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)提供资金的。地球的生态系统？S生态系统北极对气候变化最敏感。最近北极环境变化速度的加快对驯鹿等在文化和经济上具有重要意义的适应北极的物种的生存构成了相当大的挑战。能够将外部过程(如北极栖息地的气候或人为变化)和内在过程(如依赖密度的资源限制)在种群动态中的作用分开，将为北极生物群的保护和管理提供关键的见解。然而，到目前为止，由于缺乏自然人口的长期数据，这种努力受到了阻碍。在这里，现代进化论和生态学的方法首次结合在一起，产生了一种幸存的和两种灭绝的北极哺乳动物：草原野牛、马和驯鹿的种群动态的长期重建。为了实现这一目标，将产生迄今为止规模最大、采样密度最高的古代DNA数据集，重点放在两个环境截然不同的北极地区，它们具有特殊的年代学控制和至少25万年前的详细古环境记录。这些数据将为直接评估环境变化对北极动物长期动态和灭绝风险的作用提供第一次机会。将生成一个几乎连续的时间序列，详细说明野牛、马和驯鹿种群的规模和结构的变化，跨越一个完整的冰川/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)显著扩大古起源重建的时间范围；(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，还将利用高通量测序技术和新的实验方法，对线粒体DNA序列中的进化信息进行详细分析，以开发第一个共域(空间和时间)物种的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缓解当代气候变化对现有北极物种的不利后果的能力。

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.