The DOI matches its Crossref record; 62 of the 63 references it cites were found in a registry or an index.
Establishing the validity of domestication genes using DNA from ancient chickens
Open accessAbstract
Significance: Recent studies have identified the genetic basis of numerous traits that differentiate modern domestic species from their wild counterparts. In both plants and animals, traits (and the genes underlying them) found ubiquitously in modern breeds are often presumed to have been selected early during the domestication process. Here, by determining genetic variability in ancient European chickens over the past 2,000 years, we show that a mutation thought to be crucial during chicken domestication was not subjected to strong human-mediated selection until much later in time. This result demonstrates that the ubiquity of mutations, which differentiate modern wild and domestic taxa, does not necessarily imply ancient origins.
Overview
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Integrity signals
Registry
Cites
Statistics
Verification
Claims the paper makes
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
The source backs part of the claim, not all of it — or backs it for a different population, condition or comparison.
In the citing paper
“Additionally, chicken bones are prone to taphonomic loss through scavenger activity (11) and stratigraphic displacement (12).”
From The biocultural origins and dispersal of domestic chickens (2022) · cites this paper as [12]
Experimental — accuracy not yet measuredThe source backs part of the claim, not all of it — or backs it for a different population, condition or comparison.
In the citing paper
“For example, an ancient DNA study shows how two strong sweeps in the domestic chicken, at TSHR and BCO2, both were selected much later than early domestication (Flink et al. 2014; Loog et al. 2017).”
From The neural crest cell hypothesis: no unified explanation for domestication (2021) · cites this paper as Flink et al. 2014
Experimental — accuracy not yet measuredThe check wasn’t confident either way, so it gives no verdict — never disputed.
In the citing paper
“Although isolated chicken remains have been claimed on Bronze Age settlements, radiocarbon dating has revealed that specimens excavated at Korucutepe, Turkey (12) and Jerusalem, Israel were intrusive (SI Appendix, Table S3).”
From The biocultural origins and dispersal of domestic chickens (2022) · cites this paper as [12]
Experimental — accuracy not yet measuredIn the citing paper
“This genetic marker could be used to recognize Gallus gallus domesticus in the future fossil record, in the way that the β-carotene dioxygenase 2 gene associated with yellow skin colour resulting from a diet of maize may be identified in archaeological chicken bones from approximately 500 years ago [60].”
From The broiler chicken as a signal of a human reconfigured biosphere (2018) · cites this paper as [60]
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
The self-check needs the paper’s full text.
Citations
Cites
Guindon, S., Dufayard, J.-F., Lefort, V., Anisimova, M., Hordijk, W., & Gascuel, O. (2010) · Systematic Biology · doi:10.1093/sysbio/syq010 · Cited by 18,376
MAFFT: a novel method for rapid multiple sequence alignment based on fast Fourier transform
