Evolutionary Chemistry and Origins of Life
Our research is structured around the idea that the origin of life, can be seen as a general phenomenon that occurs when chemical ensembles in spatially structured environments have certain properties. Most important, the underlying chemistry must allow some autocatalysis so that ensembles can shift among alternative locally-stable stable states. This chemical evolution can occur even when ensembles are little more than patches in the environment and when autocatalysis depends on mechanisms other than template-replications of genetic polymers. The Baum lab uses innovative empirical and computational research to test the model (see figure). We aim to clarify conditions allowing chemical evolution to arise and to map out the process by which simple chemical evolution can eventually yield features needed for biological (Darwinian) evolution: self-bounded ensembles (individuals) and template-replicating genetic polymers.
1) Emergence of evolvable chemical mixtures
The theory we have developed suggests that out-of-equilibrium small molecule chemical mixtures can undergo long term changes in composition that resemble those seen in ecology or evolution. We conduct diverse laboratory experiments to look for evidence of these phenomena.
Mathematical1 and computational investigations2 show that chemical reaction networks are huge and include within them uncountably many autocatalytic cycles. These cycles can interact with each other much like species in biological ecosystems3 implying that dynamics of prebiotic chemical mixtures might have resembled ecological succession4.
Our basic approach is to study the behavior of prebiotic soups – mixtures of compounds that are to some degree likely to have existed before life5. We incubate periodic soups (usually minerals) and use periodic dilution-and-replenishment to keep systems out of equilibrium. We original implemented this strategy, chemical ecosystem selection6, while tracking simple chemical features, which revealed evidence of complex non-linear chemistry7. We now use high-sensitivity liquid chromatography and tandem mass spectrometry (LC-MS) to obtain extremely detailed characterization of chemical dynamics and allow inferences regarding the underlying chemical reaction network. Current work8 is following up on preliminary evidence of heritability in the absence of genes and testing the hypothesis that small molecule combinatorial chemistry tends to multi-stability and extreme sensitivity to chemical perturbations.
2) Emergence of individuality
One of the most obvious features of life is that chemical ensembles are bounded intrinsically: they make their own edges. This allows for a growth-and-division lifecycle that, among things, promotes cooperation among cellular components and suppresses cheating. We conduct computation and experimental research to better understand how individuation first arose and how primitive protocells might have evolved even in the absence of genes.
Our computational research is motivated by the cells-as-propagules hypothesis9, which proposes that, in environments subject to turnover in available sites, ecosystems chemical propagules composed capable of co-dispersing multiple cooperating autocatalytic cycles might be expected to arise and gradually acquire autonomy. We have shown that, in spatially structured environments, dispersal is an important consideration10. Now, partly in collaboration with Emily Dolson at Michigan State University, we are starting to model diverse mechanisms of co-dispersal assess whether protocells could gradually evolve rather than just pop into existence ready to grow and divide, as usually assumed. On the experimental front, graduate student Tymofii Sokolskyi is studying heritability in populations of artificial protocells as indicated by temporal dynamics11 and responses to artificial selection12.
3) Emergence of genetic systems
Modern life depends on sets of polymers (proteins and nucleic acids) that cooperate to enable cells to grow and divide. By catalyzing specific reactions, polymers direct flux through metabolism and into the generation of new polymers. Moreover, nucleic acids have a specific ability to catalyze the formation of complementary strands, which serves as the basis for genetic inheritance. We are using experiments and computational modeling to understand how communities of cooperating polymers can emerge and complexify.
With collaborator, John Yin, we have used recursive wet-dry cycling (with dilution and replenishment) to elicit polymer formation and look for evidence of autocatalytic feedback. These investigations are at an early stage but could shed light on the intrinsic dynamics of polymerization cascaded. This work is complemented by a new experimental approach we are developing with support from the Alfred P. Sloan foundation. In a collaboration with David Beebe, a microfluidics engineer, we impose artificial selection on the emergent properties of droplets containing polymer populations. Combined with mathematical analysis of abstract polymerization systems13 and computational modeling of ecosystems of cooperating, catalytic nucleic acids14 we believe we will better understand how complex genetic systems composed of many long and highly efficient polymers can bootstrap themselves into existence during origins of life.
1 Gagrani et al. 2024; Gagrani and Baum 2025
2 Peng et al. 2022
3 Peng et al. 2020
4 Baum et al. 2023
5 Vincent et al. 2022
6 Baum and Vetsigian 2016
7 Vincent et al. 2019
8 Sokolskyi et al. 2024
9 Baum 2015
10 Plum et al. 2025
11 Sokolskyi et al. 2023
12 Sokolskyi et al. 2026
13 Gagrani and Baum 2025
14 Peng et al. 2026