North american biodiversity: testing the effects of phylogeny and biogeography in late cretaceous and cenozoic mammals

北美生物多样性：测试白垩纪晚期和新生代哺乳动物的系统发育和生物地理学的影响

• 批准号: 331286-2011
• 负责人: Theodor, Jessica
• 金额: $ 1.89万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=572169
• 关键词: North; american; biodiversity; testing; effects

Understanding which factors affect species diversity in different environments is critical to our ability to predict the consequences of climatic changes. By looking at past periods of time we can begin to understand the long-term consequences of changes that we can otherwise only observe over very brief time scales. A number of factors can affect species diversity, including features that different groups inherit from their ancestors. In order to understand ancestral features, we need a well-resolved family tree. I am interested in the radiation of the group of terrestrial mammals that gave rise to whales. New data show that whales are descended from one group of ungulates, the artiodactyls (cows, pigs, camels and hippos), but we don't fully understand the details of the relationships of whales to their extinct ancestors. This research will clarify these relationships and allow study of diversity patterns over the 54 million year history of this group. Other external factors, such as how species are distributed across continents, and how they change over time, can also tell us a great deal about how those species may respond to major changes. This proposal will address how mammalian species diversity and distribution across North America changed over the time period from the age of dinosaurs, 70 million years ago, through the major climatic changes following the asteroid impact 65 million years ago, rapid global warming 56 million years ago, and slower cooling beginning about 34 million years ago. There is some evidence over this time period that some fossils found in western Canada are endemic and are not known from further south, and this proposal will test whether these differences are well supported and whether we should consider western Canada to belong to a separate bioregion that responded differently to change.

了解哪些因素会影响不同环境中的物种多样性，对于我们预测气候变化后果的能力至关重要。通过观察过去的时间段，我们可以开始理解变化的长期后果，否则我们只能在非常短的时间尺度上观察。 许多因素会影响物种多样性，包括不同群体从祖先那里继承的特征。为了了解祖先的特征，我们需要一个清晰的家谱。我感兴趣的是陆地哺乳动物群的辐射，这些哺乳动物是鲸鱼的起源。新的数据表明，鲸鱼是有蹄类动物的后裔，偶蹄类（牛，猪，骆驼和河马），但我们并不完全了解鲸鱼与其灭绝祖先关系的细节。这项研究将澄清这些关系，并允许研究这个群体5400万年历史上的多样性模式。 其他外部因素，如物种如何在大陆上分布，以及它们如何随时间变化，也可以告诉我们这些物种如何应对重大变化。该提案将讨论从7000万年前的恐龙时代到6500万年前小行星撞击后的主要气候变化，5600万年前全球迅速变暖以及大约3400万年前开始的缓慢冷却，整个北美的哺乳动物物种多样性和分布是如何变化的。在这段时间里，有一些证据表明，在加拿大西部发现的一些化石是地方性的，在更南部的地方是不知道的，这个提议将测试这些差异是否得到很好的支持，以及我们是否应该认为加拿大西部属于一个单独的生物区，对变化的反应不同。