Hassall M, Walters R J, Telfer M, Hassall M R J
Centre for Ecology, Evolution and Conservation, School of Environmental Sciences, University of East Anglia, Norwich, UK.
J Evol Biol. 2006 Jan;19(1):267-76. doi: 10.1111/j.1420-9101.2005.00967.x.
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.
对来自不列颠群岛周围27个地点的田野蝗虫棕牧草蝗种群经过三代实验室培育的后代大小进行分析后发现，在该物种分布范围的西部和北部边界，向着更凉爽湿润的环境条件下，后代体型更大。这种变异具有显著的遗传成分。在种群之间和种群内部，产卵量和后代大小之间存在权衡。在适宜的温度和食物条件下，当个体产出最小卵的最大卵块时，母体适合度最佳，但在恶劣条件下，当个体产出非常大的后代的小卵块时，母体适合度最佳。对一段时间内几何平均适合度的计算表明，作为一种保守的风险分散策略，在分布范围边缘附近拥有更大的后代可能具有优势。除了卵大小的地理变异外，还观察到卵大小与温度相关的显著环境-基因型相互作用。
