Behind the scene of body mass allometries

The inter-specific body mass allometries are predicted by population dynamic feedback selection (Witting, 1995, 2017). This selection is an entangled process that links the frequency-independent selection of the physiology to the density-frequency-dependent feedback selection of the intra-specific interactive competition.

In the release on bioRxiv I use the covariance among life history estimates for 90% of all birds and mammals to visualize some of the underlying natural selection causes. This illustrates:

How the primary selection of resource handling and mass-specific metabolism generates the net energy of individuals.

How the selected net energy generates population dynamic feedback selection, where intra-specific interactive competition selects body masses that scale in proportion with net energy on the timescale of natural selection.

How the feedback selection of mass buffers the ecological variation in survival.

How the primary selection of metabolism explains a curvature, where the residual mass-specific metabolism---relative to the expectation of the mass-rescaling allometry---is a declining function of mass in terrestrial placentals and birds, but not in marsupials and bats.

How the joint selection of body mass and optimal foraging select the exponents of body mass allometries from the dominant spatial dimensionality of the feeding ecology (Fig. 1).

Fig. 1 Allometric representation of the invariant population regulation by local exploitation (top plot) and interference competition (middle plots), with the theoretical predictions (the 2 red lines) solved in the bottom plot for the mass-rescaling exponents for home range and mass-specific metabolism for 1D, 2D and 3D ecological interactions. For details see Witting (2022).

References

• Witting, L. 1995. The body mass allometries as evolutionarily determined by the foraging of mobile organisms. Journal of Theoretical Biology 177:129--137, https://doi.org/10.1006/jtbi.1995.0231.
• Witting, L. 2017. The natural selection of metabolism and mass selects allometric transitions from prokaryotes to mammals. Theoretical Population Biology 117:23--42, https://dx.doi.org/10.1016/j.tpb.2017.08.005.
• Witting, L. 2022. Behind the scene of body mass allometries. Preprint at bioRxiv https://dx.doi.org/10.1101/2022.09.13.507740.