LR-DRAFT-BIO-12 · Biology
OPENBacterial flagellar motor rotation
A scoped, source-linked candidate record for bacterial flagellar motor rotation.
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Limits RegistryRegistry collection
Unsolved Limits in Biology
Open biological frontiers spanning genomes, cells, organisms, evolution, and living systems.
48 published records in this collectionLR-DRAFT-BIO-08 · Biology
OPENBacterial ribosome translation rate
A scoped, source-linked candidate record for bacterial ribosome translation rate.
LR-DRAFT-BIO-04 · Biology
OPENBacteriorhodopsin quantum yield
A scoped, source-linked candidate record for bacteriorhodopsin quantum yield.
LR-BLUE-WHALE-MASS · Biology
OPENBlue whale — heaviest recorded animal
A female blue whale caught in the Southern Ocean on March 20, 1947 was recorded at 190 tonnes (418,878 lb) and 27.6 meters long — the heaviest individual animal ever confirmed. Blue whales remain the most massive animals known to have lived, though several other species exceed them in body length alone.
LR-DRAFT-BIO-20 · Biology
OPENBlue-whale heart mass
A scoped, source-linked candidate record for blue-whale heart mass.
LR-DRAFT-C3 · Biology
OPENC3 photosynthetic efficiency
Photosynthesis converts sunlight into chemical energy, but real-world efficiency falls far short of the theoretical maximum due to biochemical and physical losses. This record cites the observed efficiency ceiling for C3 plants — the majority of crop species — under a specific modeled canopy scenario.
LR-DRAFT-BIO-03 · Biology
OPENCarbonic-anhydrase catalytic turnover
A scoped, source-linked candidate record for carbonic-anhydrase catalytic turnover.
LR-DRAFT-BIO-18 · Biology
OPENCheetah sprint speed
A scoped, source-linked candidate record for cheetah sprint speed.
LR-DRAFT-BIO-14 · Biology
OPENDNA polymerase processivity
A scoped, source-linked candidate record for dna polymerase processivity.
LR-004209 · Biology
OPENDiffusion-limited enzyme catalytic efficiency
The upper kinetic regime for enzyme catalytic efficiency is commonly placed near 10⁸–10⁹ M⁻¹ s⁻¹.
LR-004207 · Biology
OPENFast protein-folding timescale
Small single-domain proteins can fold on microsecond timescales, with engineered ultrafast folders reported near 4 μs.
LR-DRAFT-BIO-02 · Biology
OPENFastest Escherichia coli doubling
A scoped, source-linked candidate record for fastest escherichia coli doubling.
LR-DRAFT-BIO-11 · Biology
OPENFastest known enzyme turnover
A scoped, source-linked candidate record for fastest known enzyme turnover.
LR-DRAFT-HAYFLICK · Biology
OPENHistorical Hayflick fibroblast record
Normal human cells don't divide forever — the Hayflick limit is the historical observation that established cellular senescence as a real biological phenomenon, not the discovery of a single universal number.
LR-DRAFT-BIO-24 · Biology
OPENHuman cortical neuron count
A scoped, source-linked candidate record for human cortical neuron count.
LR-DRAFT-BIO-06 · Biology
OPENHuman mitochondrial genome size
A scoped, source-linked candidate record for human mitochondrial genome size.
LR-DRAFT-BIO-16 · Biology
OPENHuman red-blood-cell lifespan
A scoped, source-linked candidate record for human red-blood-cell lifespan.
LR-DRAFT-BIO-17 · Biology
OPENHuman sperm swimming speed
A scoped, source-linked candidate record for human sperm swimming speed.
LR-DRAFT-BIO-05 · Biology
OPENHuman telomere shortening rate
A scoped, source-linked candidate record for human telomere shortening rate.
LR-DRAFT-BIO-27 · Biology
OPENHummingbird wingbeat frequency
A scoped, source-linked candidate record for hummingbird wingbeat frequency.
LR-DRAFT-BIO-21 · Biology
OPENLargest bacterial cell diameter
A scoped, source-linked candidate record for largest bacterial cell diameter.
LR-004208 · Biology
OPENLargest estimated wild animal population biomass
Antarctic krill surveys have estimated hundreds of millions of tonnes of standing biomass across the Southern Ocean.
LR-004205 · Biology
OPENLargest known haploid genome
The flowering plant Paris japonica has a reported haploid genome size of approximately 149 billion base pairs.
LR-DRAFT-BIO-29 · Biology
OPENLargest known viral genome
A scoped, source-linked candidate record for largest known viral genome.
LR-DRAFT-BIO-23 · Biology
OPENLongest known animal lifespan
A scoped, source-linked candidate record for longest known animal lifespan.
LR-DRAFT-BIO-25 · Biology
OPENMammalian gestation length
A scoped, source-linked candidate record for mammalian gestation length.
LR-DRAFT-BIO-07 · Biology
OPENMaximum antibody affinity
A scoped, source-linked candidate record for maximum antibody affinity.
LR-DRAFT-BIO-30 · Biology
OPENMaximum bacterial growth rate model
A scoped, source-linked candidate record for maximum bacterial growth rate model.
