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。最近北极环境变化速度加快，对驯鹿等在文化和经济上具有重要意义、适应北极的物种的生存构成了相当大的挑战。能够理清外在过程的作用，如气候或人为变化的北极栖息地，和内在过程，如密度依赖资源限制，在人口动态将提供关键的见解北极生物群的保护和管理。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，当代进化和生态学的方法是第一次整合，以产生长期重建的种群动态的一个幸存者和两个灭绝和北极哺乳动物：草原野牛，马，驯鹿。为了实现这一目标，将产生迄今为止最大、采样最密集的古代DNA数据集，重点关注两个环境不同的北极地区，这些地区具有特殊的年代控制和详细的古环境记录，至少可以追溯到25万年前。这些数据将首次提供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的机会。将产生一个几乎连续的时间序列，详细说明野牛、马和驯鹿种群的大小和结构的变化，跨越一个完整的冰期/间冰期周期和几个重大环境变化时期。将开发新的分析技术，以（a）显着延长的时间范围的古发生重建;（B）将地理和生态数据明确纳入人口分析;（c）检测和量化的作用，内在和外在的过程中的命运的自然种群的大型食草动物。此外，将进行线粒体DNA序列进化信息的详细分析，使用高通量测序技术和新的实验方法，以开发同域（空间和时间）物种的完整线粒体基因组的第一个比较时间数据集。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.