Dead resident cells may feed invasive lineages during epithelial repair

The train of thought that ends in this hypothesis. Each stage is the reason the next exists. The master question narrows to a goal, the goal to an unknown nobody has closed, the unknown to the hypothesis proposed here. Every step below says what it rests on and what carries it.

Two established results predict opposite outcomes, and both cannot be right.

Does suppressing expanding cell families in aging human linings promote invasion or improve repeated repair?

The engine's own statement of the hypothesis, in full.

SCOUT 2 from decomposition biogeochemistry and isotope-resolved trophic ecology, conditional: In aging human epithelium, killing a resident while retaining locally accessible corpse material may create an incremental nutrient pulse that a pre-existing invasive lineage uses through assimilation or catabolic/energetic maintenance to support extra survival or proliferative output during repair. This is material feeding only if access to and metabolic use of that pulse causally support the extra output at a quantitatively plausible scale. Extraction that carries biomass away, prompt apoptotic clearance and lysis with retained debris are different perturbations; physical removal does not inevitably supply nutrients. Viable or growth-suppressed residents can already secrete metabolites, so the claim concerns an incremental death-derived flux, not zero baseline transfer. A functionally irrelevant killed lineage could supply the same effect only if the chemical composition, accessible amount, death mode, clearance and local uptake are equivalent. Nutrient-driven growth can coexist with instructive death signals, loss of daughter displacement, fusion-mediated arrest or matrix changes, and need not produce anatomical invasion. Adequate functional replacement might improve tissue quality after removal while an acute feeding contribution occurs. No macrophage Arg1/ODC pathway is assigned to epithelial invaders; the trophic transfer remains unverified. Any effect on dangerous clone fractions must be measured separately from material assimilation and absolute output.

Every other hypothesis the engine wrote for the same gap, and the observation that would separate the two.

• Rival 01 of 03

  Cell fusion may restore growth control through resident genes in aging epithelial tissue
  What would separate them

