Evolution of Marine Mammal Foraging Behavior Based on Ca and C Isotope Ratios in Bioapatite

基于生物磷灰石中 Ca 和 C 同位素比率的海洋哺乳动物觅食行为的演变

• 批准号: 0519052
• 负责人: David Fox
• 金额: --
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-10-01 至 2008-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0519052&HistoricalAwards=false
• 关键词: Evolution; Marine; Mammal; Foraging; Behavior

Though the trophic structure of marine ecosystems is known to haveincreased in complexity over time, methods of quantifying this change are lacking. The proposedresearch will expand upon promising preliminary work using Ca isotope ratios as paleoecologicalindicators and develop this isotopic system as a proxy for the trophic level of extinct marine mammals.By combining Ca isotope analyses with C isotope ratios, which vary with foraging habitat in marineecosystems, this project will provide a new means to examine the structure of ancient marine vertebrateecosystems. Since the trophic structure of foodwebs has a significant influence on the pathways by whichnutrients and energy move within and between ecosystems, analysis of the Ca isotope composition ofbiogenic hard parts may aid in elucidating how nutrient cycling and energy flow have fluctuated overtime. Furthermore, by expanding current knowledge of how ancient ecosystems functioned and how theydiffered from today s ecosystems, a44Ca measurements can help improve interpretations of how climaticand environmental perturbations have impacted or were impacted by the Earth s biosphere. Ultimately,this project will provide new insight into the evolution of whales, whose from a terrestrial ancestorrepresents one of the most remarkable transitions in the history of life on Earth.Although the ultimate objective of this research is to understand the role of temporal changes inforaging behavior in the evolution of Cetacea (the clade that includes living whales, porpoises, anddolphins), the influence on Ca isotope ratios of factors other than trophic level must be examined first inmodern species before Ca isotope ratios can be applied to extinct species. Samples of marine mammals infour, distantly related groups (sirenians, mustellids, cetaceans, and pinnipeds) will be analyzed as a meansof addressing the impact of phylogenetic history on a44Ca values; the degree of similarity of a44Ca valuesfor species at the same trophic level will verify whether a44Ca values reflect trophic level differencesregardless of evolutionary history. The C isotope composition of each sample will be analyzed as a proxyfor foraging habitat preference; a stronger correlation between a44Ca with trophic level rather than a13Cvalues will indicate that trophic level has a stronger influence on a44Ca values than the foraging habits ofa species. Variation in a44Ca within a single individual will be explored by analyzing the Ca isotopecomposition of multiple skeletal elements from a single individual from each of the four modern groupsof marine mammals sampled. Once the factors influencing a44Ca values in modern marine mammalshave been constrained, the Ca and C isotope composition of Eocene and Oligocene cetacean and sirenianbioapatite will be analyzed to assess the potential of this proxy for paleoecological studies. Thediversification of cetacean feeding strategies in the Oligocene should coincide with a large change ina44Ca and a13C values of cetacean bioapatite, providing a clear signal of whether original a44Ca values canbe preserved and interpreted from the fossil record. Fossil bones of sirenians will also be analyzed as acontrol for potential changes in seawater a44Ca values, since the trophic level of this group has remainedconstant over time and any changes in the a44Ca values of this group will reflect changes in seawatera44Ca values.Broader impacts. The broader impacts of this project are threefold. First, the grant will furtherthe training and development of a recent Ph.D. who will be supported as a postdoc. Under thesupervision of the PIs, this researcher will have primary responsibility for refining the methodologies,acquiring and analyzing the samples, and interpreting and disseminating the results. Second, the researchwill provide a new and potentially powerful paleoecological tool to the broader community that can beapplied to other ancient marine ecosystems and, after further development, may also have applications interrestrial ecosystems. Finally, the results will complement our increasingly detailed knowledge of whaleevolution. Once the proposed research is completed, the ecological and morphological changesassociated with the evolution of whales will be one of the best documented cases of macroevolutionarychange in the vertebrate fossil record. Given the historical place of whale origins in anti-evolutionpolemics, this research will surely have lasting impact in undergraduate and K-12 class rooms.

