For much of it’s existence biology has been a qualitative science without a unifying theory underlain by mathematics.
All the processes of life, even sleep, require energy. The amount of energy an organism needs to sustain basic operation is governed by it’s metabolism.
As the size of an organism increases, it’s metabolic rate only increases by a factor of 3/4. This provide every doubling in size with an energy savings of 25%.
Almost all biological scaling laws are multiples of 1/4. This thread leads to a commonality among the diverse aspects of life and provide a strong case for a uniting principle that’s far less random than natural selection.