Collaborative Research: Origins and drivers of extinction of Caribbean avifauna

合作研究：加勒比鸟类灭绝的起源和驱动因素

• 批准号: 2034316
• 负责人: Jonathan Baker
• 金额: $ 41.64万
• 依托单位: Board of Regents, NSHE, obo University of Nevada, Reno
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-02-01 至 2025-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2034316&HistoricalAwards=false
• 关键词: Collaborative; Research; Origins; drivers; extinction

Current vertebrate diversity has been dramatically shaped by an ongoing mass extinction event that began after the last ice age ended, approximately 18,000 years ago. The timing of at least some of these extinctions often coincides with human arrival into newly colonized areas. While extinctions since the last ice age have occurred worldwide, the islands that make up the Caribbean have been perhaps the single hardest hit region. This island system, rich in well-preserved paleontological and archaeological sites, has preserved a spectacular record of both past bird diversity and human occupation. Still, our knowledge of the patterns, causes, and consequences of long-term changes to Caribbean bird communities remains surprisingly limited. This knowledge gap hampers our understanding of past diversity changes and its causes, and thus our ability to manage and conserve remaining diversity into the future. This research focuses on closing these knowledge gaps using DNA from fossils (ancient DNA) to understand taxonomic affinities of extinct species, and radiocarbon dating to determine the last occurrence of a species. This approach provides critical information to determine who these species were, and to time their losses in relation to climate change and waves of human arrivals to the islands. This project also focuses on the characteristics of species that have made them more vulnerable to extinction (for example, flightlessness) as a means to more completely understand the causes of extinction in the past and forecast the extinction risk for existing species. This project has broad societal impact through its educational and outreach components. The project will provide training for underrepresented students in science, focusing on extinction and ancient DNA, and develop classroom content for K-12 classes in Florida in partnership with the University of Florida Thomson Earth Science Institute’s (TESI) Scientist in Every Florida School (SEFS) program. And to further public understanding of science, and to bolster conservation efforts for threatened Caribbean birds, the researchers will develop a documentary video in both English and Spanish and work with museum-based outreach efforts to inform wide audiences across the Caribbean islands.It is estimated that 12% of the bird species in the Caribbean either went extinct or were extirpated since the late Pleistocene, with many more now considered to be endangered or threatened. Less well understood is the role humans have played in these extinctions and population losses. Because human arrival to these islands occurred much later than on the mainland, archeological and paleontological evidence can be used to determine how humans interacted with the local fauna upon their arrival to domesticate, translocate, and cause the extinction of some species. Evidence of this lost avian diversity is fragmentary, often represented by only a few specimens with limited morphological characters. This causes challenges for proper phylogenetic placement, especially given potential for convergence due to shared life histories such as flightlessness. In this project researchers will build phylogenetic trees of clades of birds including modern, extinct and extirpated taxa to determine the phylogenetic and trait affinities of these species. This work will also elucidate biogeographic patterns of the full endemic fauna of the Caribbean, that has been obscured due to extinctions of enigmatic taxa, and build a picture of the level of biodiversity loss in terms of phylogenetic and trait diversity. A key next step is to then integrate new phylogenetic knowledge into a larger context of overall avian diversity patterns to explicitly quantify past loss of phylogenetic diversity across the Caribbean. We will generate a new metric, diversity loss risk, that integrates insight from phylogenetics, traits, and past extinction events to reveal which extant species are of greatest concern for preventing permanent phylogenetic diversity loss.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

目前脊椎动物的多样性已经被一场持续不断的大灭绝事件戏剧性地塑造了出来，这场大灭绝事件始于大约1.8万年前的上一个冰河时代结束后。至少其中一些物种灭绝的时间往往与人类到达新殖民地区的时间一致。虽然自上一个冰河时代以来，物种灭绝在全球范围内发生，但构成加勒比地区的岛屿可能是受打击最严重的地区。这个岛屿系统拥有丰富的保存完好的古生物和考古遗址，保存了过去鸟类多样性和人类活动的壮观记录。尽管如此，我们对加勒比海鸟类群落长期变化的模式、原因和后果的了解仍然非常有限。这种知识差距阻碍了我们对过去多样性变化及其原因的理解，从而阻碍了我们管理和保护未来剩余多样性的能力。本研究的重点是利用化石DNA（古代DNA）来了解灭绝物种的分类亲缘关系，并利用放射性碳定年法来确定物种的最后出现时间，从而弥合这些知识空白。这种方法提供了关键信息，可以确定这些物种是谁，并根据气候变化和人类到达岛屿的浪潮来确定它们的损失时间。该项目还将重点关注使其更容易灭绝的物种的特征（例如，不会飞行），以更全面地了解过去灭绝的原因，并预测现有物种的灭绝风险。该项目通过其教育和外联部分具有广泛的社会影响。该项目将为代表性不足的学生提供科学培训，重点关注灭绝和古代DNA，并与佛罗里达大学汤姆森地球科学研究所（TESI）的“佛罗里达每所学校的科学家”（SEFS）项目合作，为佛罗里达州的K-12班开发课堂内容。为了进一步加深公众对科学的理解，并加强对受威胁的加勒比鸟类的保护工作，研究人员将制作一部英语和西班牙语的纪录片，并与以博物馆为基础的推广工作合作，向加勒比岛屿上的广大观众提供信息。据估计，自更新世晚期以来，加勒比地区有12%的鸟类已经灭绝或灭绝，现在有更多的鸟类被认为濒临灭绝或受到威胁。人们对人类在这些物种灭绝和人口减少中所扮演的角色知之甚少。由于人类到达这些岛屿的时间比大陆晚得多，考古学和古生物学的证据可以用来确定人类在到达时是如何与当地动物相互作用的，从而驯化、迁移和导致一些物种的灭绝。这种鸟类多样性丧失的证据是零碎的，通常只有少数具有有限形态特征的标本。这给正确的系统发育定位带来了挑战，特别是考虑到由于共同的生活史（如不会飞行）而有可能趋同。在这个项目中，研究人员将建立鸟类进化枝的系统发育树，包括现代、灭绝和灭绝的分类群，以确定这些物种的系统发育和性状亲和力。这项工作还将阐明加勒比地区全部特有动物群的生物地理格局，这些格局由于神秘的分类群的灭绝而变得模糊不清，并从系统发育和性状多样性的角度建立生物多样性丧失程度的图景。关键的下一步是将新的系统发育知识整合到整体鸟类多样性模式的更大背景中，以明确量化整个加勒比地区过去系统发育多样性的丧失。我们将生成一个新的度量，即多样性丧失风险，该度量综合了系统发育、特征和过去灭绝事件的见解，以揭示哪些现存物种最值得关注，以防止永久性的系统发育多样性丧失。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Changes in parrot diversity after human arrival to the Caribbean

• DOI: 10.1073/pnas.2301128120
• 发表时间: 2023-10-10
• 期刊: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• 影响因子: 11.1
• 作者: Oswald，Jessica A.;Smith，Brian Tilston;LeFebvre，Michelle J.
• 通讯作者: LeFebvre，Michelle J.