LR-DRAFT-BIO-26 · Biology
OPENMaximum mammalian diving depth
A scoped, source-linked candidate record for maximum mammalian diving depth.
LR-100M-MEN · Biology
OPENMen's 100 meters sprint
Usain Bolt ran 9.58 seconds at the 2009 World Championships in Berlin on August 16, 2009, breaking his own previous world record of 9.69 seconds set a year earlier. It remains the official World Athletics record as of 2026.
LR-HIGH-JUMP-MEN · Biology
OPENMen's high jump
Cuba's Javier Sotomayor cleared 2.45 meters on July 27, 1993 in Salamanca, Spain. It is the longest-standing record in men's track and field still on the books, unbroken as of 2026.
LR-LONG-JUMP-MEN · Biology
OPENMen's long jump
The United States' Mike Powell jumped 8.95 meters on August 30, 1991 at the World Championships in Tokyo, breaking Bob Beamon's 23-year-old record of 8.90 m. It remains unbroken as of 2026.
LR-MARATHON-MEN · Biology
OPENMen's marathon
Kenya's Sabastian Sawe ran 1:59:30 at the 2026 London Marathon on April 26, 2026 — the first sub-two-hour marathon ever run in official, record-eligible race conditions. (Eliud Kipchoge's 1:59:40 in the 2019 INEOS 1:59 Challenge used rotating pacers and a start/finish loop that made it ineligible as an official record.)
LR-DRAFT-BIO-10 · Biology
OPENMinimal gene set for bacterial growth
A scoped, source-linked candidate record for minimal gene set for bacterial growth.
LR-004206 · Biology
OPENMinimum bacterial doubling time under laboratory conditions
Escherichia coli can approach a 20-minute doubling time in optimized rich-medium laboratory cultures.
LR-DRAFT-BIO-19 · Biology
OPENPeregrine falcon dive speed
A scoped, source-linked candidate record for peregrine falcon dive speed.
LR-PEREGRINE-FALCON-DIVE · Biology
OPENPeregrine falcon dive speed
Falconer Ken Franklin's trained peregrine falcon, Frightful, was recorded diving at 242 mph (389.5 km/h) in 1999 after being released from a Cessna 172 at 17,000 feet and tracked with an altimeter and GPS. Guinness World Records recognizes it as the fastest confirmed speed of any animal on Earth.
LR-DRAFT-BIO-09 · Biology
OPENPhotosystem II quantum efficiency
A scoped, source-linked candidate record for photosystem ii quantum efficiency.
LR-XPRIZE-HEALTHSPAN · Biology
OPENReversal of age-related functional decline
XPRIZE Healthspan is a $101M competition (launched 2023, running through 2030) challenging teams to develop a real therapeutic — not just a way to slow aging, but to measurably reverse already-occurred functional decline. As of August 2026, 20 finalist teams are in clinical trials; 10 received $1M Milestone 2 awards, but no grand prize has been claimed.
LR-DRAFT-BIO-13 · Biology
OPENRibosome peptide-bond formation rate
A scoped, source-linked candidate record for ribosome peptide-bond formation rate.
LR-DRAFT-GENOME · Biology
OPENSmallest demonstrated autonomously growing bacterial cell
How few genes does a living cell need to independently grow and divide? The JCVI-syn3.0 synthetic bacterium demonstrates the smallest genome shown to support autonomous life in a laboratory setting — not a claim about the theoretical minimum for life itself.
LR-DRAFT-BIO-22 · Biology
OPENSmallest flowering plant genome
A scoped, source-linked candidate record for smallest flowering plant genome.
LR-DRAFT-BIO-01 · Biology
OPENSmallest free-living bacterial genome
A scoped, source-linked candidate record for smallest free-living bacterial genome.
LR-DRAFT-BIO-15 · Biology
OPENT4 bacteriophage genome packing density
A scoped, source-linked candidate record for t4 bacteriophage genome packing density.
LR-DRAFT-BIO-28 · Biology
OPENTardigrade desiccation survival
A scoped, source-linked candidate record for tardigrade desiccation survival.
LR-100M-WOMEN · Biology
OPENWomen's 100 meters sprint
Florence Griffith-Joyner ran 10.49 seconds at the 1988 U.S. Olympic Trials in Indianapolis on July 16, 1988, with an official wind reading of 0.0 m/s. World Athletics still recognizes it as the official record as of 2026, though Track & Field News and some biomechanists have long argued the wind gauge reading understated an assisting wind. The record has never been annulled.
LR-MARATHON-WOMEN-MIXED · Biology
OPENWomen's marathon (mixed-sex race)
Kenya's Ruth Chepngetich ran 2:09:56 at the 2024 Chicago Marathon on October 13, 2024, the first woman to break 2:10 in a mixed-sex race. World Athletics confirmed the time as the official mixed-sex world record.
LR-MARATHON-WOMEN-ONLY · Biology
OPENWomen's marathon (women-only race)
Ethiopia's Tigst Assefa ran 2:15:41 at the 2026 London Marathon on April 26, 2026 — the fastest marathon ever run by a woman with no male pacers. World Athletics tracks this as a separate category from the mixed-sex record because male pacers measurably improve women's race times.