尽管已知海洋生态系统的营养结构随着时间的流逝而变得复杂，但缺乏量化这种变化的方法。提议的研究将扩大使用CA同位素比例作为古生物学指导者的有希望的初步工作，并将这种同位素系统作为灭绝的海洋哺乳动物的营养水平的代理。通过将CA同位素分析与C同位素比率相结合，与COSOTOPE的比例相结合，随着该项目的觅食范围，它们会在新的范围内提供一个新的项目，从而提供了一种新型的序言。由于FoodWebs的营养结构对生态系统内部和生态系统之间的能量移动的途径具有重大影响，因此对生物生成的硬性零件的Ca同位素组成的分析可能有助于阐明养分循环和能量流的加时性。此外，通过扩大当前对古代生态系统功能的知识以及它们从今天的生态系统的变化方式，A44CA测量可以帮助改善对气候和环境扰动如何影响或受地球生物圈影响或影响的解释。最终，该项目将为鲸鱼的演变提供新的见解，鲸鱼的演变是从地球生命历史上最引人注目的过渡之一，尽管这项研究的最终目的是了解暂时变化行为在Cetacea（包括CETACEA的进化）中的作用（包括生存的hales，以及其他因素，以及孔孔，以及孔孔，以及孔孔，以及孔孔，以及孔孔，以及孔孔，以及孔孔，以及孔孔，以及孔平呈相同的群别，以及某种概况，以及某种概况，以及某种情况下的范围，既有毛刺群）。在将Ca同位素比应用于灭绝物种之前，必须先检查营养水平。海洋哺乳动物Infour，远距离相关组（Sirenians，Mutellids，Cetaceans和Pinnipeds）的样品将被分析，作为解决系统发育史对A44CA值的影响的平均值； A44CA值在相同的营养水平上的相似程度将验证A44CA值是否反映了营养水平的差异，而无需进化史。每个样品的C同位素组成将被分析为觅食栖息地的偏好。 A44CA与营养水平而不是A13CVALE之间的相关性更强，这表明营养水平对A44CA值的影响要比物种的觅食习惯更强。通过分析来自采样的四个现代族组的单个个体的多个骨骼元素的CA同位分组，将探索单个个体内A44CA的变化。一旦限制了影响现代海洋哺乳动物的A44CA值的因素，将分析始新世和渐新世赤酸和渐新世的Ca和c同位素组成，以及Sirenianbioapatite，以评估该古生物学研究代理的潜力。渐新世中的鲸类喂养策略的分类应与鲸类生物磷灰石的巨大变化Ina44ca和A13C值相吻合，从而明确信号表明原始A44CA值是否可以保留并从化石记录中解释。 Sirenians的化石骨骼也将作为Acontrol分析，以实现海水A44CA值的潜在变化，因为该组的营养水平随着时间的推移而保持不变，并且该组的A44CA值的任何变化都会反映出SeaWatera444CA值的变化。Broader的影响。该项目的更广泛影响是三倍。首先，赠款将进一步培训和发展最近的博士学位。谁将作为博士后支持。在PIS的细节下，该研究人员将负责完善方法，获取和分析样品，并解释和传播结果。其次，研究意想明为更广泛的社区提供了一种新的且潜在的古生态学工具，该工具可能会吸引其他古老的海洋生态系统，并且经过进一步的发展，也可能具有相互态度的生态系统。最后，结果将补充我们越来越详细的Whaleevolution知识。一旦拟议的研究完成，随鲸鱼的演变弥补的生态和形态变化将是脊椎动物化石记录中最佳记录的麦克罗化精案例之一。鉴于鲸鱼起源于反进化论的历史地位，这项研究肯定会对本科和K-12教室产生持久影响。