Katoh, K. (2002) · Nucleic Acids Research · doi:10.1093/nar/gkf436 · Cited by 17,027
MrModeltest 2.2. Program Distributed by the Author
Nylander, J. A. A., Nylander, J., & Nylander, J. A. A. (2004) · Medical Entomology and Zoology · Cited by 2,648
Double muscling in cattle due to mutations in the myostatin gene
McPherron, A. C., & Lee, S.-J. (1997) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.94.23.12457 · Cited by 2,039
A NAC Gene Regulating Senescence Improves Grain Protein, Zinc, and Iron Content in Wheat
Uauy, C., Distelfeld, A., Fahima, T., Blechl, A. E., & Dubcovsky, J. (2006) · Science · doi:10.1126/science.1133649 · Cited by 1,607
Ancient DNA: Do It Right or Not at All
Cooper, A., & Poinar, H. N. (2000) · Science · doi:10.1126/science.289.5482.1139b · Cited by 1,291
Whole-genome resequencing reveals loci under selection during chicken domestication
Rubin, C.-J., Zody, M. C., Eriksson, J., Meadows, J. R. S., Sherwood, E., Webster, M. T., Jiang, L., Ingman, M., Sharpe, T., Ka, S., et al. (2010) · Nature · doi:10.1038/nature08832 · Cited by 1,138
Self-citationThe genomic signature of dog domestication reveals adaptation to a starch-rich diet
Axelsson, E., Ratnakumar, A., Arendt, M.-L., Maqbool, K., Webster, M. T., Perloski, M., Liberg, O., Arnemo, J. M., Hedhammar, Å., & Lindblad-Toh, K. (2013) · Nature · doi:10.1038/nature11837 · Cited by 963
A regulatory mutation in IGF2 causes a major QTL effect on muscle growth in the pig
Laere, A.-S. V., Nguyen, M. Q., Braunschweig, M., Nezer, C., Collette, C., Moreau, L., Archibald, A. L., Haley, C., Buys, N., Tally, M., et al. (2003) · Nature · doi:10.1038/nature02064 · Cited by 949
Self-citationThe Earliest Horse Harnessing and Milking
Outram, A. K., Stear, N. A., Bendrey, R., Olsen, S. L., Kasparov, A., Zaibert, V. F., Thorpe, N., & Evershed, R. P. (2009) · Science · doi:10.1126/science.1168594 · Cited by 794
Hofreiter, M. (2001) · Nucleic Acids Research · doi:10.1093/nar/29.23.4793 · Cited by 684
Rise and Fall of the Beringian Steppe Bison
Shapiro, B., Drummond, A. J., Rambaut, A., Wilson, M. C., Matheus, P. E., Sher, A. V., Pybus, O. G., Gilbert, M. T. P., Barnes, I., Binladen, J., et al. (2004) · Science · doi:10.1126/science.1101074 · Cited by 675
A Single IGF1 Allele Is a Major Determinant of Small Size in Dogs
Sutter, N. B., Bustamante, C. D., Chase, K., GRAY, M. M., Zhao, K., Zhu, L., Padhukasahasram, B., Karlins, E., Davis, S. R., Jones, P. G., et al. (2007) · Science · doi:10.1126/science.1137045 · Cited by 673
Radiocarbon and DNA evidence for a pre-Columbian introduction of Polynesian chickens to Chile
Storey, A. A., Ramírez, J. M., Quiroz, D., Burley, D. V., Addison, D. J., Walter, R., Anderson, A. J., Hunt, T. L., Athens, J. S., Huynen, L., et al. (2007) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.0703993104 · Cited by 645
Gilbert, M. T. P., Bandelt, H.-J., Hofreiter, M., & Barnes, I. (2005) · Trends in Ecology & Evolution · doi:10.1016/j.tree.2005.07.005 · Cited by 602
Rethinking Dog Domestication by Integrating Genetics, Archeology, and Biogeography
Larson, G., Karlsson, E. K., Perri, A., Webster, M. T., Ho, S. Y. W., Peters, J., Stahl, P. W., Piper, P. J., Lingaas, F., Fredholm, M., et al. (2012) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.1203005109 · Cited by 540
