Generation Time

Generation time is the τ-categorical period of the carrier-lineage's reproduction loop on τ¹: the average time between corresponding events in successive generations of a finite-lineage carrier. It is the temporal step of the PPAS prover (natural selection) on the fitness landscape, and the unit in which polynomial-time evolutionary convergence is counted.

Categorical invariant. Period T_gen of the lineage-level α-winding (lift of the cell cycle to the multicellular consumer carrier), and the discrete time-step of the PPAS verification round on the fitness landscape (VI.D50, VI.T27).

Primary registry anchor: VI.D50

Supporting items: VI.T27, VI.D48, VI.D25

1. I.K0 — Universe Postulate
2. VI.D15 — Life Sector
3. VI.D25 — Temporal Stability Predicate
4. VI.D48 — Multicellularity as Colimit — multicellular reproduction unit
5. VI.D50 — PPAS Algorithm on Fitness Landscapes — generation = verification round
6. VI.T27 — Evolution as Polynomial-Time PPAS — convergence in O(generation time)

Biomarker: Time from birth to median first reproduction across taxa; molecular-clock substitution rate per generation; demographic generation time T = ∑ x · l(x) · m(x) / ∑ l(x) · m(x) (Lotka equation), where l(x) is survivorship and m(x) is age-specific fecundity.

Measurable range: E. coli T_gen ≈ 20 min (optimal); yeast T_gen ≈ 90 min; Drosophila T_gen ≈ 2 weeks; mouse T_gen ≈ 10 weeks; human T_gen ≈ 25–30 yr; tortoise/whale T_gen ≈ 20–30 yr; lifetime offspring count covaries inversely (r/K life-history axis).

Observation method: Demographic life-table analysis, microbial doubling-time assays, longitudinal pedigree records, molecular-clock calibration against fossil record, age-structured population modelling.

Calibration anchor: LG-Y02-kinetic-pseudoscalar-channel

Anchor chain:

1. VI.L18 chirality channel
2. stereospecificity of replicative DNA-polymerase active sites that bound minimum cycle time
3. homochirality of the genome copied each generation

Manuscript reference: manuscript-sources/book-06/part06/ch37-evolution-ppas.tex

Status: Planned

Related glossary entries

• LG-T02-cell-cycle Cell Cycle
• LG-T04-aging-trajectory Aging Trajectory
• LG-Y02-kinetic-pseudoscalar-channel Kinetic Pseudoscalar Channel