  Cell fusion may restore growth control through resident genes in aging epithelial tissue predicts: Proposed common-condition test: begin in sterile immune-free older-donor organotypic mosaics of one specified epithelial site, with traceable resident/invader nuclear genomes, measured local contacts, successful heterotypic replacement, baseline nutrient delivery, functional permeability and matrix. First live-track two viable parental cells becoming one viable hybrid, then establish nuclear organization, phased parental genomes, copy number/ploidy and subsequent fate; exclude doublets, engulfed nuclei, undegraded phagocytosed material, label or DNA transfer and transient colocalization. Quantify assay recovery and whether hybrid incidence and the descendants restrained could account for the field-level effect; an undetected rare event gives a sensitivity-dependent bound. Authentic fusion must precede durable arrest, but a necessary but not uniquely sufficient allele-dependence test is loss of a nominated functional resident allele within an established hybrid followed by release of arrest, and allele-specific restoration followed by restored restraint, with matched ploidy, fusion history and generic fusion-stress controls, measuring allele-dependent checkpoint changes without matching them away. Compare appropriate same-ploidy fusion controls to separate functional allele rescue from generic extra-DNA or fusion stress. If allele identity remains unknown, report fusion-associated arrest only. After that, a validated resident-specific fusion block should reduce new protective hybrid formation and increase viable invader-derived output relative to rescue, provided adhesion, polarity, secretome, local encounter geometry, replacement hazard, nutrient access and barrier function remain comparable. Test a new invader challenge separately from already formed hybrids. Division-arrested viable residents should retain only the fusion-attributable protection within the window where actual encounters, fusion and mature function persist. Track late chromosome loss, escape, mature contribution and basement-membrane crossing independently of arrest and cell number. A selective fusion/allele null with adequate event detection limits the proposed contribution in this setting; generic ploidy-dependent arrest favors a hybrid-stress alternative. Factorial matrix swaps can reveal an additional matrix contribution, including retained soluble factors, ligands and geometry; they do not eliminate complementation unless validated fusion/allele contrasts add no effect within those matrix strata. Additional required discriminators and bounded interpretations: Compare tracked fates, absolute growth and post-colonization balance in matched normal and tumor contexts with recorded genotypes and perturbation/rescue. Independently test interlineage competition and serial mature/barrier function; a fitness sign reversal alone neither validates any native candidate nor predicts older-human cancer prevention. In the same older-donor epithelial model compare retained versus removed residents with matched initial wounding and adequate functional replacement, and separately vary immune presence when feasible. Track resident–invader contacts, direct losses, basal extrusion, matrix and mature function. Resident protection is supported only as a measured contribution after removal-induced injury alternatives are tested; immune-free behavior alone does not establish in-vivo immunity irrelevance. Compare genotype-resolved survival and fate under recorded inflammatory exposure versus comparable noninflamed conditions, with functional perturbation/rescue and serial mature/barrier outcomes. Prospectively track cancer outcomes separately. Any colitis-context resistance prediction does not imply an age-only benefit or make a resident universally protective. Factorially vary defined matrix chemistry/architecture and selective signaling perturbation/rescue within a recorded genotype and matched repair context; measure actual crosslinks, focal signaling, basement-membrane crossing, mutation acquisition and wound strength separately. A matrix contribution can coexist with all four native mechanisms and does not establish absence of new mutations merely because none were intended. First calibrate recovery and live-track spontaneous two-parent-to-one viable hybrid events, phase parental nuclear genomes and copy number, and follow viability and arrest before attempting allele tests. If none are detected, give a tissue/window/recovery-dependent upper bound; missing or insufficiently detectable events leave wider-subset support unknown. Conditional on viable selective edits, physiological restoration of the nominated deficient function should reinstate allele-mediated restraint, whereas matched controls and independent edits test dosage or linked-state alternatives. Measure checkpoint changes as possible mediators, distinguishing them from generic fusion stress. If selectivity, viability or defect identity cannot be established, report allele-associated arrest or unresolved identification rather than rejection or proven complementation. Estimate incident hybrid events per time and their counterfactual viable descendant output avoided per event with uncertainty, including unfused invaders and hybrid persistence/loss. Integrate these contributions through repairs and compare with the observed field effect; sustained arrested-hybrid accumulation alone cannot account for a formation-mediated protective flux. Before the contrast, pilot and prespecify a window based on actual local contacts, fusion incidence, resident allele expression and mature/barrier function, then independently validate those conditions during the comparison. Retained fusion-attributable protection in that window does not predict months–years of adequate replenishment; follow repeated repair separately and call the isolated comparison inconclusive if its controls fail. Compare cumulative viable invasive descendants, hybrid persistence/escape and mature tissue contribution across successive repairs, with late chromosome and phenotype tracking. Report the observed horizon and remaining tail uncertainty explicitly; no early arrest or arbitrary finite horizon certifies long-term safety. Current finding-specific qualification: The avoided output of a fused invader is an unobserved counterfactual: an arbitrary unfused invader need not be exchangeable because fusion may select contact histories and cell states. A formation-mediated field contribution remains conditional on a justified comparable-ancestry/history contrast, not on hybrid prevalence. Constrain avoided descendant output using comparable ancestral lineages and pre-event contact/state histories together with selective formation loss/rescue; report residual selection uncertainty and sensitivity bounds if comparability fails. Integrate incident events, counterfactual output, hybrid persistence/loss, late escape and unfused descendants over the same horizon. No event frequency or quantitative protective effect is supplied.

• Rival 02 of 03

  Resident daughter cells may restrain epithelial invaders by replacing their renewing positions
  What would separate them

