Collaborative Research: Demographic Heterogeneity within Populations and its Consequences

这项研究将使用模型来询问存活率和生育率的个体差异如何影响种群灭绝的风险。研究人员将研究导致人口比率变化的遗传和环境原因。他们将开发一种方法来模拟人口的增长，在这种方法中，个体的增长率以及出生和死亡率都不同。他们将利用大量关于植物种群中这些比率的研究，从已发表和未发表的关于这一主题的研究中汇编一个数据库。对数据的统计分析将得出关于人口率变化的普遍性的结论。这项研究很重要，因为人口学模型在保护、流行病学、野生动物管理、杂草和有害动物控制以及社会政策中被广泛使用。在考虑了性别、年龄或体型的差异后，这些模型几乎一致地对待种群中的个体，就好像他们都有相同的存活或生育机会。最近的研究表明，在估计种群增长率和灭绝风险时，这种种群内同质性的假设有时会导致重大错误。一个关键的目标是开发方法，帮助研究人员确定他们何时需要考虑人口统计学差异。

This study will use models to ask how individual variation in survival and reproductive rates affects population extinction risk. The investigators will examine both genetic and environmental causes of variation in demographic rates. They will develop a method for modeling growth of populations in which individuals vary in their growth rates and their birth and death rates. They will use the extensive body of research on these rates in plant populations, by compiling a database from published and unpublished research on this topic. Statistical analyses of the data will allow conclusions about the pervasiveness of variation in demographic rates.This research is important because models from demography are used widely in conservation, epidemiology, wildlife management, control of weeds and pest animals, and in social policy. Almost uniformly, these models treat individuals in a population - after accounting for differences due to sex, age, or size - as though they all have the same chances of surviving or giving birth. Recent research has shown that sometimes this assumption of homogeneity within populations can lead to substantial errors when estimating population growth rates and extinction risks. A key aim is to develop methods that help researchers determine when they need to account for demographic variation.