The low polydispersity of PI3K-SH3 fibrils is the result of kinetic and thermodynamic selection. It is interesting to consider that none of the single point mutations we characterised stabilizes the amyloid structure of PI3K-SH3. Together with the efficient templating, as reflected by the well-defined TSE, these finding suggest that its free energy landscape efficiently directs this protein towards its global free energy minimum. Recent findings of strain evolution during tau 56 and hIAPP aggregation reactions suggests that the aggregation reaction is a competition of different possible aggregate conformations, subject to kinetic and thermodynamic selection. Such selection might also be at play for PI3K-SH3, with the outcome of a single fibril morphology, due to the lack of degenerate misfolding pathways. Significant questions arise from these findings as to how the energy landscape appears for more polymorphic amyloid systems. The novel approach to elucidating misfolding mechanisms that we outline in this work is also applicable to such more complex systems, because in polymorphic systems, the thermodynamic and kinetic experiments can be expected to be dominated by the most stable and most rapidly growing morphologies, respectively. The mechanism of formation of the non dominant morphologies can be studied if they can be sufficiently purified or enriched.