Collaborative Research: The dynamics of geographic ranges: Origin and maintenance of marine diversity gradients

合作研究：地理范围的动态：海洋多样性梯度的起源和维持。瓦伦丁，加州大学伯克利分校这个奖项是根据2009年美国复苏和再投资法案（公法111-5）资助。 生物多样性中最引人注目的大规模模式是从两极到热带的物种和高级分类群的数量急剧增加。然而，产生和维持这一趋势的动力仍然知之甚少，尽管它们不仅对进化和生态理论很重要，而且对生物资源的管理和保护也很重要。在开发海洋双壳类作为跟踪生物多样性进化和地理历史的模型系统时（因为双壳类在大多数海洋环境中具有多样性和良好的采样，并且具有丰富和有据可查的化石记录），我们发现进化谱系在纬度上的空间扩展是塑造全球多样性梯度的关键因素。我们拟议的研究将使用海洋双壳类来评估这些动态是如何运作的，通过追溯当今的双壳类生物多样性，追溯到过去的2500万年。我们将集中讨论三个主要问题：1）范围扩展的过程是什么？2)范围扩张是有选择性的吗？ 3)是什么阻碍了范围的扩大？这项工作阐明了化石记录有助于理解全球和区域范围内生物多样性动态的关键数据和分析。 我们可以利用地质记录来评估支配这些动态的主要生物因素，以及内在的生物因素与外在的、随时间变化的气候因素在塑造时空多样性方面的相互作用。通过记录海洋双壳类对最近地质历史气候事件的长期反应，我们的研究也将为预测活生物群对未来气候变化的反应提供更好的基础。此外，通过将生物因素，如身体大小和地理范围大小纳入动态框架，这项工作将在古生物学数据和当今生物多样性研究之间架起一座桥梁。这项研究将支持一名研究生和一名博士后研究人员的教育，他们将被视为这项工作的全面合作者，包括研究规划、成果展示、出版和职业指导方面的培训。我们将继续开发从我们的研究中获得的在线教育资源（在理解进化网站上关于我们工作的页面已收到58，000次访问）。

Collaborative Research: The dynamics of geographic ranges: Origin and maintenance of marine diversity gradientsDavid I Jablonski, University of ChicagoJames W. Valentine, University of California, BerkeleyThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The most striking large-scale pattern in biological diversity is the dramatic increase in the number of species and higher taxa from the poles to the tropics. However, the dynamics that generate and maintain that trend remain poorly understood, despite their importance not only for evolutionary and ecological theory, but for the management and conservation of biological resources. In developing marine bivalves as a model system for tracking evolutionary and geographic histories of biodiversity (because bivalves are diverse and well-sampled in most marine environments and have a rich and well-documented fossil record), we have found that the spatial expansion of evolutionary lineages across latitude is a crucial factor shaping the global diversity gradient. Our proposed study will use the marine bivalves to evaluate how these dynamics operate, by tracing present-day bivalve biodiversity back through the past 25 million years. We will focus on three major questions: 1) What is the process of range expansion?2) Is range expansion selective? 3) What inhibits range expansion? This work exemplifies the key data and analyses that the fossil record can contribute to understanding biodiversity dynamics at global and regional scales. We can use the geologic record to assess both the major biological factors governing those dynamics, and the interaction of intrinsic, biological factors with extrinsic, time-varying climatic factors in shaping diversity in time and space. By documenting the long-term responses of marine bivalves to climatic events of the recent geologic past, our study will also provide a better foundation for predicting the response of the living biota to future climate change. In addition, by incorporating biotic factors such as body size and geographic range size in a dynamical framework, this work will furnish a bridge between paleontological data and studies of present-day biodiversity. And this research will support the education of a graduate student and a postdoctoral researcher, who will be treated as full collaborators in this work, including training in research planning, presentation of results, publication, and career guidance. We will continue to develop on-line educational resources derived from our research (pages on our work at the Understanding Evolution website have received 58,000 visits).