Selection, patches and genetic variation: A cellular automaton modellingDrosophila populations
Selection, patches and genetic variation: A cellular automaton modellingDrosophila populations
复制标题
选择、补丁和遗传变异：果蝇种群的细胞自动机建模
DOI：
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发表时间：
1992
影响因子：
1.9
通讯作者：
B. Shorrocks
中科院分区：
文献类型：
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作者：
C. Dytham;B. Shorrocks
环境异质性促进遗传多样性的模型已经提出很多。这种模型描述了不同表型在不同类型斑块中具有不同适应值的情况，并且是生态学中允许物种共存的传统资源分配模型的遗传等价物。在这里，我们构建了一个不同类型的细胞模型，其中果蝇种群的多态性可以保持没有传统的资源分区。从实验室和现场观察中获得的参数值代表真菌育种果蝇。在描述斑块间的迁移时，采用了一定的随机性。在模型空间被划分成一个统一的矩阵的细胞，其中每一个都有可能包含一个短暂的资源项目（真菌子实体）。使用了多达400个细胞的方形竞技场。基因型到达一个新的地点，繁殖（哈代-温伯格平衡）和产卵。卵孵化和幼虫竞争使用Hassell-Comins竞争方程，好像他们是三个不同的物种。成虫均迁移到相邻的细胞中。在自然界中观察到的聚集模式是使用“吸引概率”产生的，其中每只苍蝇都有机会移动到当前人口最稠密的相邻补丁。这种对迁移的“黑匣子”描述产生的分布模式与真菌繁殖的果蝇野生种群中所见的分布模式无法区分。结果表明，“吸引概率”是维持多态性的关键因素，即使上级基因型的竞争优势很大，多态性也能维持。
SummaryMany models have been proposed in which environmental heterogeneity promotes genetic diversity. Such models describe the situation where different phenotypes have different fitness values in different types of patch and are the genetic equivalent of the traditional resource partitioning models in ecology which allow the coexistence of species. Here we construct a different type of cellular model in which polymorphisms in populations ofDrosophila can be maintained without traditional resource partitioning. Parameter values taken from laboratory and field observations represent fungal breedingDrosophila. Some stochasticity is used in the description of the migration between patches. In the model space is divided into a uniform matrix of cells each of which has the potential to contain an ephemeral resource item (fungal fruiting body). Square arenas of up to 400 cells were used. Genotypes arrive at a fresh site, breed (Hardy-Weinberg equilibrium) and lay eggs. The eggs hatch and the larvae compete using the Hassell-Comins competition equations, as if they were three different species. Adult emergents all migrate to an adjacent cell. The aggregation patterns observed in nature are produced using an ‘attraction probability’ where each fly has a chance of moving to the currently most densely populated adjacent patch. This ‘black box’ description of migration produces distribution patterns which are indistinguishable from those seen in wild populations of fungal breedingDrosophila. Results show that the ‘attraction probability’ is the key factor in the maintenance of polymorphism and that even when the competitive advantage of the superior genotype is very great, polymorphisms can be maintained.