Collaborative research: Understanding the role of environmental change on the long-term population dynamics of one surviving and two extinct arctic mammals

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。地球的？北极的生态系统对气候变化最为敏感。最近北极地区环境变化速度的加快对具有重要文化和经济意义的适应北极的物种（如驯鹿）的生存构成了相当大的挑战。理清外部过程（如气候或人为变化对北极栖息地的影响）和内部过程（如密度依赖的资源限制）在种群动态中的作用的能力，将为北极生物群的保护和管理提供关键见解。然而，由于缺乏自然种群的长期数据，这种努力迄今受到阻碍。在这里，当代进化和生态方法首次被整合在一起，产生了一种生存和两种灭绝的北极哺乳动物的种群动态的长期重建：草原野牛、马和驯鹿。为了实现这一目标，迄今为止最大、最密集采样的古代DNA数据集将被制作出来，重点放在两个环境截然不同的北极地区，它们具有特殊的时间控制和详细的古环境记录，可以追溯到至少25万年前。这些数据将为直接评估环境变化对北极动物群长期动态和灭绝风险的作用提供第一次机会。将生成一个近连续的时间序列，详细描述野牛、马和驯鹿种群的大小和结构变化，跨越一个完整的冰期/间冰期循环和几个主要的环境变化时期。新的分析技术将被开发：(a)显著扩展古成因重建的时间范围；(b)将地理和生态数据明确纳入人口分析；(c)检测和量化内在和外在过程在大型食草动物自然种群命运中的作用。此外，将对线粒体DNA序列的进化信息进行详细分析，使用高通量测序技术和新颖的实验方法，为同域（空间和时间）物种开发第一个完整线粒体基因组的比较时间数据集。此外，了解物种如何应对以前的气候变化可能会提高我们预测和减轻当代气候变化对现存北极物种的不利影响的能力。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Of the planet?s ecosystems the Arctic is the most sensitive to climate change. Recent increases in the rate of environmental change in the Arctic pose considerable challenges to the survival of culturally and economically important, arctic-adapted species such as caribou. An ability to disentangle the roles of extrinsic processes, such as climatic or anthropogenic changes to the arctic habitat, and intrinsic processes, such as density-dependent resource limitation, in the dynamics of populations would provide key insights for conservation and management of the arctic biota. However, such efforts have thus far been hindered by the scarcity of long-term data for natural populations. Here, contemporary evolutionary and ecological approaches are integrated for the first time to produce long-term reconstructions of the population dynamics of one surviving and two extinct and arctic mammals: steppe bison, horses, and caribou. To achieve this, the largest, most densely sampled ancient DNA data sets to date will be produced, focusing on two environmentally distinct arctic localities with exceptional chronological control and detailed paleoenvironmental records going back at least 250,000 years. These data will provide the first opportunity to directly evaluate the role of environmental change on the long-term dynamics and extinction risk of arctic fauna. A near-continuous time series detailing changes in the size and structure of bison, horse and caribou populations will be generated, spanning one complete glacial/interglacial cycle and several periods of major environmental change. Novel analytical techniques will be developed to (a) significantly extend the temporal range of paleogenetic reconstructions; (b) incorporate geographic and ecological data explicitly into demographic analyses; and (c) detect and quantify the role of intrinsic and extrinsic processes in the fate of natural populations of large herbivores. In addition, a detailed analysis of evolutionary information in mitochondrial DNA sequences will be performed, using high-throughput sequencing technology and novel experimental methodology to develop the first comparative temporal data set of complete mitochondrial genomes for sympatric (spatially and temporally) species. In addition, understanding how species respond to previous periods of climate change may improve our ability to forecast and mitigate adverse consequences of contemporary climate change for extant arctic species.