The Problem of the "Prebiotic and Never Born Proteins"

TL;DR

This paper challenges the probabilistic argument that the limited set of known proteins could not have arisen naturally, by examining assumptions and suggesting fewer sequences needed for protein evolution.

Contribution

It presents considerations that reduce the assumed number of amino-acid sequences necessary for the evolution of proteins, questioning prior probabilistic constraints.

Findings

The number of amino-acid sequences needed is smaller than previously assumed.

Implicit assumptions in the probabilistic argument are questionable.

The evolution of proteins may have been more feasible than prior estimates suggested.

Abstract

It has been argued that the limited set of proteins used by life as we know it could not have arisen by the process of Darwinian selection from all possible proteins. This probabilistic argument has a number of implicit assumptions that may not be warranted. A variety of considerations are presented to show that the number of amino-acid sequences that need have been sampled during the evolution of proteins is far smaller than assumed by the argument.