Understanding Age and Society using Natural Populations

点击翻译按钮获取中文摘要

A major issue facing almost all human societies around the globe is rapid ageing of the population. For example, over the past 40years alone, the average age in the UK has increased from 34 to over-40, and, in the next 30 years, the amount of over-65 year olds is predicted to double from today's number and reach ~20million individuals. As age affects almost all aspects of life, including behaviour, health, and reproduction, these changes in age composition are expected to have enormous consequences for society. But, as this is the first time in history that human populations have ever experienced 'ageing' in this way, it is exceptionally difficult to make predictions regarding these changes. Interestingly, ageing is now known to not only occur in humans, but also across the animal kingdom. A broad range of studies have found evidence of ageing in hundreds of species, ranging from insects to whales. In fact, natural animal populations have become widely accepted as particularly useful for understanding how individuals age, and the mechanisms that underpin how individuals change as they grow older. In this proposal, I demonstrate that natural populations also have great, but previously unrecognized, potential for understanding how societies age, particularly due to the following three complementary reasons: Firstly, unlike the human population (which has never 'aged' before), many animal societies have shown large variation in their population age compositions whilst being monitored. Therefore, this will allow me to develop an understanding of ageing societies based on previous patterns of ageing within the population (instead of relying entirely on predictions into the future). Secondly, recent advances in animal tracking technologies have given rise to hundreds of studies that quantify wild animal social networks in great detail, often over individuals' entire lifetimes and across multiple generations. I propose that such fine-scale datasets will allow the examination of fundamental processes governing how individuals' social behaviour changes as they age, and how this structures societies over time. Finally, experiments are often key to separating 'correlation from causation' across all fields, and this is particularly important in research surrounding sociality (as the behaviour of one individual automatically affects the behaviour of those it interacts with). My previous research has developed a novel method for experimentally manipulating a wild bird social system. I will use this unique approach to determine how individual age directly effects society structure and social processes (such as the development and spread of new information and cooperative behaviour). Therefore, through amassing and analyzing various species' and populations' social networks over time and across various age compositions, along with carrying out social experiments within a model study system, I will take full advantage of the unrecognized opportunities that natural populations offer in terms of gaining novel insights into the interplay between age and society. This research will provide a new understanding of how age shapes individuals' social behaviour and emerging society structure, the ecological and evolutionary forces affecting this effect, and the consequences of age for the fundamental social processes of information transmission and cooperation.