larger in the past.