https://w3id.org/np/RAoI9yt_Ry2q2YaVjoCFBd96MDy1QxyRDKWZ073mHKRss/Head https://w3id.org/np/RAoI9yt_Ry2q2YaVjoCFBd96MDy1QxyRDKWZ073mHKRss http://www.nanopub.org/nschema#hasAssertion https://w3id.org/np/RAoI9yt_Ry2q2YaVjoCFBd96MDy1QxyRDKWZ073mHKRss/assertion https://w3id.org/np/RAoI9yt_Ry2q2YaVjoCFBd96MDy1QxyRDKWZ073mHKRss http://www.nanopub.org/nschema#hasProvenance https://w3id.org/np/RAoI9yt_Ry2q2YaVjoCFBd96MDy1QxyRDKWZ073mHKRss/provenance https://w3id.org/np/RAoI9yt_Ry2q2YaVjoCFBd96MDy1QxyRDKWZ073mHKRss http://www.nanopub.org/nschema#hasPublicationInfo https://w3id.org/np/RAoI9yt_Ry2q2YaVjoCFBd96MDy1QxyRDKWZ073mHKRss/pubinfo https://w3id.org/np/RAoI9yt_Ry2q2YaVjoCFBd96MDy1QxyRDKWZ073mHKRss http://www.w3.org/1999/02/22-rdf-syntax-ns#type http://www.nanopub.org/nschema#Nanopublication https://w3id.org/np/RAoI9yt_Ry2q2YaVjoCFBd96MDy1QxyRDKWZ073mHKRss/assertion https://w3id.org/delphi/resource/assessment/darwin1859-ch08-13--claim-test http://purl.org/dc/terms/description The artificial-cross table was read; 21 continuous traits had >= 8 F1 and F2 plants. For each trait the mean-scaled variance (variance of log values, or variance over squared mean for traits with zeros) was computed in F1 (n = 81 plants) and F2 (n = 36 plants); the median F2/F1 ratio and an exact sign test on the number of traits with ratio > 1 were evaluated against the pre-registered thresholds. F1 variance was also compared with both parental species. https://w3id.org/delphi/resource/assessment/darwin1859-ch08-13--claim-test http://www.w3.org/1999/02/22-rdf-syntax-ns#type https://w3id.org/delphi/ontology/Assessment https://w3id.org/delphi/resource/assessment/darwin1859-ch08-13--claim-test http://www.w3.org/2000/01/rdf-schema#comment Measured: 1.424136095275961 median across traits of the F2/F1 ratio of mean-scaled phenotypic variance (n = 21, 11 of 21 traits with ratio > 1; exact sign-test p = 0.5000; ratio range 0.03-8.01). Interpretation: Darwin's 'variable' is read as phenotypic variance among individuals of the same hybrid generation raised under common conditions, scaled by the trait mean so that traits of different magnitude are comparable. 'First generation' = F1 (cross between the two species), 'succeeding generations' = F2 (F1 x F1); backcrosses are not used because Darwin's statement concerns hybrids bred inter se. The claim's causal clause (disturbed reproductive system of the hybrids) is not tested; the quantitative-genetic explanation (segregation of parental alleles in F2) would produce the same pattern and is the modern reinterpretation. One plant cross is tested; the claim is stated for plant and animal hybrids generally. https://w3id.org/delphi/resource/assessment/darwin1859-ch08-13--claim-test http://www.w3.org/2000/01/rdf-schema#label Claim test of darwin1859-ch08-13: mixed, confidence 0.5 https://w3id.org/delphi/resource/assessment/darwin1859-ch08-13--claim-test http://www.w3.org/2000/01/rdf-schema#seeAlso https://github.com/fractastical/delphisci/blob/bf2af6ee0a84e23ffa6414ad7a0a50a8c276506e/test-data/claim-tests/darwin-origin/darwin1859-ch08-13/result.json https://w3id.org/delphi/resource/assessment/darwin1859-ch08-13--claim-test http://www.w3.org/ns/prov#wasAttributedTo https://w3id.org/delphi/resource/agent/delphisci-claim-tester-claude-fable-5-1 https://w3id.org/delphi/resource/assessment/darwin1859-ch08-13--claim-test https://w3id.org/delphi/ontology/admissibleDatasets Planned datasets: dryad-cakile-hybrids-B8QS5T https://w3id.org/delphi/resource/assessment/darwin1859-ch08-13--claim-test https://w3id.org/delphi/ontology/assessmentType claim-test/0.1.0 https://w3id.org/delphi/resource/assessment/darwin1859-ch08-13--claim-test https://w3id.org/delphi/ontology/dataKind biological https://w3id.org/delphi/resource/assessment/darwin1859-ch08-13--claim-test https://w3id.org/delphi/ontology/disconfirmingObservation Refuted if F2 hybrids are not more variable than F1 hybrids: the median F2/F1 variance ratio is <= 1.0, or F2 exceeds F1 in half or fewer of the traits. If the archive cannot be downloaded, the verdict is 'inconclusive' with reason 'data-unavailable'. https://w3id.org/delphi/resource/assessment/darwin1859-ch08-13--claim-test