Culture and society in matrilineal whales

文化是人类的标志性特征。然而，文化被定义为从其他个体学习并在社区内共享的行为，也是非人类生物学的一部分。与基因从父母到后代的遗传相比，文化以多种方式传播，例如从同伴到同伴或从老师到学生。这样的对比意味着，具有重要文化背景的物种与那些基因在信息传递中占绝对主导地位的物种相比，其行为可能截然不同。关于动物文化的一些最有力的证据来自鲸鱼和海豚，而一些最令人信服的结果来自我对抹香鲸的长期研究项目。了解文化在鲸鱼中的作用是我研究的长期目标。

Culture is the signature characteristic of humans. However culture, defined as behaviour that is learned from other individuals and shared within a community, is also a part of the biology of non-humans. Compared with the parent-to-offspring inheritance of genes, culture moves in a diversity of ways, for instance from peer to peer or teacher to pupil. Such contrasts mean that species with important cultures may behave quite differently compared with those for which genes overwhelmingly dominate the transmission of information from one individual to another. Some of the strongest evidence for animal culture is among the whales and dolphins, and some of the most compelling results come from my long-term research programme on sperm whales. Understanding the role of culture among whales is the long-term goal of my research. We have field studies of sperm whales in both the eastern Pacific and North Atlantic. Female and young sperm whales live and move in family social units. In the Pacific we have found that each social unit is a member of a clan. Clans, each containing thousands of animals, differ in their vocal dialects, movements, success in foraging and birth rates. However, two clans may use the same area, and they are not genetically distinct. This implies that the differences between the clans are cultural, and makes the clans an ideal system within which to assess the significance of culture in animals. In the next phase of my research we will use suction-cup tags that stay on the whales for periods of hours, recording vocalizations and movements, to see whether there are consistent fine-scale differences between the ways animals from the different clans move and respond to their environment, as there are between human ethnic groups. We will also measure hormonal levels of animals in different clans to test whether culture affects physiology in sperm whales, again as it does with humans. Symbolic marking, in which cultural symbols mark social groups, so increasing the distinctions between the groups, is sometimes considered to be the hallmark of human culture. We will record the behaviour and vocalizations of social units as we broadcast the vocalizations of sperm whales from different units, clans and geographic areas in order to test the hypothesis that the codas are used as symbolic markers of clan membership. In the eastern Caribbean, off the island of Dominica, we have a more closely-focussed study where individual whales and their social units, with about nine animals in each, are known in detail. Here the focus will be on cultural differences at the level of the social unit, as well as the role and personality of individuals. Off Nova Scotia, we study a second matrilineal whale species, the long-finned pilot whale. As this project develops, we will first examine the extent to which their social system is based upon kinship. We will then look for cultural behaviour that is characteristic of different social units, especially vocalizations. To add value to studies of social structure, I plan to develop a new approach for characterizing animal social networks. It will give a direct measure of affiliation between pairs of individuals, after accounting for other factors that affect the rates at which they associate, factors such as range overlap and kinship. My research programme adds a key component, an additional cultural dimension, as we try both to understand the whales themselves as individuals with cultures and roles in society, as well as to conserve their populations. Moreover, when considering the extraordinary evolution of human culture, my studies of whales provide an unusual but potent context, that of the parallel evolution of complex cultures in a very different environment.