  Resident daughter cells may restrain epithelial invaders by replacing their renewing positions predicts: Proposed common-condition test: in a sterile immune-free older-donor epithelial mosaic of one site, track a complete resident–invader boundary fate ledger: division, daughter retention and differentiation, migration, extrusion direction, death, vacancies and actual replacement of viable invader renewing positions. Keep invader genotype, initial lineage composition, matrix, baseline nutrients and functional permeability comparable and measure local contact geometry, density, cell size, tension proxies and signaling. First test whether gross J_R predicts directly observed h_RI at all. Then reversibly alter resident output with a resident-autonomous perturbation and rescue during the measured window before mature function or coverage diverges, with direct invader-exposure controls. If the mechanism operates, a reduction in successful h_RI should reduce position-loss events and increase absolute renewing-invader growth by the event-accounted amount when other rates are unchanged; restoring h_RI with competent fusion-incompetent cells should restore that component of restraint. Equal J_R alone does not establish equivalent replacements, and no mutation-count-independent invasion claim is made without equivalent contacts, hazards and function. Estimate parameters from mutually exclusive observed fates, predict held-out episodes, and vary geometry explicitly rather than absorbing every result into kappa_R. Gross production changes with no h_RI change and no growth effect favor a contact/occupancy explanation over a transferable gross-flux law. Coupled mechanical and replacement effects support spatial turnover competition and limit an independent constant-coefficient model. Measure mature output and next-cycle reserve independently; a lower g_I cannot compensate for their deterioration. If toxin or feeding interruption removes an ablation-associated excess while h_RI stays low, this limits flux loss as a sufficient or dominant cause only when invader growth capacity is preserved. Nutrients can increase lambda_I or survival enough to overcome high h_RI without disproving displacement. Cross matrix strata that preserve both lineages and allow events; matrix effects may alter h_RI or other rates and can coexist, while a selective h_RI null bounds this contribution. Report SPV_9 with denominator growth and anatomical crossing separately. Additional required discriminators and bounded interpretations: Before observing held-out net growth, estimate time/geometry-conditioned rate relationships on other repairs, then integrate their predicted local trajectories and propagate event-recovery, parameter and ambiguous-fate uncertainty. Compare predicted absolute I and separate tissue clone fractions with observations. A failed stationary approximation limits that reduction, not the possibility of displacement; post hoc reconstruction from the same outcome episode is bookkeeping, not predictive transfer. Follow P_R(t), mature daughter production, D_R survival/lifespan, tissue-specific mature function, growth control and reserve available at the next repair jointly. Integrate mature inflow and loss over time; a lower renewing-invader growth rate or higher J_R does not establish beneficial aging renewal or adequate specialization. Track divisions, daughter states, nondivision loss and mature survival separately; audit migration/dedifferentiation and include their net flows or restrict the model to a justified closed interval. Estimate time/geometry-conditioned rates and prospectively integrate held-out repair trajectories with uncertainty, preserving specialized function as an independent outcome. Directly count gross progenitor daughters per measured area/time and separately follow which reach and causally replace viable invader positions. Record changing area and boundaries; compare J_R with the event-resolved hazard in held-out geometry/time strata, allowing no relation or changing kappa_R. Freeze training-derived time/geometry relationships and predictive uncertainty before held-out episodes, including