Amino acids have amide linkage HN-C=O. Are other linkages possible, and exist, such as for plants, and for microbial world? Has nature had the opportunity to try other combinations, and based on energetics and kinetics, selected (in part?) such amide linkage as most robust to perturbation i.e. stable? Chemical reactions occur over ~10^-9/sec – 10^-15/s; so ideally perhaps 10^9-15 reactions per sec, which dwarfs 4 x 10^9 years.
Again is stability (as for a dryer surface?) a co-evolving selection factor essential in any origin of life scenario, whether here or for another world – a dryer Martian scenario? Thus would initial geological nitrogen fixation and subsequent amide linkage seem general features typical for life anywhere? Is an amide bond more stable than most alternative choices? Hence a chemical bond example of importance, for such selection for stability concept, for early evolution of life here, and throughout the universe? Nature has had plenty of time to explore the space of all chemical possibilities on this planet. So wouldn’t such sparse sampling suffice for exploring a general universal chemistry approach – giving rise to life?
Pattabtraman V.R., Bode J.W., Rethinking Amide Bond Synthesis, Nature Vol 480 p. 471, Dec. 22/29, 2011, and references therein.