https://w3id.org/delphi/ontology/evidenceAgainst A single interspecific plant cross with 36 F2 plants; Darwin's generalisation covers many plant and animal hybrids. https://w3id.org/delphi/resource/assessment/darwin1859-ch08-13--claim-test https://w3id.org/delphi/ontology/evidenceAgainst Environmental variance in a common garden is included in both generations and cannot be separated from segregational variance here. https://w3id.org/delphi/resource/assessment/darwin1859-ch08-13--claim-test https://w3id.org/delphi/ontology/evidenceAgainst F1 plants come from many independent parental pairs (families), which adds between-family variance to F1 that a single-pair F1 would not have; this biases against the claim. https://w3id.org/delphi/resource/assessment/darwin1859-ch08-13--claim-test https://w3id.org/delphi/ontology/evidenceAgainst Mean-scaled variance compares dispersion across traits of different units but is sensitive to small means for count traits. https://w3id.org/delphi/resource/assessment/darwin1859-ch08-13--claim-test https://w3id.org/delphi/ontology/evidenceAgainst The claim's causal clause (disturbed reproductive system of hybrids) is not tested; Mendelian segregation in F2 is the modern explanation of the same pattern. https://w3id.org/delphi/resource/assessment/darwin1859-ch08-13--claim-test https://w3id.org/delphi/ontology/evidenceAgainst The outcome (median F2/F1 variance ratio between 1.0 and 1.5 with a bare, non-significant majority of traits more variable in F2) fell in a gap of the pre-registered decision rule; it is recorded as 'mixed'. By trait the pattern is strongly heterogeneous: floral and plant-size traits are 3-8 times more variable in F2, whereas seed mass, germination, phenology and fruit/seed counts are less variable in F2 than in F1. https://w3id.org/delphi/resource/assessment/darwin1859-ch08-13--claim-test https://w3id.org/delphi/ontology/expectedObservation Dataset: Dryad doi:10.25338/B8QS5T (Cakile edentula x C. maritima artificial crosses with F1, F2 and backcross generations; CC0). For every continuous trait recorded for both F1 and F2 individuals from the artificial crosses (identified from the data files after download; traits with < 8 individuals in either generation are excluded), compute the variance of log-transformed values (equivalent to a squared coefficient of variation for positive traits; for traits with zero or negative values use the variance of the trait divided by its squared mean) in F1 and in F2. Primary statistic: the median across traits of the variance ratio F2/F1. Pass ('supports') if the median ratio is >= 1.5 AND the F2 variance exceeds the F1 variance in a majority of traits with an exact binomial sign-test p < 0.05. 'Mixed' if F2 exceeds F1 in a majority of traits with p < 0.05 but the median ratio is between 1.0 and 1.5 (more variable, but not 'extremely' so relative to F1), or if the median ratio is >= 1.5 but the sign test is not significant. The comparison of F1 variance with parental variance is reported as an extra and does not enter the verdict. https://w3id.org/delphi/resource/assessment/darwin1859-ch08-13--claim-test https://w3id.org/delphi/ontology/failCriterion Refuted if F2 hybrids are not more variable than F1 hybrids: the median F2/F1 variance ratio is <= 1.0, or F2 exceeds F1 in half or fewer of the traits. If the archive cannot be downloaded, the verdict is 'inconclusive' with reason 'data-unavailable'. https://w3id.org/delphi/resource/assessment/darwin1859-ch08-13--claim-test https://w3id.org/delphi/ontology/hasConfidence 0.5 https://w3id.org/delphi/resource/assessment/darwin1859-ch08-13--claim-test https://w3id.org/delphi/ontology/hasEvidence https://w3id.org/delphi/resource/evidence/darwin1859-ch08-13--claim-test--dataset-1 https://w3id.org/delphi/resource/assessment/darwin1859-ch08-13--claim-test https://w3id.org/delphi/ontology/hasVerdict mixed https://w3id.org/delphi/resource/assessment/darwin1859-ch08-13--claim-test https://w3id.org/delphi/ontology/hypothesis If first-generation hybrids are only slightly variable while later generations are extremely variable, then in an experimental