Retrieved evolutionary and biochemical literature confirms that the structural and sequence evolution of proteins is heavily restricted by historical contingency, epistasis, and underlying physico-chemical constraints.
The claim posits that protein usage in life is restricted by evolutionary contingency and chemical constraints. Papers [0], [1], and [10] provide direct evidence that physico-chemical properties, thermodynamic constraints, epistasis, and path-dependent historical contingency heavily dictate protein sequence spaces and evolutionary outcomes. No papers refute this premise.