Self-citationKiefer, C., Hessel, S., Lampert, J. M., Vogt, K., Lederer, M. O., Breithaupt, D. E., & Lintig, J. V. (2001) · Journal of Biological Chemistry · doi:10.1074/jbc.m011510200 · Cited by 453
Multiple maternal origins of chickens: Out of the Asian jungles
Liu, Y.-P., Wu, G.-S., Yao, Y.-G., Miao, Y.-W., Luikart, G., Baig, M., Beja-Pereira, A., Ding, Z.-L., Palanichamy, M. G., & Zhang, Y.-P. (2006) · Molecular Phylogenetics and Evolution · doi:10.1016/j.ympev.2005.09.014 · Cited by 444
Mutations in DMRT3 affect locomotion in horses and spinal circuit function in mice
Andersson, L. S., Larhammar, M., Memic, F., Wootz, H., Schwochow, D., Rubin, C., Patra, K., Árnason, T., Wellbring, L., Hjälm, G., et al. (2012) · Nature · doi:10.1038/nature11399 · Cited by 431
Self-citationIdentification of the Yellow Skin Gene Reveals a Hybrid Origin of the Domestic Chicken
Eriksson, J., Larson, G., Gunnarsson, U., Bed'hom, B., Tixier-Boichard, M., Strömstedt, L., Wright, D., Jungerius, A., Vereijken, A., Randi, E., et al. (2008) · PLoS Genetics · doi:10.1371/journal.pgen.1000010 · Cited by 426
Self-citationA Bountiful Harvest: Genomic Insights into Crop Domestication Phenotypes
Olsen, K. M., & Wendel, J. F. (2013) · Annual Review of Plant Biology · doi:10.1146/annurev-arplant-050312-120048 · Cited by 403
Dynamics of Pleistocene Population Extinctions in Beringian Brown Bears
Barnes, I., Matheus, P. E., Shapiro, B., Jensen, D., & Cooper, A. (2002) · Science · doi:10.1126/science.1067814 · Cited by 400
Gagneux, P., Boesch, C., & Woodruff, D. S. (1997) · Molecular Ecology · doi:10.1111/j.1365-294x.1997.tb00140.x · Cited by 386
An Expressed Fgf4 Retrogene Is Associated with Breed-Defining Chondrodysplasia in Domestic Dogs
Parker, H. G., VonHoldt, B. M., Quignon, P., Margulies, E. H., Shao, S., Mosher, D. S., Spady, T. C., Elkahloun, A., Cargill, M., Jones, P. G., et al. (2009) · Science · doi:10.1126/science.1173275 · Cited by 342
Pielberg, G., Golovko, A., Sundström, E., Čurik, I., Lennartsson, J., Seltenhammer, M. H., Druml, T., Binns, M. M., Fitzsimmons, C., Lindgren, G., et al. (2008) · Nature Genetics · doi:10.1038/ng.185 · Cited by 335
Self-citationEarly Allelic Selection in Maize as Revealed by Ancient DNA
Jaenicke-Després, V., Buckler, E. S., Smith, B. D., Gilbert, M. T. P., Cooper, A., Doebley, J., & Pääbo, S. (2003) · Science · doi:10.1126/science.1089056 · Cited by 324
Coat Color Variation at the Beginning of Horse Domestication
Ludwig, A., Pruvost, M., Reißmann, M., Benecke, N., Brockmann, G. A., Castaños, P., Cieslak, M., Lippold, S., Rodríguez, L. L., Malaspinas, A., et al. (2009) · Science · doi:10.1126/science.1172750 · Cited by 309
Chicken domestication: an updated perspective based on mitochondrial genomes
Miao, Y.-W., Peng, M.-S., Wu, G.-S., Ouyang, Y.-N., Yang, Z.-Y., Yu, N., Liang, J.-P., PianChou, G., Beja‐Pereira, A., Mitra, B., et al. (2012) · Heredity · doi:10.1038/hdy.2012.83 · Cited by 274
Contrasting Mode of Evolution at a Coat Color Locus in Wild and Domestic Pigs
Fang, M., Larson, G., Ribeiro, H., Li, N., & Andersson, L. (2009) · PLoS Genetics · doi:10.1371/journal.pgen.1000341 · Cited by 271
Self-citationOttoni, C., Girdland-Flink, L., Evin, A., Geörg, C., Cupere, B. D., Neer, W. V., Bartosiewicz, L., Linderholm, A. E., Barnett, R., Peters, J., et al. (2012) · Molecular Biology and Evolution · doi:10.1093/molbev/mss261 · Cited by 259
