Generalist versus Specialist Self-Replicators.

Darwinian evolution, including the selection of the fittest species under given environmental conditions, is a major milestone in the development of synthetic living systems. In this regard, generalist or specialist behavior (the ability to replicate in a broader or narrower, more specific food environment) are of importance. Here we demonstrate generalist and specialist behavior in dynamic combinatorial libraries composed of a peptide-based and an oligo(ethylene glycol) based building block.

Selection of diverse polymorphic structures from a small dynamic molecular network controlled by the environment.

The complex interplay between systems and their environment plays an important role in processes ranging from self-assembly to evolution. Polymorphism, where, from the same ingredients different products can be formed, is likely to be an important enabler for evolutionary adaptation. Environmental pressures may induce polymorphic behaviour, where different pressures result in different structural organisation.

Spontaneous Emergence of Self-Replicating Molecules Containing Nucleobases and Amino Acids.

The conditions that led to the formation of the first organisms and the ways that life originates from a lifeless chemical soup are poorly understood. The recent hypothesis of "RNA-peptide coevolution" suggests that the current close relationship between amino acids and nucleobases may well have extended to the origin of life. We now show how the interplay between these compound classes can give rise to new self-replicating molecules using a dynamic combinatorial approach.

Emergence of Compartments Formed from Unconventional Surfactants in Dynamic Combinatorial Libraries.

Assembly processes can drive the selection of self-assembling molecules in dynamic combinatorial libraries, yielding self-synthesizing materials. We now show how such selection in a dynamic combinatorial library made from an amphiphilic building block which, by itself, assembles into micelles, can yield membranous aggregates ranging from vesicles to sponge phases. These aggregates are made from a mixture of unconventional surfactant molecules, showing the power of dynamic combinatorial selection approaches for the discovery of new, not readily predictable, self-assembly motifs.

Existing Self-Replicators Can Direct the Emergence of New Ones.

The study of the interplay between different self-replicating molecules constitutes an important new phase in the synthesis of life and in unravelling the origin of life. Here we show how existing replicators can direct the nature of a newly formed replicator. Starting from the same building block, 6-ring replicators formed when the mixture was exposed to pre-existing 6-membered replicators, while pre-formed 8-membered replicators funneled the building block into 8-ring replicators.

Parasitic Behavior of Self-Replicating Molecules.

Self-replication plays a central role in the origin of life and in strategies to synthesize life de novo. Studies on self-replication have focused mostly on isolated systems, while the dynamics of systems containing multiple replicators have received comparatively little attention. Yet most evolutionary scenarios involve the interplay between different replicators.