The selection of a single molecular handedness, or homochirality across all living matter, is a mystery in the origin of life. Frank’s seminal model showed in the ’50s how chiral symmetry breaking can occur in nonequilibrium chemical networks. However, an important shortcoming in this classic model is that it considers a small number of species, while there is no reason for the prebiotic system, in which homochirality first appeared, to have had such a simple composition. Furthermore, this model does not provide information on what could have been the size of the molecules involved in this homochiral prebiotic system. Here, we show that large molecular systems are likely to undergo a phase transition toward a homochiral state, as a consequence of the fact that they contain a large number of chiral species. Using chemoinformatics tools, we quantify how abundant chiral species are in the chemical universe of all possible molecules of a given length. Then, we propose that Frank’s model should be extended to include a large number of species, in order to possess the transition toward homochirality, as confirmed by numerical simulations. Finally, using random matrix theory, we prove that large nonequilibrium reaction networks possess a generic and robust phase transition toward a homochiral state.

在所有生命物质中选择单个分子手性或同手性，是生命起源中的一个谜。弗兰克的开创性模型在 50 年代展示了如何在非平衡化学网络中发生手性对称性破坏。然而，这个经典模型的一个重要缺点是它考虑的物种数量很少，而最初出现同手性的益生元系统没有理由具有如此简单的组成。此外，该模型没有提供有关该同手性益生元系统中所涉及的分子大小的信息。在这里，我们表明大分子系统可能会经历向同手性状态的相变，因为它们包含大量手性物质。使用化学信息学工具，我们量化了给定长度的所有可能分子的化学宇宙中手性物种的丰富程度。然后，我们建议弗兰克的模型应该扩展到包括大量的物种，以便拥有向同手性的过渡，正如数值模拟所证实的那样。最后，使用随机矩阵理论，我们证明大型非平衡反应网络具有向同手性状态的通用且稳健的相变。