The evolution of allometric outliers
The background selection of metabolism can explain allometric outliers like shrews and bowhead whales
The number of generations through which a given lineage is selected is an essential factor that affects the current evolutionary stage of the species. This is maybe best illustrated by species that evolve a small or large body mass at an early stage relative to the other species in a clade. These species will evolve over a larger or smaller number of generations that the main clade and, thus, they will have a tendency to evolve a higher or lower metabolic rate.
This evolution may explain shrews (
These outliers from typical Kleiber scaling do not reflect adaptations in a traditional sense. Instead, they reflect differences in natural selection time; where each lineage has its own timescale that is defined by the number of generations it evolves.
The natural selection of metabolism explains curvature in fossil body mass evolution
The natural selection of metabolism explains curvature in allometric scaling
- George, J.C. 2009. Growth, morphology and energetic of bowhead whales ( Balaena mysticetus). (Thesis, Ph.D.). University of Alaska, Fairbanks.
- Platt, W.J. 1974. Metabolic rates of short-tailed shrews. Physiological Zoology 42:75--90.