Costs, consequences and context-dependency of intrafamilial conflict

家庭内部冲突的成本、后果和背景依赖性

基本信息

批准号：
NE/C002199/2
负责人：
Nicholas Royle
金额：
$ 10.54万
依托单位：
UNIVERSITY OF EXETER
依托单位国家：
英国
项目类别：
Fellowship
财政年份：
2007
资助国家：
英国
起止时间：
2007 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FC002199%2F2
关键词：
Costs consequences context dependency intrafamilial

项目摘要

The environment that an individual experiences during growth and development has profound implications for the future health and fitness of that individual during adulthood. In species that provide parental care offspring are usually reared together in broods, so close relations often provide the social environment in which growth and development takes place. However, because parental care is costly to parents (in time and energy), and availability of environmental resources essential for growth and development of young varies unpredictably, offspring demand for food and other resources often exceeds parental supply. As a consequence there may be conflicts of interest among family members over the supply of these parental resources (parental investment; PI), which affects the amount of resources available to individual offspring. The consequences of such conflicts within families can be pervasive, and have important effects for the diversity and evolution of life-history traits and behaviours such as growth rates, clutch size, sexual attractiveness and begging behaviour. The amount of resources available to individual offspring depends upon the amount of conflict, which is determined by the relatedness of family members and the availability of key resources in the environment. However, although the importance of within-family conflicts for growth, development and fitness is increasingly being recognised, very little is known about the mechanisms that underpin such conflicts, or the interrelationships between resource availability, conflict over these resources and the mechanisms that determine the costs and consequences of conflict. Previous work on zebra finches by the author showed that, although receiving less food, offspring reared under conditions of higher within-family conflict had faster growth compared to siblings reared under lower levels of conflict. As a result these offspring were less attractive as adults, indicating a substantial costs of rapid growth and of family conflict. These costs are most probably a consequence of increased oxidative stress, which occurs when high levels of free radicals, which are by-products of normal metabolic processes, cause damage to various cell components. Antioxidants provide protection against the damaging effects of free radicals. An important component of total antioxidant defence is provided by fat-soluble antioxidants, such as carotenoids and vitamin E, which are derived from the diet. The interaction between dietary availability of antioxidants and within-family conflicts has not previously been considered, but is likely to be important as variation in antioxidant availability determines the trade-off between self-maintenance and investment in growth and reproduction, and hence fitness. This project plans to use brood size manipulations, hand-rearing and parent removal experiments and cross-fostering to tease apart the effects of sexual conflict and sibling competition on growth and fitness of offspring, examine the cost basis of growth through the measurement of oxidative stress and manipulation of dietary antioxidant availability, and establish the behavioural mechanisms that underlie the allocation of PI in relation to the social and environmental context in which they are operating. The work integrates nutrition, reproductive ecophysiology and environmental uncertainty with behavioural ecology in examining the costs and consequences of variation in social and environmental effects early in life on adult health and fitness. If funded, the project would be conducted at the Institute of Biological and Life Sciences at the University of Glasgow, using zebra finches Taeniopygia guttata as a model species.

个人在成长和发展过程中经历的环境对其成年后的未来健康和健身具有深远的影响。在提供亲代照顾的物种中，后代通常在巢中一起抚养，因此密切的关系通常提供生长和发育的社会环境。然而，由于父母的照顾对父母来说是昂贵的（时间和精力），而且对幼崽生长和发育至关重要的环境资源的可用性变化不可预测，后代对食物和其他资源的需求往往超过父母的供应。因此，家庭成员之间可能会因父母资源（父母投资；PI）的供应而产生利益冲突，从而影响单个后代可获得的资源量。家庭内部此类冲突的后果可能是普遍存在的，并对生活史特征和行为（如生长速度、窝产数、性吸引力和乞讨行为）的多样性和进化产生重要影响。个体后代可用的资源量取决于冲突的程度，而冲突的程度则由家庭成员的相关性和环境中关键资源的可用性决定。然而，尽管人们越来越认识到家庭内部冲突对于成长、发展和健康的重要性，但人们对这种冲突背后的机制，或者资源可用性、对这些资源的冲突以及决定家庭内部冲突的机制之间的相互关系知之甚少。冲突的成本和后果。作者之前对斑胸草雀的研究表明，尽管获得的食物较少，但在家庭内部冲突较高的条件下抚养的后代与在较低程度的冲突下抚养的兄弟姐妹相比，生长速度更快。结果，这些后代成年后吸引力较低，这表明快速成长和家庭冲突付出了巨大代价。这些成本很可能是氧化应激增加的结果，当高水平的自由基（正常代谢过程的副产品）对各种细胞成分造成损害时，就会发生氧化应激。抗氧化剂可以防止自由基的破坏作用。总抗氧化防御的一个重要组成部分是由脂溶性抗氧化剂提供的，例如来自饮食的类胡萝卜素和维生素E。膳食中抗氧化剂的可用性与家庭内部冲突之间的相互作用以前没有被考虑过，但可能很重要，因为抗氧化剂可用性的变化决定了自我维持与生长和繁殖投资之间的权衡，从而决定了健康。该项目计划利用育雏规模控制、人工饲养和亲本去除实验以及交叉寄养来梳理性冲突和兄弟姐妹竞争对后代生长和健康的影响，通过测量氧化应激来检查生长的成本基础和操纵膳食抗氧化剂的可用性，并建立与他们所处的社会和环境背景相关的 PI 分配的行为机制。这项工作将营养、生殖生态生理学、环境不确定性与行为生态学相结合，研究生命早期社会和环境影响变化对成人健康和健身的成本和后果。如果获得资助，该项目将在格拉斯哥大学生物与生命科学研究所进行，使用斑胸草雀 Taeniopygia guttata 作为模式物种。