Quantitative genetics of behaviour: cooperative breeding and lifetime fitness

为什么有些人比其他人更乐于助人？为什么有些人会在父母身边安顿下来，而另一些人则会离开呢？起初，这些似乎是极其复杂的问题，因为我们不知道行为是文化遗传还是遗传遗传，也不知道表达行为的背景是否重要。我们从父母那里继承了我们的基因，他们也从父母那里继承了基因。通过构建家谱并观察家庭成员的行为如何比无关个体的行为更相似，我们可以发现这些行为的遗传贡献。然后，我们可以看看这些行为的好处，并开始理解为什么这些行为会以它们所具有的方式演变。考虑我们表达行为的情境或环境也是非常重要的。我们可能会在阳光明媚的日子停下来帮助迷路的人，但不会在倾盆大雨时停下来帮助他们；同样，我们周围的人可能会影响我们的决定。情况或环境显然有能力影响我们的行为。如果我们的行为影响我们的生存或繁殖成功(例如，我们在下雨时帮助别人得了肺炎)，并且这种行为(帮助的倾向)是遗传的，那么环境就有能力影响哪些行为进化。进化是选择的结果；选择是导致成功行为生存的过程。个体会在所经历的条件下进化出最大限度地取得成功的行为；然而，我们与之互动的环境或个人在时间和空间上不断变化或变化，个人必须拥有一系列灵活的行为才能做出反应。因此，环境或社会因素会影响我们行为演变的方式。重要的是要研究环境和社会变化如何影响自然人口的行为，以便我们了解行为是如何演变的，以及是什么保持了所发生的行为策略的多样性。我将利用最近的分析发展来探索哪些行为是遗传的，以及表达行为的环境和背景如何影响这一点。我将在两个自然鸟类种群中进行研究，这两个种群代表了鸟类合作繁育者最详细的长期遗传数据集。许多鱼类、昆虫、鸟类和哺乳动物(如猫鼬庄园)都存在合作繁殖。我将调查个体在合作繁殖行为上是否存在差异，以及这些差异是否可遗传；例如，我将量化帮助倾向的差异在多大程度上是遗传的。然后，我将研究环境和社会互动是如何影响行为的。我的两个研究物种在领地上以家庭群体的形式生活。有些地区比另一些地区更好，有些年份的天气比其他年份更好，而且有些地区有不同的个体。我会问，这种环境和社会差异如何影响行为的表达。通过探索环境和社会环境如何影响这些野生合作繁殖系统的进化动态，我将深入了解在其他合作物种(如人类)中可能类似的行为的遗传基础。这将提高我们对个体适应环境变异性和变化的程度的理解，在这个人类活动加速变化的时代，这对保护受关注的物种(例如我研究的一个物种)至关重要。最后，我将评估我们对社会行为演变的理解所基于的基础。为此，我将开发理论模型，使用来自封闭人群的精确健康估计来调查健康衡量标准的表现。这将对合作育种和一般的进化生物学研究具有广泛的相关性。

Why are some individuals more helpful than others? Why do some individuals settle close to their parents when others disperse? At first these appear to be extremely complex questions, given that we don't know whether behaviour is culturally or genetically inherited, or whether the context in which it is expressed matters. We inherit our genes from our parents and they inherit them from their parents. By building a family tree and looking at how the behaviours of family members are more similar than behaviours of unrelated individuals, we can discover the inherited contribution to these behaviours. We can then look at the benefits of these behaviours, and begin to understand why these behaviours have evolved in the way that they have. It is also very important to consider the situation or environment in which we express behaviour. We might stop to help someone who is lost on a sunny day, but not when it's pouring with rain; equally the people around us may influence our decision. Situations or environments clearly have the ability to influence our behaviour. If our behaviour influences our survival or breeding success (e.g. we get pneumonia helping someone when it's raining), and this behaviour (tendency to help) is inherited, then the environment has the ability to influence which behaviours evolve. Evolution is the result of selection; selection is the process that leads to the survival of successful behaviours. Individuals evolve behaviour that maximises their success in the conditions they experience; however, the environment or individuals that we interact with are constantly varying or changing, over time and space, and individuals must have a range of flexible behaviours to allow them to respond. Environmental or social factors can therefore influence the way in which our behaviour evolves. It is important to study how environmental and social variation influences behaviours in natural populations so that we understand how behaviour evolves and what maintains the diversity of behavioural strategies that occur. I will use recent analytical developments to explore which behaviours are inherited and how the environment and context in which behaviours are expressed influences this. I will investigate this in two natural populations of birds that represent the most detailed long-term genetic data sets of avian cooperative breeders. Cooperative breeding occurs in many fish, insects, birds and mammals (e.g. Meerkat Manor). I will investigate whether individuals differ in their cooperative-breeding behaviour and whether these differences are heritable; for example, I will quantify how much of the variation in tendency to help is genetic. I will then examine how the environment and social interactions influence behaviours. My two study species live in family groups on territories. Some territories are better than others, the weather is better in some years than others, and territories contain different individuals. I will ask how this environmental and social variation affects the expression of behaviours. By exploring how the environment and social surroundings influence evolutionary dynamics in these wild cooperative-breeding systems, I will gain insights into the genetic basis of behaviours that are likely to be similar in other cooperative species such as humans. This will improve our understanding of the degree to which individuals can adapt to environmental variability and change, crucial to species of conservation concern (e.g. one of my study species) in these times of accelerated anthropogenic change. Finally, I will assess the foundations on which our understanding of the evolution of social behaviour is based. I will do this by developing theoretical models, using precise fitness estimates from a closed population, to investigate the performance of fitness measures. This will have widespread relevance to cooperative breeding and evolutionary biology studies in general.