Assessing predation through time and space

通过时间和空间评估捕食

• 批准号: 372615-2009
• 负责人: Leighton, Lindsey
• 金额: $ 1.6万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2012
• 资助国家: 加拿大
• 起止时间: 2012-01-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=496903
• 关键词: Assessing; predation; through; time; space

Predation, the act of an organism killing another for food, is believed to influence the evolution and diversity of species greatly. Given the modern biodiversity crisis (70 species per day go extinct), we must understand better those factors that influence life's diversity. However, many influences, including predation, are hard to estimate, especially in marine settings, where it is difficult to count acts of predation directly. Similarly, direct observations of the past are impossible, but assessing predation in the fossil record would greatly expand our knowledge. Thus, we need a means of estimating predation without direct observations. One solution is to use traces of predation, such as scars on prey shells, to estimate predation. This research has two goals: first, to test the validity of using predation traces as an estimate of predation intensity, using in-field modern experiments; and second, to apply what was learned from the modern experiments to the fossil record to test for the influence of predation during the Mid-Paleozoic (380-290 million years). The modern component of the research will involve marking shelled invertebrates at multiple localities. At each locality, there will be a caged zone excluding predators and an uncaged zone; the difference in deaths between the two zones is attributed to predation. This mortality rate will be compared to rates of various predatory traces at each locality to determine if any traces successfully track mortality. If so, traces can be used to compare predation intensity from place to place, and through time. The paleontological component of the study will use the valid predation traces to test if the Mid-Paleozoic was a time of increasing predation intensity, and if Mid-Paleozoic marine invertebrates evolved new shapes and "armor" in response to predation, by comparing changes through time in trace activity and prey shape. Mid-Paleozoic organisms were not closely related to modern organisms, so if Mid-Paleozoic and Recent organisms were both influenced by the same factors, such a result would be more general, and thus of greater use to biology and conservation.

捕食是一种生物为了食物而杀死另一种生物的行为，被认为对物种的进化和多样性有很大的影响。 鉴于现代生物多样性危机（每天有70个物种灭绝），我们必须更好地了解影响生命多样性的因素。 然而，包括捕食在内的许多影响很难估计，特别是在海洋环境中，很难直接计算捕食行为。 同样，直接观察过去是不可能的，但评估化石记录中的捕食行为将大大扩展我们的知识。 因此，我们需要一种在没有直接观测的情况下估计捕食的方法。 一个解决办法是使用捕食的痕迹，如猎物壳上的疤痕，以估计捕食。 这项研究有两个目标：第一，使用现场现代实验来测试使用捕食痕迹作为捕食强度估计的有效性;第二，将从现代实验中学到的知识应用于化石记录，以测试中古生代（3.8 - 2.9亿年）捕食的影响。 这项研究的现代组成部分将涉及在多个地点标记有壳无脊椎动物。 在每个地点，将有一个笼区，不包括捕食者和一个非笼区;两个区域之间的死亡差异归因于捕食。 这个死亡率将与每个地点的各种掠夺痕迹的比率进行比较，以确定是否有任何痕迹成功地追踪死亡率。 如果是这样，痕迹可以用来比较捕食强度从一个地方到另一个地方，并通过时间。 该研究的古生物学部分将使用有效的捕食痕迹来测试中古生代是否是捕食强度增加的时间，以及中古生代海洋无脊椎动物是否进化出新的形状和“盔甲”来应对捕食，通过比较痕迹活动和猎物形状随时间的变化。 中古生代生物与现代生物的关系并不密切，因此，如果中古生代和现代生物都受到相同因素的影响，这样的结果将更普遍，因此对生物学和保护更有用。