Combined and synergistic effects of landscape structure and population size fluctuation on genetic variation

尽管一个物种的个体相似，但他们很少是完全相同的。每个人在许多重要方面都有所不同。这些通过基因遗传的差异构成了遗传变异。遗传变异对物种和组成物种的种群的生存和进化至关重要。我们的实验室研究遗传变异以及如何在野生动物种群中保持这种变异。 我们对影响遗传变异的两个主要因素感兴趣。首先是人口规模。种群大小是种群中的个体数量，是决定遗传变异的最重要因素之一。较大的种群可以比较小的种群拥有更多的遗传变异。例如，由于一场严重的风暴，种群数量的下降可以消除大量的基因变异。第二个因素是周围景观的性质。地形通过决定来自其他地区的个体进入种群的难易程度来影响遗传变异，从而带来新的遗传变异。 许多研究人员研究了种群大小和地貌变化对遗传变异的单独影响。但是，对于这些过程是如何相互作用的，我们并没有很好的理解。例如，如果一个人口被不适宜居住的地形包围，人口数量下降的影响是否会更严重？目前，人类土地利用和气候变化同时改变着景观，使野生动物种群数量变得不稳定。如果我们想要防止这些环境变化的有害影响，我们需要更好地理解它们是如何结合在一起的。因此，我们实验室的目标是促进对种群大小和地形变化对野生动物遗传变异的综合影响的理解。 我们将研究落基山阿波罗蝴蝶的16个种群。20多年来，每年都会对这些种群的规模进行测量。在这段时间里，人口规模急剧下降，然后又两次回升。每年也从这些人群中收集用于遗传分析的样本。我们将使用这些样本和现代基因组学方法来测量不同年份种群的遗传变异。然后，我们将看看随着种群数量的变化，遗传变异是如何随着时间的推移而变化的。我们还将研究这些变化是如何受到周围景观特征的影响，这些景观特征阻碍或促进了个人在人群中的流动。 在寿命更长或在自然环境中占据更大区域的动物身上，这些过程要难得多。因此，我们的研究为理解种群大小和景观变化对其他动物遗传变异的综合影响提供了一个模型。我们的工作对保护野生动物很重要，因为它将提高对人类土地利用和气候变化如何相互作用影响野生动物的理解。

Although individuals of a species are similar, they are rarely identical. Individuals differ from each other in many important ways. Those differences that are inherited through genes constitute genetic variation. Genetic variation is critical for species, and the populations that make them up, to survive and evolve. Our lab studies genetic variation and how it is maintained in populations of wild animals. We are interested in two main factors that affect genetic variation. The first is population size. Population size is the number of individuals in a population, and is one of the most important things that determine genetic variation. Larger populations can hold more genetic variation than smaller ones. A drop in population size, because of a severe storm for example, can remove a lot of genetic variation. The second factor is the nature of the surrounding landscape. The landscape affects genetic variation by determining how easily individuals from other areas can move into a population, bringing new genetic variation with them. Many researchers have looked at the separate effects of changes in population size and landscape on genetic variation. But, we do not have a strong understanding of how these processes interact. For example, are the effects of a drop in population size more severe if a population is surrounded by inhospitable landscape? Currently, human land use and climate change are simultaneously altering landscapes and making wildlife populations less stable in size. If we want to prevent harmful effects of these environmental changes, we need a better understanding of how they act in combination. Our lab's goal is therefore to advance understanding of the combined effects of changes in population size and landscape on genetic variation in wild animals. We will study a group of 16 populations of the Rocky Mountain apollo butterfly. Sizes of these populations have been measured each year for over 20 years. Over this time, population sizes dropped dramatically, and then recovered, on two occasions. Samples for genetic analysis have also been collected from these populations yearly. We will use these samples, and modern genomic methods, to measure genetic variation of the populations in different years. We will then look at how genetic variation has changed over time with changes in population size. We will also examine how those changes were affected by characteristics of the surrounding landscape that either block or promote movement of individuals among the populations. These processes are much harder to track in animals that are longer lived or occupy larger areas on the landscape. Our research therefore provides a model for understanding combined effects of changes in population size and landscape on genetic variation in other animals. Our work is important for conservation because it will improve understanding of how human land use and climate change interact to affect wildlife.