Metabolic scaling theory (MST) is an attempt to link physiological processes of individual organisms with macroecology. It predicts a power law relationship with an exponent of -4/3 between mean individual biomass and density during density-dependent mortality (self-thinning). Empirical tests have produced variable results. and the validity of MST is intensely debated. https://www.marketingjeunesse.com/product-category/tonucia-replumping-shampoo/