Collaborative Research: How Do Social and Habitat Complexities Shape Brain Structure?

卡罗利·A·沙姆韦1，汉斯·A·霍夫曼21新英格兰水族馆；2哈佛大学合作研究：社会和生境的复杂性如何塑造大脑结构？人类的大脑比任何其他灵长类物种的大脑都大。随着人类的进化，是什么环境或社会力量导致了我们自己的大脑扩张？如果一只动物生活在一个大家庭群体中，与更孤独的物种相比，识别群体中个别成员的需要是否会带来更好的面孔识别能力？由于大多数脊椎动物群体只提供有限数量的物种进行比较，这些问题将在物种丰富的非洲慈鱼身上进行研究，这些鱼类生活在不同的栖息地，表现出惊人的社会行为范围。主要研究人员发现，在复杂的岩石环境中，复杂的行为比在简单的沙地生境中更容易发生。由于每个湖泊中有大量密切相关但行为各异的物种(这使得慈鱼成为比较研究探索大脑和行为如何进化的“黄金标准”)，在比较研究中，一个因素(例如，社会行为)可以保持不变，而另一个因素(例如，栖息地)可以变化。通过这种方式，可以证明环境和社会这两个因素都是重要的进化力量。在目前的研究中，将比较不同社会行为或栖息地的物种的大脑结构和认知能力(如个人识别和空间记忆)。最终，这项工作将阐明环境和社会因素，如一夫一妻制和家庭群体如何塑造大脑结构和功能。正在研究的复杂行为，如空间记忆和识别，与人类直接相关。

Caroly A. Shumway1, Hans A. Hofmann21New England Aquarium; 2Harvard UniversityCollaborative Research: How Do Social and Habitat Complexities Shape Brain Structure?The human brain is larger than that of any other primate species. As humans evolved, what environmental or social forces caused our own brain expansion? If an animal lives in an extended family group, does the need to identify individual members within the group lead to a better ability to recognize faces, compared with species that are more solitary? Since most vertebrate groups offer only a limited number of species for comparison, these questions will be studied in the species-rich African cichlid fishes that live in diverse habitats and show an astonishing range of social behaviors. The principal investigators have found that complex behaviors occur more often in complex rock environments than in simpler sand habitats. Because of the large numbers of closely related but behaviorally diverse species in each lake (which makes cichlids the "gold standard" for comparative studies exploring how brain and behavior evolved), one factor (e.g., social behavior) can be kept constant in a comparative study while varying the other (e.g., habitat). In this way it has been possible to show that both factors - environment and social - are important evolutionary forces. In the present study brain structures and cognitive abilities (such as individual recognition and spatial memory) of species differing in social behavior or habitat will be compared. Ultimately, this work will shed light on how environmental and social factors like monogamy and familial groups shape brain structure and function. The complex behaviors being studied, such as spatial memory and recognition, are of direct relevance to humans.