Form Submission: Participation Entry

Living organisms must fulfill various requirements. Functionally, an organism must be able to perform metabolic processes to transform energy and matter. Informationally, an organism’s genome must contain the instructions to enact these functions and to pass them on to future generations. Structurally, an organism’s form, constructed from cells with subcellular anatomy, must provide a scaffold for these structural and informational processes. Organisms show remarkable diversity along all three axes: functionally, organisms use disparate metabolic processes to exploit a myriad of energy sources; informationally, organisms’ genomes differ greatly in content and architecture, spanning seven orders of magnitude in total size; structurally, organisms range from single cells less than a micron across to expansive organisms built of billions to trillions of much larger cells. Because organismal growth and fitness depends on the rates of resource production and consumption, metabolic rates are thought to directly impact ecological and evolutionary performance. Across all life metabolic rates vary by orders of magnitude, and metabolic rates are determined by the sizes and arrangement of cells. Thus, because of biophysical packing constraints and because of the relationship between cell surface area and volume, more, smaller cells can support higher metabolic rates than few, larger cells. Across all life, cell size is fundamentally constrained by genome size. Thus, the scaling of genome size and metabolism may be a fundamental rule of life governing the structure and function of organisms, with implications for the relative successes of different species, the distribution of organisms in space, and the flow of energy and matter through ecosystems. Furthermore, the scaling of genome size and metabolism unifies the structural, functional, and informational qualities of living organisms and provides a foundation for explaining patterns of evolutionary innovation and ecological success.