reciprocal replacement and repair-stage changes; use observable starting state and prespecified inputs. Recounting all held-out fates afterward checks accounting only. If no useful stable relation survives, retain event-caused displacement conditionally and reject or bound that transportable reduction, not replace its mechanism. Prespecify invader-derived hybrid membership and count each viable descendant once in a lineage numerator, track renewing and differentiated compartments and denominator dynamics, and report SPV_9 per year separately from absolute growth and crossing. Check observed count consistency and uncertainty; changing fractions or mutation counts alone cannot establish malignancy or whole-human aging benefit. Compare tracked fates, absolute growth and post-colonization balance in matched normal and tumor contexts with recorded genotypes and perturbation/rescue. Independently test interlineage competition and serial mature/barrier function; a fitness sign reversal alone neither validates any native candidate nor predicts older-human cancer prevention. In the same older-donor epithelial model compare retained versus removed residents with matched initial wounding and adequate functional replacement, and separately vary immune presence when feasible. Track resident–invader contacts, direct losses, basal extrusion, matrix and mature function. Resident protection is supported only as a measured contribution after removal-induced injury alternatives are tested; immune-free behavior alone does not establish in-vivo immunity irrelevance. Compare genotype-resolved survival and fate under recorded inflammatory exposure versus comparable noninflamed conditions, with functional perturbation/rescue and serial mature/barrier outcomes. Prospectively track cancer outcomes separately. Any colitis-context resistance prediction does not imply an age-only benefit or make a resident universally protective. Factorially vary defined matrix chemistry/architecture and selective signaling perturbation/rescue within a recorded genotype and matched repair context; measure actual crosslinks, focal signaling, basement-membrane crossing, mutation acquisition and wound strength separately. A matrix contribution can coexist with all four native mechanisms and does not establish absence of new mutations merely because none were intended. Use time-resolved boundary imaging plus selective resident output/incorporation perturbation and rescue, comparing the ordering of viable position occupancy, incorporation and invader exit. Prespecify uncertain-order cases and bound their influence; preserved area or gross J_R alone cannot identify replacement causation. Calibrate fate observation and missed events; report growth bounds under plausible assignments of ambiguous events without allocating them to fit the equation. Track displaced descendants as viable differentiated, basally displaced, dead or unresolved separately: loss from the renewing compartment is not automatically loss of the clone or anatomical safety. Current finding-specific qualification: The exponential compartment trajectory applies to a deterministic or justified conditional-mean reduction with homogeneous prescribed rates and represented flows; it is not a realized rare-clone trajectory or an extinction law. For random history-dependent rates, dE[I_s]/dt=E[g_s I_s]+E[net flows], and E[g_s I_s] generally differs from E[g_s]E[I_s]. A product-of-means closure requires independent justification. Prespecify and validate the closure on training repairs or integrate an explicit history-dependent stochastic model; propagate event, rate and demographic variability into held-out expected counts and outcome distributions. Report realized counts and extinction separately, without replacing the already defined time-local hazard by the pooled interval estimator. Compare equally prespecified contact/occupancy models. Match baseline mechanics; measure mechanics caused by daughter incorporation as part of its total displacement effect instead of clamping that mediator. A failed closure or proportional hazard reduction limits that reduction, not event-caused displacement.

