Package models and the information crisis of prebiotic evolution

TL;DR

This paper critically examines the package model for prebiotic evolution, demonstrating that it cannot resolve the information crisis because total information content remains constant despite increasing template diversity.

Contribution

It shows that the traditional package model does not solve the information crisis, as total information content is limited by replication error rates regardless of template number.

Findings

The model's viability depends on a constant total information content.

Increasing template diversity requires decreasing template length.

Total information gain in the model is effectively null.

Abstract

The coexistence between different types of templates has been the choice solution to the information crisis of prebiotic evolution, triggered by the finding that a single RNA-like template cannot carry enough information to code for any useful replicase. In principle, confining $d$ distinct templates of length $L$ in a package or protocell, whose survival depends on the coexistence of the templates it holds in, could resolve this crisis provided that $d$ is made sufficiently large. Here we review the prototypical package model of Niesert et al. 1981 which guarantees the greatest possible region of viability of the protocell population, and show that this model, and hence the entire package approach, does not resolve the information crisis. This is so because to secure survival the total information content of the protocell, $Ld$, must tend to a constant value that depends only on the spontaneous error rate per nucleotide of the template replication mechanism. As a result, an increase of $d$ must be followed by a decrease of $L$ to ensure the protocell viability, so that the net information gain is null.