identifier: traitmech:000708
label: diversifying bet hedging
definition: A physiological phenotype in which a clonal microbial lineage reversibly
  interconverts between alternative cell states independently of the prevailing environment
  and before environmental change, spreading risk across unpredictable environmental
  changes through state-specific survival or reproductive trade-offs.
definition_source: DOI:10.1371/journal.pbio.1001325
trait_category: PHYSIOLOGY
term_kind: CLASS
mapping_status: PROPOSED
parent_traits:
- METPO:1000059
evidence:
- reference: DOI:10.1038/nature08504
  snippet: Here we report the de novo evolution of bet hedging in experimental bacterial
    populations.
  notes: Beaumont et al. 2009, PMID:19890329; scientific abstract, directly checked
    against publisher and source-qualified MED text, not the publisher's Editorial
    Summary. Supports experimentally evolved risk spreading by rapid phenotype switching
    under a changing selection regime. Mutational evolution of a switching genotype
    is not the same claim as mutations generating each alternative cell state. Main
    figures, supplements and raw data were not independently assessed; no gene-level
    mechanism or natural canonical exemplar is asserted.
- reference: DOI:10.1371/journal.pbio.1001325
  snippet: Our results suggest that yeast bet hedging results from multiple epigenetic
    growth states determined by a combination of stochastic and deterministic factors.
  notes: 'Levy, Ziv and Siegal 2012, PMID:22589700, PMC3348152; scientific abstract,
    directly checked against publisher, MED and full-text XML, separately from the
    Author Summary. Box 1 supplies the definition framework and explicitly leaves
    adaptive origin untested in this yeast study. The record preserves that limit:
    reversible state variation and differential stress survival do not alone establish
    evolutionary optimization. Binary states and a purely stochastic mechanism are
    not required.'
- reference: DOI:10.1038/s41467-024-46297-6
  snippet: Mobile cells grow faster but are stress-sensitive, while non-mobile cells
    prioritise stress resistance over growth.
  notes: Tang et al. 2024, PMID:38453919; scientific abstract, directly checked against
    publisher and source-qualified MED text. The Introduction and Discussion distinguish
    early diversification of Haematococcus pluvialis cultures from later stress-induced
    conversion. Growth and survival are fitness proxies, not a demonstration of optimized
    long-term geometric mean fitness. Figures, supplements and raw data were not independently
    assessed; proposed transcriptional explanations are not encoded as causal edges.
discussions:
- discussion_id: bet-hedging-scope-and-hierarchy
  prompt: Retain lineage-level risk spreading without equating all cellular heterogeneity
    with bet hedging.
  kind: CURATION_TODO
  status: OPEN
  rationale: 'The diversifying qualifier restricts this class to alternative states
    within a clonal microbial lineage; it does not cover every use of unqualified
    bet hedging. Heterogeneity, noisy gene expression or switching alone is insufficient:
    reversible states must precede the relevant environmental shift and differ in
    survival or reproductive performance across conditions. Generic stress-induced
    change, carbon-source memory, cue-triggered environmental anticipation, genetic
    resistance and ecological generalist/specialist niche breadth are not exact synonyms.
    Particular observations can overlap without making these classes equivalent or
    disjoint. Dormancy and persister formation can participate in risk spreading,
    but their presence alone does not establish it, so neither existing record is
    reparented. METPO:1000059 phenotype is the conservative parent pending upstream
    review of this lineage-level physiological disposition. This is not a sequence
    feature, individual assay result or mixed-species community property. Following
    Levy et al. Box 1, the relevant state interconversion must be independent of the
    prevailing environment; temporal precedence alone does not establish this criterion.
    Cue-triggered preparation before a later change is not sufficient. Deterministic
    age-related variation can qualify, so environmental independence does not require
    a purely stochastic switching mechanism.'
  posed_by: codex
  posed_date: '2026-10-12'
- discussion_id: bet-hedging-evidence-and-mechanism-limits
  prompt: Assess adaptive origin, natural exemplars and molecular mechanisms separately
    from the operational phenotype.
  kind: KNOWLEDGE_GAP
  status: OPEN
  rationale: This first-pass class does not assert that every cited system was selected
    for diversification or has a measured long-term fitness advantage. Levy et al.
    Box 1 distinguishes those stronger claims from its operational usage; testing
    arithmetic and geometric mean fitness requires an explicit environmental distribution
    and comparison strategy. No fixed switching rate, binary state space or universal
    protein mechanism is asserted. Canonical taxa await strain-provenance and taxonomy
    checks; causal_graphs, xrefs and synonyms are omitted. MED, Crossref and visible
    publisher links checked on 2026-10-12 exposed no correction or retraction for
    the three retained papers; commentary, review and preprint links are not independent
    experiments. This bounded check does not exclude every possible notice. Pinned/current
    METPO RDF and ignored/hidden novelty searches found no exact active or deprecated
    term; earlier research mentions remain leads, not primary records. The pinned
    ontology is unchanged.
  posed_by: codex
  posed_date: '2026-10-12'
curation_history:
- timestamp: '2026-10-12T06:39:53Z'
  curator: codex
  action: MINTED_TRAITMECH_ID
  changes: Added diversifying bet hedging with three primary DOI-backed sources and
    directly checked scientific-abstract snippets. Reserved 000708, v584 and 1066100-1066199
    after ignored/hidden worktree and pending-PR checks. Operational risk spreading
    is distinguished from evolutionary optimization; examples and mechanisms remain
    deferred. Existing traits unchanged; timestamp is the observed UTC curation decision.
  llm_assisted: true
- timestamp: '2026-10-12T07:04:27Z'
  curator: codex
  action: QUALIFIED_TRAIT_SCOPE
  changes: 'Addressed #1888: made reversible environment-independent state interconversion
    explicit in the definition and scope discussion, following Levy et al. Box 1.
    Temporal precedence alone is insufficient; purely stochastic or binary switching
    is not required. Preserved evidence and original provenance. Timestamp is the
    observed UTC correction decision.'
  llm_assisted: true
- timestamp: '2026-10-12T08:09:20Z'
  curator: codex
  action: CORRECTED_SCOPE_WORDING
  changes: 'Addressed external review #1890: corrected the inverted implication in
    the first scope discussion. Environment-independent interconversion remains required;
    a purely stochastic mechanism is not required, consistent with Levy et al. Box
    1. Preserved the definition, evidence, proposal definition and both previous events.
    Timestamp is the observed UTC correction decision.'
  llm_assisted: true