Gambling on grandchildren: do aphids hedge their bets?

赌孙辈：蚜虫会两面下注吗？

• 批准号: NE/G009805/1
• 负责人: David Hodgson
• 金额: $ 5.34万
• 依托单位: UNIVERSITY OF EXETER
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2009
• 资助国家: 英国
• 起止时间: 2009 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FG009805%2F1
• 关键词: Gambling; grandchildren; do; aphids; hedge

All organisms live in an uncertain world, and must prepare their offspring for survival in the face of this variation. In order to ensure that at least some offspring survive to reproduce, several tactics are available to mothers. (i) Pessimism: mothers may invest more resources than are normally required, just in case times are hard. (ii) Plasticity: mothers may provide offspring with the ability to change phenotype according to the prevailing environmental conditions. (iii) Bet hedging (or risk spreading): mothers may produce offspring with a variety of phenotypes, in the hopes that at least some of them survive to reproduce. The concept of bet hedging has received a great deal of support in organisms whose offspring emerge in different seasons: in this scenario, the non-intuitive outcome is that increasing the variability of ones offspring can reduce the variance in their future success, thus benefitting fitness and causing heritable bet hedging behaviour to spread through populations. This glamorous explanation has also been applied to organisms whose offspring experience unpredictable spatial variation within a season. However, such WITHIN generation bet hedging is actually very difficult to evolve. Between generation bet hedging works because offspring of a certain phenotype all experience the same environment. Within generation bet hedging only works in VERY small populations, because there is no correlation between environment and phenotype. Aphids have been promoted as a classic example of within-generation bet hedging. When aphid mothers produce unwinged offspring, they give them a uniform number of ovarioles (reproductive investment) because their environment is predictable (the same plant on which the mother lives). However, when mothers make winged offspring, who must fly away into an unpredictable environment, they give them variable reproductive potential. I aim to demonstrate that this can only be considered within generation bet hedging, and can only be favoured by natural selection, if offspring with different reproductive potential also have different dispersal propensities and dispersal distances. In this way, a correlation between phenotype and environment is created that satisfies the assumption of bet hedging as an adaptive response to heterogeneity. A better understanding of bet hedging in aphids will provide us with clearer information on optimal tactics for living in a changing, and extremely variable, environment. This may guide tactics for pest control in a changing climate, and may even suggest optimal tactics for human resource use in the face of an unpredictable and resource-limited future.

所有的生物都生活在一个不确定的世界里，面对这种变化，它们必须让后代做好生存的准备。为了确保至少有一些后代能够存活下来繁殖，母亲们有几种策略可供选择。(i)悲观主义：母亲可能投入比通常所需更多的资源，以备时局艰难。（ii）可塑性：母亲可以为后代提供根据当时的环境条件改变表型的能力。（iii）风险对冲（或风险分散）：母亲可能产生具有多种表型的后代，希望至少其中一些能够存活下来繁殖。在后代在不同季节出现的生物体中，下注对冲的概念得到了大量支持：在这种情况下，非直觉的结果是，增加后代的可变性可以减少他们未来成功的差异，从而有利于适应性，并导致可遗传的下注对冲行为在种群中传播。这种迷人的解释也适用于那些后代在一个季节内经历不可预测的空间变化的生物。然而，这种代内下注对冲实际上很难发展。代间下注对冲之所以有效，是因为某种表型的后代都经历了相同的环境。代内下注套期保值只在非常小的种群中起作用，因为环境和表型之间没有相关性。蚜虫被认为是代内下注对冲的典型例子。当蚜虫母亲生产出没有翅膀的后代时，它们会给后代提供相同数量的子房（生殖投资），因为它们的环境是可预测的（与母亲生活在同一种植物上）。然而，当母亲生下长着翅膀的后代时，它们必须飞到一个不可预测的环境中，这就赋予了它们可变的生殖潜力。我的目的是证明，如果具有不同繁殖潜力的后代也具有不同的扩散倾向和扩散距离，这只能在代赌注对冲中考虑，并且只能在自然选择中得到青睐。通过这种方式，表型和环境之间的相关性被创造出来，满足了下注对冲作为对异质性的适应性反应的假设。更好地了解蚜虫的避险行为，将为我们提供更清晰的信息，让我们了解在一个不断变化、极其多变的环境中生存的最佳策略。这可以指导在气候变化中防治虫害的策略，甚至可以在面对不可预测和资源有限的未来时提出利用人力资源的最佳策略。

项目成果

Bottom-up effects of glucosinolate variation on aphid colony dynamics in wild cabbage populations

• DOI: 10.1111/j.1365-2311.2009.01111.x
• 发表时间: 2009-10-01
• 期刊: ECOLOGICAL ENTOMOLOGY
• 影响因子: 2.2
• 作者: Newton, Erika;Bullock, James M.;Hodgson, Dave
• 通讯作者: Hodgson, Dave