Physiological mediation of vertebrate invasions

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。入侵物种对生态系统功能、生物多样性乃至人类健康构成了巨大且日益严重的威胁。然而，使一些物种扩大其活动范围并成为害虫的特征仍未得到充分研究。该项目的重点是确定世界如何？世界上最常见的鸣禽，麻雀，已经能够在地球的大部分地区定居。原产于欧亚大陆，现在在除南极洲以外的所有大陆都有发现。一些入侵仍在进行中，比如大约50年前在肯尼亚开始的入侵。该物种被引入沿海城市蒙巴萨，向西向乌干达扩散，主要进入人类居住的地区。据推测，这种范围的扩大是通过生理特征的调整来促进的，即牺牲昂贵的免疫防御。新兴的生态免疫学领域揭示了与直觉相反的是，动物并不总是拥有最高水平的免疫防御；在某些情况下，比如在入侵期间，它们似乎会牺牲特别昂贵的成分，将资源分配给更直接有利可图的活动，比如繁殖。为了验证入侵是通过牺牲免疫防御来促进的假设，将在肯尼亚各地进行为期数年的比较实地和实验室研究。这种跨学科的方法将在“野生”环境中使用现代技术，并将为如何控制动物入侵提供新的见解。这项工作的影响将是广泛的，涉及美国学生和科学家、肯尼亚国家博物馆的工作人员以及肯尼亚本土学生和他们的老师的共同努力。总而言之，这项工作将为进化生物学的一个未被充分探索的领域提供新的信息，提高我们预防入侵的能力，同时加强世界上这种网络尚不多见的部分地区的科学关系。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Invasive species are a large and growing threat to ecosystem function, biodiversity and even human health. However, the traits that enable some species to expand their ranges and become pests remain understudied. The focus of the project is to ascertain how the world?s most common songbird, the house sparrow, has been able to colonize most of the planet. Native to Eurasia, this species now is found on all continents but Antarctica. Some invasions are still ongoing, such as the one in Kenya that began about 50 years ago. Introduced to the coastal city of Mombasa, the species is spreading westward towards Uganda predominantly into areas occupied by humans. It is hypothesized that this range expansion is being facilitated by adjustments in physiological traits, namely sacrifices of expensive immune defenses. The emerging field of ecological immunology is revealing that contrary to intuition, animals do not always possess maximal levels of immune defense; in some contexts, such as during invasions, they appear to sacrifice particularly costly components to allocate resources to more immediately lucrative activities, such as reproduction. To test the hypothesis that invasions are fostered by sacrifices of immune defenses, comparative field and lab studies across Kenya will be conducted over several years. This interdisciplinary approach will involve modern technologies in a 'wild' setting, and will provide new insight into how to control animal invasions. The impacts of the work will be broad involving the joint efforts of American students and scientists, staff at the National Museum of Kenya, and native Kenyan schoolchildren and their teachers. In sum, the work will provide new information for an underexplored area of evolutionary biology, improve our ability to preempt invasions, and simultaneously reinforce scientific relationships in parts of the world where such networks are yet rare.