The phenomology of niche evolution via quantitive traits in a 'black-hole' sink
The phenomology of niche evolution via quantitive traits in a 'black-hole' sink
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DOI：
10.1098/rspb.2002.2219
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发表时间：
2003-01-22
影响因子：
4.7
通讯作者：
Barfield, M
中科院分区：
文献类型：
--
作者：
Holt, RD;Gomulkiewicz, R;Barfield, M
以前的适应性进化的研究在汇生境（其中一个物种的孤立的人口不能持续确定性）强调了人口的限制，在减缓这种演变的重要性，和移民在促进适应。这些研究依赖于单位点模型或确定性定量遗传公式。我们使用基于个人的模拟研究适应性进化的“黑洞”水槽环境中，健身是由一个多基因字符。模拟跟踪个人的数量和他们的多位点基因型，并纳入，在一个自然的方式，人口和遗传随机过程。与以前的研究一致，我们的研究结果揭示了人口限制和移民在水槽内适应中所起的核心作用（在绝对适应度低的环境中适应更加困难，更高的移民可以加速适应）。一个新的发现是，在水槽环境中的适应性进化中存在一种“标点”模式。种群通常在很长一段时间内保持不适应状态，然后迅速转变为相对适应的状态，在这种状态下，持久性不再依赖于经常性移民。
Previous studies of adaptive evolution in sink habitats (in which isolated populations of a species cannot persist deterministically) have highlighted the importance of demographic constraints in slowing such evolution, and of immigration in facilitating adaptation. These studies have relied upon either single-locus models or deterministic quantitative genetic formulations. We use individual-based simulations to examine adaptive evolution in a 'black-hole' sink environment where fitness is governed by a polygenic character. The simulations track both the number of individuals and their multi-locus genotypes, and incorporate, in a natural manner, both demographic and genetic stochastic processes. In agreement with previous studies, our findings reveal the central parts played by demographic constraints and immigration in adaptation within a sink (adaptation is more difficult in environments with low absolute fitness, and higher immigration can accelerate adaptation). A novel finding is that there is a 'punctuational' pattern in adaptive evolution in sink environments. Populations typically stay maladapted for a long time, and then rapidly shift into a relatively adapted state, in which persistence no longer depends upon recurrent immigration.