Convergent genome streamlining accompanies independent miniaturization in the world’s smallest fishes

Probably not a substantial claim: may not pass S3 (load-bearing).

Molecular dating used six undisputed Ostariophysi fossils as minimum-age constraints and a secondary constraint on the crown age of Otocephala.

“with divergence times calibrated using six undisputed Ostariophysi fossils as minimum-age constraints and a secondary constraint on the crown age of Otocephala (23).”

• cites [23] L. C. Hughes, Comprehensive phylogeny of ray-finned fishes (Actinopterygii) based on transcriptomic and genomic data. Proc. Natl. Acad. Sci. U.S.A. 115, 6249– 6254 (2018). PMC6004478 29760103 sourceDisputed

  The Phylogenomic Analyses and Gene Genealogy Interrogation section (page unavailable) says divergence times were estimated with more than 30 fossil calibrations, not six. Our copy also does not identify a secondary constraint on the crown age of Otocephala. (LLM, conf=0.84)

  Checked by a reasoning model — may be wrong.

  Experimental — accuracy not yet measured

May combine two claims.

OMArk single-copy completeness and consistency metrics did not reveal any systematic bias between annotation sources or between miniature and nonminiature species.

“OMArk single-copy completeness and consistency metrics did not reveal any systematic bias between annotation sources or between miniature and nonminiature species (SI Appendix, Fig. S20).”

• cites [94] Y. Nevers, Quality assessment of gene repertoire annotations with OMArk. Nat. Biotechnol. 43, 124– 133 (2025). PMC11738984 38383603 sourceDisputed

  In Results > Assembly and annotation comparisons (page unavailable), the paper reports small differences between Ensembl and NCBI annotations and says they confirm that OMArk is slightly biased by the origin of its reference proteomes. The Discussion likewise cautions about this bias. The passages do not address miniature versus nonminiature species. (LLM, conf=0.87)

  Checked by a reasoning model — may be wrong.

  Experimental — accuracy not yet measured

May combine two claims.

In Cypriniformes, miniaturization has evolved repeatedly, producing two distinct forms: proportioned dwarfs and progenetic miniatures.

“In Cypriniformes, the most species-rich order of freshwater fishes, miniaturization has evolved repeatedly, producing two distinct forms: proportioned dwarfs, which closely resemble smaller versions of larger relatives, and progenetic miniatures, which retain larval traits due to developmental truncation into adulthood.”

• cites [10] L. Rüber, M. Kottelat, H. H. Tan, P. K. Ng, R. Britz, Evolution of miniaturization and the phylogenetic position of Paedocypris, comprising the world’s smallest vertebrate. BMC Evol. Biol. 7, 38 (2007). PMC1838906 17355618 sourceSupported

May combine two claims.

Multiple loach (Cobitoidei) families have consistently small genome sizes, with several falling below or approaching the genome size of pufferfishes (346.5 to 385.0 Mb).

“A particularly striking finding were the consistently small genome sizes observed across multiple loach (Cobitoidei) families (SI Appendix, Fig. S2): Balitoridae (347.9 to 537.5 Mb), Barbuccidae (379.5 Mb), Gastromyzontidae (411.6 to 474.3 Mb), Vaillantellidae (427.5 Mb), Serpenticobitidae (440.3 Mb), and Ellopostomatidae (452.7 Mb), with several falling below or approaching the genome size of puf”

• cites [30] S. Aparicio, Whole-genome shotgun assembly and analysis of the genome of Fugu rubripes. Science 297, 1301– 1310 (2002). 12142439 sourceNot checked — no full text of the source
• cites [31] K. Liu, Patterns and processes of genomic evolution inferred from the ten smallest vertebrate genomes. Adv. Sci. 12, e17251 (2025). PMC12520575 40928031 sourcePartly supported

  The Results section (Genome Assembly, Annotation, and TAD Organization; page unavailable) reports pufferfish genome assemblies of 346.48–385.03 Mb, matching the comparison range. The paper does not report genome sizes for the listed loach families or establish that their genomes approach that range. (LLM, conf=0.88)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Progenetic miniatures undergo profound developmental truncation, giving rise to striking morphological novelties not shown in their larger relatives, while proportioned dwarfs retain a normal developmental trajectory despite their reduced body size.

“Progenetic miniatures undergo profound developmental truncation, giving rise to striking morphological novelties not shown in their larger relatives, while proportioned dwarfs retain a normal developmental trajectory despite their reduced body size (e.g., refs. 5, 12, 14, 41, and 42).”

