Table 1.

Competing interactions and frustrated states in biological evolution

SystemFrustration-producing factors (competing interactions)Emergent functional and evolutionary features
RNAShort-range (within stem local hydrogen bonding, stacking) vs. long-range (long-distance hydrogen bonding, salt bridges) interactions between nucleotidesComplex 3D structures including ribozymes
ProteinsShort-range (Van der Waals) vs. long-range (hydrogen bonds, salt bridges) interactions between amino acid side chainsStable conformations and semiregular patterns in protein structures; allostery enabled by transitions between energetically quasi-degenerate conformations
Macromolecular complexesWithin-subunit vs. between-subunit interactionsElaborate complex organization, in particular nucleoproteins (ribosomes, chromatin)
CellsMembranes (confinement of chemicals) vs. channels/pores (transport of chemicals)Compartments and cellular machinery dependent on electrochemical gradients
Autonomous (hosts) and semiautonomous (parasites) replicatorsReplicator vs. parasite genomesSelf- vs. non-self-discrimination and defense; complex genomes of increasing size; primitive cells
Autonomous (hosts) and semiautonomous (parasites) reproducers/replicatorsHost cells and virusesInfection mechanisms, defense and counterdefense systems, evolutionary arms race; contribution to the origin of multicellular life forms
Autonomous (hosts) and semiautonomous (parasites) reproducers/replicatorsHost cells vs. transposonsIntragenomic DNA replication control; evolutionary innovation through recruitment of transposon sequences
Autonomous (hosts) and semiautonomous (parasites) reproducers/replicatorsHost cells vs. plasmidsBeneficial cargo genes, plasmid addiction systems, efficient gene exchange and transfer mechanisms
Emerging eukaryotic cellsHost (archaeal) cells vs. endosymbiont (α-proteobacteria, protomitochondria)Eukaryotic cells with complex intracellular organization
Communities of unicellular organismsIndividual cells vs. cellular ensemblesInformation exchange and quorum sensing mechanisms; replication control, programmed cell death, multicellularity
Multicellular organismsSoma vs. germlineComplex bodies, tissues and organ differentiation, sexual reproduction
Multicellular organismsDividing vs. quiescent cellsAging, cancer, death
PopulationsIndividual members vs. groupsPopulation-level cooperation; kin selection; eusocilaity
PopulationsMales vs. females (partners with unequal parental investment)Sexual selection, sexual dimorphism
EcosystemsSpecies in different nichesInterspecies competition, host–parasite and predator–prey relationships, mutualism, symbiosis
  • Those competing interactions and frustrated states that are deemed to directly contribute to MTE are shown in bold.

  • * We refrain from specifying the conflicts that drive the origin and evolution of human societies.