Self-citationCopy Number Variation in Intron 1 of SOX5 Causes the Pea-comb Phenotype in Chickens
Wright, D., Boije, H., Meadows, J. R. S., Bed’Hom, B., Gourichon, D., Vieaud, A., Tixier‐Boichard, M., Rubin, C., Imsland, F., Hallböök, F., et al. (2009) · PLoS Genetics · doi:10.1371/journal.pgen.1000512 · Cited by 257
Self-citationDid chickens go North? New evidence for domestication
West, B., & Zhou, B.-X. (1988) · Journal of Archaeological Science · doi:10.1016/0305-4403(88)90080-5 · Cited by 221
Hillbertz, N. S., Isaksson, M., Karlsson, E. K., Hellmén, E., Pielberg, G., Savolainen, P., Wade, C. M., von Euler, H., Gustafson, U., Hedhammar, Å. A., et al. (2007) · Nature Genetics · doi:10.1038/ng.2007.4 · Cited by 220
Self-citationRecharacterization of ancient DNA miscoding lesions: insights in the era of sequencing-by-synthesis
Gilbert, M. T. P., Binladen, J., Miller, W., Wiuf, C., Willerslev, E., Poinar, H. N., Carlson, J. E., Leebens‐Mack, J., & Schuster, S. C. (2006) · Nucleic Acids Research · doi:10.1093/nar/gkl483 · Cited by 212
Cultural atlas of Mesopotamia and the ancient near East
Roaf, M. (1990) · Medical Entomology and Zoology · Cited by 181
Olsson, M., Meadows, J. R. S., Truvé, K., Pielberg, G., Puppo, F., Mauceli, E., Quilez, J., Tonomura, N., Zanna, G., Docampo, M. J., et al. (2011) · PLoS Genetics · doi:10.1371/journal.pgen.1001332 · Cited by 168
Self-citationA Mutation in Hairless Dogs Implicates FOXI3 in Ectodermal Development
Drögemüller, C., Karlsson, E. K., Hytönen, M. K., Perloski, M., Dolf, G., Sainio, K., Lohi, H., Lindblad‐Toh, K., & Leeb, T. (2008) · Science · doi:10.1126/science.1162525 · Cited by 151
Storey, A. A., Athens, J. S., Bryant, D., Carson, M., Emery, K., deFrance, S., Higham, C., Huynen, L., Intoh, M., Jones, S., et al. (2012) · PLoS ONE · doi:10.1371/journal.pone.0039171 · Cited by 137
Evolutionary genomics of dog domestication
Wayne, R. K., & vonHoldt, B. M. (2012) · Mammalian Genome · doi:10.1007/s00335-011-9386-7 · Cited by 127
Localization of Canine Brachycephaly Using an Across Breed Mapping Approach
Bannasch, D. L., Young, A. E., Myers, J. A., Truvé, K., Dickinson, P. J., Gregg, J. P., Davis, R. R., Bongcam‐Rudloff, E., Webster, M. T., Lindblad‐Toh, K., et al. (2010) · PLoS ONE · doi:10.1371/journal.pone.0009632 · Cited by 120
Indo-European and Asian origins for Chilean and Pacific chickens revealed by mtDNA
Gongora, J., Rawlence, N. J., Mobegi, V. A., Jianlin, H., Alcalde, J. A., Matus, J. T., Hanotte, O., Moran, C., Austin, J. J., Ulm, S., et al. (2008) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.0801991105 · Cited by 117
Self-citationBenecke, N. (1994) · De Gruyter eBooks · doi:10.1515/9783050069456 · Cited by 95
Tracing genetic change over time using nuclear SNPs in ancient and modern cattle
Svensson, E., Anderung, C., Baubliene, J., Persson, P., Malmström, H., Smith, C. I., Vretemark, M., Daugnora, L., & Götherström, A. (2007) · Animal Genetics · doi:10.1111/j.1365-2052.2007.01620.x · Cited by 87
Self-citationHow selective sweeps in domestic animals provide new insight into biological mechanisms
Andersson, L. (2011) · Journal of Internal Medicine · doi:10.1111/j.1365-2796.2011.02450.x · Cited by 74
Self-citationThe IGF1small dog haplotype is derived from Middle Eastern grey wolves
