Population Genomics of Secondary Contact
Population Genomics of Secondary Contact
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DOI：
10.3390/genes1010124
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发表时间：
2010-06-01
期刊：
影响因子：
3.5
通讯作者：
Garrigan, Daniel
中科院分区：
文献类型：
--
作者：
Geneva, Anthony;Garrigan, Daniel
一种常见的网状进化形式是由于先前异地种群之间的二次接触而产生的。使用广泛的合并模拟，我们描述的条件和程度，遗传物质的基因渗入到一个殖民人口的基因组从一个地方性的人口。从描述整个染色体进化的模型中对模拟的结合历史进行采样，从而允许估计渗入单倍型的预期长度。结果表明，我们的能力，以确定网状进化的遗传数据是高度可变的，并严重依赖于持续时间的时期的异地，二次接触事件的时间，以及在接触时的人口规模。一个特别有趣的结果是，当二次接触发生在接近严重创始人事件的时间时，在这种情况下，基因渗入可能更难检测。然而，如果在这样的建立事件之后发生二次接触，当定殖群体的范围增加时，在整个基因组中更容易检测到基因渗入。这一结果可能对我们检测具有祖先血缘关系的现代人类种群和古老的人类物种（如尼安德特人）之间的基因渗入的能力具有重要意义。
One common form of reticulate evolution arises as a consequence of secondary contact between previously allopatric populations. Using extensive coalescent simulations, we describe the conditions for, and extent of, the introgression of genetic material into the genome of a colonizing population from an endemic population. The simulated coalescent histories are sampled from models that describe the evolution of entire chromosomes, thereby allowing the expected length of introgressed haplotypes to be estimated. The results indicate that our ability to identify reticulate evolution from genetic data is highly variable and depends critically upon the duration of the period of allopatry, the timing of the secondary contact event, as well as the sizes of the populations at the time of contact. One particularly interesting result arises when secondary contact occurs close to the time of a severe founder event, in this case, genetic introgression can be substantially more difficult to detect. However, if secondary contact occurs after such a founding event, when the range of the colonizing population increases, introgression is more readily detectable across the genome. This result may have important implications for our ability to detect introgression between ancestrally bottlenecked modern human populations and archaic hominin species, such as Neanderthals.