• Rival 03 of 03

  Loss of mucosal barriers may let microbial toxins create mutations that drive invasion
  What would separate them

  Loss of mucosal barriers may let microbial toxins create mutations that drive invasion predicts: Proposed common-condition test: use a defined older-donor intestinal epithelial mosaic supporting documented luminal microbial contact and repair, with banked, deeply characterized ancestral lineages split across conditions. Cross retention, viability-preserving suppression and controlled small-area removal with verified toxin-competent, toxin-deficient and complemented producer conditions plus sterile controls. The matched reagent pair is an experimental target: verify microbial growth, metabolism, adhesion, community composition and proximity; equal bacterial counts are not equal delivered dose. Match initial deletion, non-toxin injury, starting producer burden, baseline nutrients, initial corpse material and matrix; downstream toxin-induced corpse release is not matched away in the total-effect arm. Measure functional permeability and local toxin activity/contact over time and do not force downstream toxin-mediated injury equal, because it lies on the proposed causal path. First establish whether removal actually increases delivered exposure and DNA adducts/damage in surviving renewal cells. If it does, follow barcodes, repeated samples and descendant phylogenies to nominate sequence changes acquired after exposure and before phenotype, reporting deep-baseline detection limits rather than claiming every rare pre-existing subclone was absent. A new mutational signature or passenger plus expansion is insufficient. After toxin withdrawal, compare descendants in a shared uninjured niche and matrix; reconstruct a nominated acquired lesion in the appropriate ancestral background or correct it in the descendant, with matched genetic controls, to test causal invasive behavior and possible cooperation with pre-existing drivers. Under the hypothesis, specific toxin interruption reduces the acquired-lesion-mediated component, and restoration of verified delivered exposure is predicted to restore its population-level contribution under a viable exposure regime, not the identical lesion or descendant in every replicate. Toxin dependence alone can also reflect selective killing or growth of pre-existing invasive lineages; ancestry and lesion causality distinguish these routes. Sterile or toxin-negative arms should lack this toxin-mediated new-lesion component, while other release mechanisms can persist. A finite negative result bounds the tested dose/time and detectable lineage frequency, not all late events. Measure absolute descendant production, clone fractions with denominator, mature barrier recovery and basement-membrane crossing separately. Matrix-dependent invasion without required new causal lesions supports a matrix contribution and can coexist with genotoxicity. Additional required discriminators and bounded interpretations: Measure local delivered dose, activity/contact, adducts/damage, cell death/arrest and surviving descendant lesions in banked ancestral lines under matched toxin-deficient and complemented conditions. Bound pre-existing ancestry and require separate lesion-function evidence before predicting invasive descendants; current microbiome composition cannot establish past exposure. Compare tracked fates, absolute growth and post-colonization balance in matched normal and tumor contexts with recorded genotypes and perturbation/rescue. Independently test interlineage competition and serial mature/barrier function; a fitness sign reversal alone neither validates any native candidate nor predicts older-human cancer prevention. In the same older-donor epithelial model compare retained versus removed residents with matched initial wounding and adequate functional replacement, and separately vary immune presence when feasible. Track resident–invader contacts, direct losses, basal extrusion, matrix and mature function. Resident protection is supported only as a measured contribution after removal-induced injury alternatives are tested; immune-free behavior alone does not establish in-vivo immunity irrelevance. Compare genotype-resolved survival and fate under recorded inflammatory exposure versus comparable noninflamed conditions, with functional perturbation/rescue and serial mature/barrier outcomes. Prospectively track cancer outcomes separately. Any colitis-context resistance prediction does not imply an age-only benefit or make a resident universally protective. Factorially vary defined matrix chemistry/architecture and selective signaling perturbation/rescue within a recorded genotype and matched repair context; measure actual crosslinks, focal signaling, basement-membrane crossing, mutation acquisition and wound strength separately. A matrix contribution can coexist with all four native mechanisms and does not establish absence of new mutations merely because none were intended. Compare retention, suppression and the specified removal procedure using delivered toxin activity/contact, functional barrier measures and surviving-renewal-cell damage. Proceed to the lesion-mediated prediction only if that first link is supported in the proposed model; absence under rapid functional replacement bounds that procedure, not all epithelial removal. Preserve banked ancestral lines, baseline detection bounds, time-resolved ancestry and post-exposure lesion timing. Test nominated new changes in the relevant ancestral/descendant genetic background, with existing drivers characterized, and require a causal contribution to sustained anatomical invasion after washout in a justified common niche rather than signature enrichment or toxin dependence alone. Across independent ancestral replicates compare exposure-linked rates and distributions of surviving causal-lesion descendants, with uncertainty, delivered dose, cell loss/arrest and adequate follow-up recorded. Restoration means recovery of the conditional distributional contribution within a justified exposure regime; a finite unmatched stochastic realization is not falsification, and no universal monotonic dose response is asserted. Report both total-effect and pulse-clamped estimates with their distinct intervention conditions; track all initial lineages, death and surviving descendants, then report survivor-conditional quantities as such. Preserve the toxin-to-death-to-feeding chain in total-effect comparisons and use ancestral matching rather than treating survivor selection as randomization. Where indicated, test justified lesion sets and characterized cooperating state/background with matched genetic controls. Retain the exposure-to-ancestry chain and test sustained basement-membrane crossing in a shared niche justified for the original tissue. Invasion enabled only by an artificial permissive matrix does not establish consequential invasion caused by removal in aging tissue. Current finding-specific qualification: Toxin restoration remains a conditional distributional prediction, with distinct estimands per initial lineage, per exposure and conditional on survival. A pulse-clamped contrast is a separate controlled effect only if the clamp is feasible and does not independently alter delivered toxin, susceptibility or relevant repair functions; feasibility is not established. Prespecify follow-up and report the probability of at least one causal-lesion descendant per starting lineage, absolute causal-lesion descendant counts per initial lineage, and any exposure-normalized rate with its exposure denominator and uncertainty; separately label survivor-conditional quantities and follow all initial lineages including deaths/arrests. Validate any pulse clamp for exposure and susceptibility; if validation fails, omit its isolated causal interpretation while retaining the total-effect arm with toxin-induced injury, death and feeding intact. Validate producer deletion/complementation ecology and delivery; toxin dependence alone still does not distinguish new-lesion causality from selection.

Which of the figures above have a study behind them, which are the engine's own, and what it would take to refute the hypothesis. This audit never judges the idea.