GRAY, M. M., Sutter, N. B., Ostrander, E. A., & Wayne, R. K. (2010) · BMC Biology · doi:10.1186/1741-7007-8-16 · Cited by 74
Mitochondrial DNA from 3000-year old chickens at the Teouma site, Vanuatu
Storey, A. A., Spriggs, M., Bedford, S., Hawkins, S., Robins, J., Huynen, L., & Matisoo-Smith, E. A. (2010) · Journal of Archaeological Science · doi:10.1016/j.jas.2010.05.006 · Cited by 58
Molecular consequences of animal breeding
Andersson, L. (2013) · Current Opinion in Genetics & Development · doi:10.1016/j.gde.2013.02.014 · Cited by 57
Self-citationPeters, J. (1998) · Medical Entomology and Zoology · Cited by 52
Self-citationDana, N., Megens, H., Crooijmans, R. P. M. A., Hanotte, O., Mwacharo, J. M., Groenen, M. A. M., & van Arendonk, J. A. M. (2010) · Animal Genetics · doi:10.1111/j.1365-2052.2010.02134.x · Cited by 43
Die Tierwelt des alten Ägypten
Boessneck, J. (1988) · Beck eBooks · Cited by 42
Re-evaluating the history of the wheat domestication gene NAM-B1 using historical plant material
Asplund, L., Hagenblad, J., & Leino, M. W. (2010) · Journal of Archaeological Science · doi:10.1016/j.jas.2010.04.003 · Cited by 40
Prummel, W. (1997) · University of Groningen research database (University of Groningen / Centre for Information Technology) · Cited by 39
Origin of Hungarian indigenous chicken breeds inferred from mitochondrial DNA D‐loop sequences
Révay, T., Pálinkás‐Bodzsár, N., Mobegi, V. E., Hanotte, O., & Hidas, A. (2010) · Animal Genetics · doi:10.1111/j.1365-2052.2010.02041.x · Cited by 32
Barking up the wrong tree: Modern northern European dogs fail to explain their origin
Malmström, H., Vilà, C., Gilbert, M. T. P., Storå, J., Willerslev, E., Holmlund, G., & Götherström, A. (2008) · BMC Evolutionary Biology · doi:10.1186/1471-2148-8-71 · Cited by 31
Self-citationSelkirk Rex: Morphological and Genetic Characterization of a New Cat Breed
Filler, S., Alhaddad, H., Gandolfi, B., Kurushima, J. D., Cortés, A., Veit, C., Lyons, L. A., & Brem, G. (2012) · Journal of Heredity · doi:10.1093/jhered/ess039 · Cited by 26
Some comments on the introduction of domestic fowl in Iberia
Carrasquilla, F. H. (1992) · Archaeofauna · doi:10.15366/archaeofauna1992.1.005 · Cited by 22
Braemer, F. (1993) · Périodiques Scientifiques en Édition Électronique · Cited by 17
Römische Tierhaltung und Tierzucht
Peters, J. (1998) · Leidorf eBooks · Cited by 16
Self-citationReexamination of the domestic chicken in ancient China
Deng, H., Yuan, J., Song, G., Wang, C., & Eda, M. (2014) · Chinese Archaeology · doi:10.1515/char-2014-0021 · Cited by 12
Tegetmeier, W. B., & Weir, H. (1867) · doi:10.5962/bhl.title.131278 · Cited by 4
Carrott, J., Hughes, P. D. M., Jaques, D., Johnstone, C., Kenward, H. K., & Worthy, D. (1998) · Cited by 2
Der Lorenzberg bei Epfach : die Spätrömischen und frühmittelalterlichen Anlagen
Werner, J., Dannheimer, H., Kellner, H.-J., & Pohl, G. (1969) · C.H.Beck eBooks · Cited by 2
Flagged first, then by citations
1 of the 63 references couldn’t be matched to a known paper.
Research works printed but not linked: 4
- BS Chow, The animal remains discovered at Cishan village, Wu’an, Hebei Province. Kaogu Xuebao 62, 339–348, Chinese. (1981).
- BS Chow, The animal remains discovered at Baiyingsite, Tangyin, Henan Province. Papers on Chinese Archaeology 3, 48–50, Chinese. (1983).
