Correlation Between Ecospace and Metabolic Rate of Marine Organisms Through Geologic Time

Abstract:

Marine organisms are the most abundant fossils scientists have discovered in the fossil record. Various factors affect the survival rate of individual organisms and entire genera including metabolic rate, genetic diversity, environmental availability, and ecology. We however chose to focus our attention on studying mean metabolic rates in correlation to life modes. A marine organism’s life mode is determined by three criteria: tiering, motility, and feeding mechanism. We believe an organism's life mode has an effect on its survivorship, especially since ecospace is the "primary determinant of routine metabolic rate for marine organisms” (Seibel & Drazen 2007). Using the metabolic equation, we were able to plot metabolic rate changes for various life modes over time. Seibel and Drazen (2007) explain that "metabolic variation in the ocean results from interspecific differences in ecological energy demand," thus allowing us to hypothesize that with different combinations of life modes, different marine organisms will have varying metabolic rates. To further compare our data, we created a heatmap to show the change in metabolic rates over the last 540 million years. Based on the collection of data, metabolic rates of marine organisms have shown an increasing trend. When analyzing ecospaces, pelagic (living in the water column), free moving organisms have relatively high metabolic rates in comparison to other modes of tiering. In other life modes, there’s a general trend of genera maintaining a stabilized and moderate metabolic rate that is neither extremely high nor low.