cross the phenotypic variance of F2 hybrids should exceed that of F1 hybrids for most measured traits, and F1 variance should be no greater than that of the parental species. https://w3id.org/delphi/resource/assessment/darwin1859-ch08-13--claim-test https://w3id.org/delphi/ontology/inferenceMethod The artificial-cross table was read; 21 continuous traits had >= 8 F1 and F2 plants. For each trait the mean-scaled variance (variance of log values, or variance over squared mean for traits with zeros) was computed in F1 (n = 81 plants) and F2 (n = 36 plants); the median F2/F1 ratio and an exact sign test on the number of traits with ratio > 1 were evaluated against the pre-registered thresholds. F1 variance was also compared with both parental species. https://w3id.org/delphi/resource/assessment/darwin1859-ch08-13--claim-test https://w3id.org/delphi/ontology/passCriterion Dataset: Dryad doi:10.25338/B8QS5T (Cakile edentula x C. maritima artificial crosses with F1, F2 and backcross generations; CC0). For every continuous trait recorded for both F1 and F2 individuals from the artificial crosses (identified from the data files after download; traits with < 8 individuals in either generation are excluded), compute the variance of log-transformed values (equivalent to a squared coefficient of variation for positive traits; for traits with zero or negative values use the variance of the trait divided by its squared mean) in F1 and in F2. Primary statistic: the median across traits of the variance ratio F2/F1. Pass ('supports') if the median ratio is >= 1.5 AND the F2 variance exceeds the F1 variance in a majority of traits with an exact binomial sign-test p < 0.05. 'Mixed' if F2 exceeds F1 in a majority of traits with p < 0.05 but the median ratio is between 1.0 and 1.5 (more variable, but not 'extremely' so relative to F1), or if the median ratio is >= 1.5 but the sign test is not significant. The comparison of F1 variance with parental variance is reported as an extra and does not enter the verdict. https://w3id.org/delphi/resource/assessment/darwin1859-ch08-13--claim-test https://w3id.org/delphi/ontology/preregistered false https://w3id.org/delphi/resource/claim/darwin1859-ch08-13 https://w3id.org/delphi/ontology/hasAssessment https://w3id.org/delphi/resource/assessment/darwin1859-ch08-13--claim-test https://w3id.org/delphi/resource/evidence/darwin1859-ch08-13--claim-test--dataset-1 http://purl.org/dc/terms/description individual-plant traits for parental, F1, F2 and backcross generations of an artificial interspecific cross https://w3id.org/delphi/resource/evidence/darwin1859-ch08-13--claim-test--dataset-1 http://purl.org/dc/terms/license CC0 1.0 https://w3id.org/delphi/resource/evidence/darwin1859-ch08-13--claim-test--dataset-1 http://www.w3.org/1999/02/22-rdf-syntax-ns#type https://w3id.org/delphi/ontology/EvidenceItem https://w3id.org/delphi/resource/evidence/darwin1859-ch08-13--claim-test--dataset-1 http://www.w3.org/2000/01/rdf-schema#label Dataset: Asymmetry in fitness-related traits of later-generation hybrids between two invasive species (Cakile edentula x C. maritima), file Chengjun_Experiment.csv https://w3id.org/delphi/resource/evidence/darwin1859-ch08-13--claim-test--dataset-1 http://www.w3.org/ns/prov#atLocation https://datadryad.org/api/v2/versions/105038/download https://w3id.org/delphi/resource/evidence/darwin1859-ch08-13--claim-test--dataset-1 http://www.w3.org/ns/prov#wasDerivedFrom https://datadryad.org/dataset/doi:10.25338/B8QS5T https://w3id.org/delphi/resource/evidence/darwin1859-ch08-13--claim-test--dataset-1 https://w3id.org/delphi/ontology/hasChecksum sha256:51227bc27534ac879ee1c11efb02e0bc34542bed92dea35e0bc003dce359a1d2 https://w3id.org/np/RAoI9yt_Ry2q2YaVjoCFBd96MDy1QxyRDKWZ073mHKRss/provenance https://w3id.org/delphi/resource/agent/delphisci-claim-tester-claude-fable-5-1 http://www.w3.org/1999/02/22-rdf-syntax-ns#type http://www.w3.org/ns/prov#SoftwareAgent https://w3id.org/delphi/resource/agent/delphisci-claim-tester-claude-fable-5-1 http://www.w3.org/2000/01/rdf-schema#label delphisci claim tester (claude-fable-5.1; 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