- PJK McGowan, Phasianidae (Pheasants and Partridges). Handbook of the Birds of the World, eds J del Hoyo, A Elliott, J Sargatal (Lynx Edicions, Barcelona, Spain), pp. 434–552 (1994).
- U Aldrovandi Ornithologiae Tomus Alter cum Indice Copiosissimo Variarum Linguarum (Giovanni Battista Bellagamba, Bologna, 1600).
Cited by
Sorted by citations
Current perspectives and the future of domestication studies
Larson, G., Piperno, D. R., Allaby, R. G., Purugganan, M. D., Andersson, L., Arroyo‐Kalin, M., Barton, L., Vigueira, C. C., Denham, T. P., Dobney, K. M., et al. (2014) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.1323964111 · Cited by 868
Self-citationThe Evolution of Animal Domestication
Larson, G., & Fuller, D. Q. (2014) · Annual Review of Ecology, Evolution, and Systematics · doi:10.1146/annurev-ecolsys-110512-135813 · Cited by 640
Self-citationCore questions in domestication research
Zeder, M. A. (2015) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.1501711112 · Cited by 584
Orlando, L., Allaby, R., Skoglund, P., Der Sarkissian, C., Stockhammer, P. W., Ávila-Arcos, M. C., Fu, Q., Krause, J., Willerslev, E., Stone, A. C., et al. (2021) · Nature Reviews Methods Primers · doi:10.1038/s43586-020-00011-0 · Cited by 411
Frantz, L., Schraiber, J. G., Madsen, O., Megens, H., Cagan, A., Bosse, M., Paudel, Y., Crooijmans, R. P. M. A., Larson, G., & Groenen, M. A. M. (2015) · Nature Genetics · doi:10.1038/ng.3394 · Cited by 342
Self-citation
Metadata
- Authors
- Girdland Flink, L., Allen, R., Barnett, R., Malmström, H., Peters, J., Eriksson, J., Andersson, L., Dobney, K., & Larson, G.
- Affiliations
- Durham Evolution and Ancient DNA, Department of Archaeology,
- Durham University (GB)
- Uppsala University (SE)
- Ludwig-Maximilians-Universität München (DE)
- University of Aberdeen (GB)
- ORCID
- Venue
- Proceedings of the National Academy of Sciences
- Publisher
- National Academy of Sciences
- Published
- 2014-04-21
- Volume
- 111
- Issue
- 17
- Pages
- 6184-6189
- ISSN
- 0027-8424 (ISSN-L)
- 1091-6490
- PMC
- PMC4035994
- OpenAlex
- W2161811970
- Cited by
- 107
- References
- 63
- Citations by year
- 2026: 2 · 2025: 2 · 2024: 9 · 2022: 4 · 2021: 10 · 2020: 9 · 2019: 9 · 2018: 11 · 2017: 10 · 2016: 14 · 2015: 15 · 2014: 11
- FWCI
- 10.95
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Locations
- Proceedings of the National Academy of Sciences (publishedVersion)
- Europe PMC (PubMed Central) (publishedVersion)
- PubMed Central (publishedVersion)
- PubMed (publishedVersion)
- Aberdeen University Research Archive (Aberdeen University) (submittedVersion)
- Funders
- National Science Foundation (0905606)
- National Evolutionary Synthesis Center (EF0905606, 0905606)
- Leverhulme Trust
- Research Councils UK
- Natural Environment Research Council (NE/F003382/2, NE/F003382/1, NE/K005243/2, NE/K003259/1, NE/K005243/1, NE/H005552/1, NE/H005269/1)
- Topics
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Genetics › Forensic and Genetic Research
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Genetics › Genetic and phenotypic traits in livestock
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Genetics › Genetic diversity and population structure
- Keywords
- chicken domestication, domestication genes, ancient DNA, selection signatures, thyroid-stimulating hormone receptor, mitochondrial DNA control region, admixture
- MeSH terms
- Animals, Animals, Domestic, Chickens, DNA, DNA, Mitochondrial, Europe, Geography, Haplotypes, Humans, Molecular Sequence Data, Reproducibility of Results, History, Ancient
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
