THE EVOLUTION OF OFFSPRING SIZE AND NUMBER - A TEST OF THE SMITH-FRETWELL MODEL IN 3 SPECIES OF CRICKETS
THE EVOLUTION OF OFFSPRING SIZE AND NUMBER - A TEST OF THE SMITH-FRETWELL MODEL IN 3 SPECIES OF CRICKETS
复制标题
DOI：
10.1007/bf00329806
复制
发表时间：
1995-06-01
期刊：
影响因子：
2.7
通讯作者：
ROFF, DA
中科院分区：
文献类型：
--
作者：
CARRIERE, Y;ROFF, DA
大多数亲本对后代的投资模型都假设繁殖体大小和数量之间存在权衡，以及将后代适应度与繁殖体大小相关的不断增加的“下凹”函数。在这项研究中，我们使用三种密切相关的蟋蟀物种（Gryllusfirmus、G.veletis 和 G.pennsylvanicus）来测试这两个基本假设。估算了每个物种种群的卵重、35 天繁殖力和 35 天卵生物量，并估算了这些繁殖性状与产卵日期和体型之间的关系。还研究了埋藏在不同深度、土壤湿度和土壤类型（G.firmus 和 G.veletis）以及田间（G.pennsylvanicus）的蛋的蛋重和后代存活率之间的关系。考虑到物种间蛋重和体型的差异，多变量分析揭示了蛋重和 35 天繁殖力之间的权衡。与影响卵的环境条件无关，从土壤中出现的幼虫数量与每个物种的繁殖体重量之间存在正相关关系。因此，这些发现为上述模型中考虑的假设提供了部分支持。在可推导出蛋重与幼虫存活相关函数的三组条件中的两组中，单一最佳蛋大小受到青睐。然而，卵所遇到的条件会影响幼虫的平均存活率，以及卵重和后代存活率之间关系的形状。这表明蟋蟀蛋经常面临着蛋和幼体生存的异质环境。考虑了栖息地异质性对最佳蛋大小进化的影响。在生态和进化背景下讨论了生殖成分与雌性年龄和体型之间的关系，以及卵大小与蟋蟀生活史变化之间的关系。
Most models of parental investment in offspring assume a trade-off between propagule size and number, and an increasing ''concave down'' function relating offspring fitness to propagule size. In this study, we test these two fundamental assumptions, using three closely related species of crickets, Gryllus firmus, G. veletis, and G. pennsylvanicus. Egg weight, 35-day fecundity and 35-day egg biomass were estimated in a population of each species, and the relationships between these reproductive traits and date of egg laying and body size were estimated. The relationships between egg weight and offspring survival were also sought for eggs buried at different depths, soil moistures, and soil types (G. firmus and G. veletis), as well as in the field (G. pennsylvanicus). A trade-off between egg weight and 35-day fecundity was revealed in a multivariate analysis taking into account among-species variation in egg weight and body size. Independent of the environmental conditions affecting the eggs, a positive correlation existed between the number of larvae that emerged from the soil and propagule weight in each species. Therefore, these findings provide partial support for the assumptions considered in the models mentioned above. A single optimal egg size was favored in two out of the three sets of conditions in which the functions relating egg weight to larval survival could be derived. The conditions encountered by the eggs, however, influenced the average survival of the larvae, as well as the shape of the relationship between egg weight and offspring survival. This suggests that cricket eggs frequently face heterogeneous environments with respect to egg and hatchling survival; the implication of habitat heterogeneity on the evolution of an optimal egg size is considered. The relationships between the reproductive components and female age and size, as well as between egg size and variation in cricket life-history, are discussed in an ecological and evolutionary context.