Evaluating the Influence of Scale on Paleoecological Results

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Paleontologists and biologists have struggled with the question "why are there this many species in this place?" for over a century without achieving a consensus. In the face of a global environmental crisis, this question has become critical; we must understand the drivers of biodiversity, ecosystem stability, and extinction. Each study of fossil and biological biodiversity collects data at specific spatial, time, or numerical scales appropriate to each study, but meta-analysis of multiple studies, each with data collected at different scales have proved to be problematic at best and grossly inaccurate at worst. Scientists urgently need to address the issue of scale so that we can accurately understand biodiversity and its implications in addressing conservation. My research will investigate the effects of scale in sampling on analyses and results. Specifically, I am asking: 1) do results change from smaller to larger scales? For example, if an environmental parameter influences the number of species collected in a small sample, would an increase in sample size identify the same environmental factor, or would the analysis point to an entirely different parameter? 2) If results change with an increase in scale, is the change real, coming from an actual ecological/evolutionary driver working at different scales, or to a mathematical artifact that arose from analyzing samples of different scales? Research on present-day species are critical to understanding present-day biodiversity, but these projects are undertaken on ecosystems already impacted by humans. The discipline of conservation paleobiology, which looks at fossil systems to better understand and help restore or preserve modern biodiversity, has shown promise in recovering pre-human-impact, baseline conditions and information of how species respond to environmental crises. Therefore, my lab and I will investigate how scale influences the outcomes of biodiversity research using not only modern marine invertebrate species, but also the fossils of ancient marine shelled animals. The research consists of parallel studies from two time-regions known for exceptional fossil preservation. 1) My lab will compare present-day samples of mollusc shells of Florida to fossil mollusc shells from the past 5 million years (Plio-Pleistocene) in the same area. 2) To investigate if results are generalizable across larger temporal scales, my lab will also collect brachiopod shells from approximately 370 to 390 million years ago (Devonian) of western Canada. The impacts of this research will be substantial for studies in biodiversity and conservation paleobiology, but have broader implications. Any discipline or study that requires sampling, and those samples are affected by space, time, number, or any other quantifiable parameter, are subject to the same sorts of problems imposed by scale and will benefit from the results of my research.