Why does a grasshopper have fewer, larger offspring at its range limits?
Why does a grasshopper have fewer, larger offspring at its range limits?
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DOI：
10.1111/j.1420-9101.2005.00967.x
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发表时间：
2006-01-01
影响因子：
2.1
通讯作者：
Hassall, MRJ
中科院分区：
文献类型：
--
作者：
Hassall, M;Walters, RJ;Hassall, MRJ
通过三个实验室世代饲养的后代的大小分析表明，后代对凉爽潮湿的条件下，西部和北方的范围内的限制，从27个网站周围的不列颠群岛的田间蝗虫的棕色雏蝗种群。这种变异具有显著的遗传成分。种群间和种群内窝卵数和子代大小之间存在权衡关系。在有利的热和喂养条件下，产妇健身是最佳的个人生产最大的离合器最小的鸡蛋，但在恶劣的条件下，产妇健身是最佳的个人生产小离合器非常大的后代。随着时间的推移，几何平均适应度的计算表明，有较大的后代接近范围的边缘可能是有利的，作为一个保守的风险分散策略。以及在鸡蛋大小的地理变异，显着的环境基因型相互作用，鸡蛋大小与温度的关系进行了观察。
Analysis of size of offspring reared through three laboratory generations from populations of the field grasshopper Chorthippus brunneus from 27 sites around the British Isles showed that offspring were larger towards the cooler-wetter conditions in the western and northern limits of the range. This variation had a significant genetic component. There was a trade-off between clutch size and offspring size between and within populations. Under favourable thermal and feeding conditions maternal fitness was optimal when individuals produced the largest clutches of the smallest eggs, but under poor conditions maternal fitness was optimal when individuals produced small clutches of very large offspring. Calculation of geometric mean fitness over time indicated that having larger offspring near to the edge of the range could be advantageous as a conservative risk-spreading strategy. As well as geographic variation in egg size, significant environment-genotype interactions in egg size in relation to temperature were observed.