• cites [5] R. Britz, K. W. Conway, Danionella dracula, an escape from the cypriniform Bauplan via developmental truncation? J. Morphol. 277, 147– 166 (2016). 26589666 sourceNot checked — no full text of the source
• cites [12] R. Britz, K. W. Conway, L. Rüber, Spectacular morphological novelty in a miniature cyprinid fish, Danionella dracula n. sp. Proc. R. Soc. B 276, 2179– 2186 (2009). PMC2677611 19324738 sourcePartly supported

  Split into 2 atoms — 1 confirmed, 1 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  Experimental — accuracy not yet measured
• cites [14] R. Britz, K. W. Conway, Osteology of Paedocypris, a miniature and highly developmentally truncated fish (Teleostei: Ostariophysi: Cyprinidae). J. Morphol. 270, 389– 412 (2009). 19107939 sourceNot checked — no full text of the source

May combine two claims.

The decoupling of genome size from body size reduction is consistent with the broader C-value enigma, reinforcing that genome size evolution is governed by mechanisms largely independent of organismal size or complexity.

“This decoupling of genome size from body size reduction is consistent with the broader C-value enigma, reinforcing that genome size evolution is governed by mechanisms largely independent of organismal size or complexity (47, 48).”

• cites [47] T. R. Gregory, Coincidence, coevolution, or causation? DNA content, cell size, and the C-value enigma. Biol. Rev. 76, 65– 101 (2001). 11325054 sourcePartly supported

  The Conclusions (page not specified) identify the lack of correlation between genome size and organismal complexity as the C-value enigma. But the paper does not establish that genome-size evolution is largely independent of body size: Evolutionary Implications reports positive associations with body size in many plants and invertebrates. It also does not address the particular decoupling from body-size reduction described in the citing sentence. (LLM, conf=0.86)

  Experimental — accuracy not yet measured
• cites [48] H. C. Liedtke, D. J. Gower, M. Wilkinson, I. Gomez-Mestre, Macroevolutionary shift in the size of amphibian genomes and the role of life history and climate. Nat. Ecol. Evol. 2, 1792– 1799 (2018). 30250158 sourceNot checked — no full text of the source

May combine two claims.

Both loaches/Psilorhynchidae and progenetic miniatures inhabit physiologically demanding environments, which has been linked to selection for smaller genomes through the relationship between cell size, nuclear DNA content, and metabolic rate.

“Both groups therefore inhabit physiologically demanding environments, which has been linked to selection for smaller genomes through the relationship between cell size, nuclear DNA content, and metabolic rate (e.g., refs. 45, 47, and 51–53).”

• cites [45] J. Blommaert, Genome size evolution: Towards new model systems for old questions. Proc. R. Soc. B 287, 20201441 (2020). PMC7482279 32842932 sourcePartly supported

  Split into 2 atoms — 1 confirmed, 1 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  Experimental — accuracy not yet measured
• cites [47] T. R. Gregory, Coincidence, coevolution, or causation? DNA content, cell size, and the C-value enigma. Biol. Rev. 76, 65– 101 (2001). 11325054 sourcePartly supported

  Split into 2 atoms — 1 confirmed, 1 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  Experimental — accuracy not yet measured
• cites [51] J. D. Gardner, M. Laurin, C. L. Organ, The relationship between genome size and metabolic rate in extant vertebrates. Philos. Trans. R. Soc. B: Biol. Sci. 375, 20190146 (2020). PMC7017434 31928192 sourcePartly supported

  Split into 2 atoms — 0 confirmed, 2 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  Experimental — accuracy not yet measured
• cites [52] D. C. Hardie, P. D. N. Hebert, The nucleotypic effects of cellular DNA content in cartilaginous and ray-finned fishes. Genome 46, 683– 706 (2003). 12897876 sourceNot checked — no full text of the source
• cites [53] A. Kapusta, A. Suh, C. Feschotte, Dynamics of genome size evolution in birds and mammals. Proc. Natl. Acad. Sci. U.S.A. 114, E1460– E1469 (2017). PMC5338432 28179571 sourceSupported

May combine two claims.

Depletion of LTR elements and DNA transposons suggests either reduced transposition activity, increased elimination of newly inserted elements, or both, consistent with mechanisms proposed for genome compaction in other vertebrates with streamlined genomes.

“Depletion of these elements suggests either reduced transposition activity, increased elimination of newly inserted elements, or both, consistent with mechanisms proposed for genome compaction in other vertebrates with streamlined genomes (31, 43, 53, 56).”

• cites [31] K. Liu, Patterns and processes of genomic evolution inferred from the ten smallest vertebrate genomes. Adv. Sci. 12, e17251 (2025). PMC12520575 40928031 sourcePartly supported

  Split into 2 atoms — 1 confirmed, 1 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  Experimental — accuracy not yet measured
• cites [43] A. Canapa, M. Barucca, M. A. Biscotti, M. Forconi, E. Olmo, Transposons, genome size, and evolutionary insights in animals. Cytogenet. Genome Res. 147, 217– 239 (2015). 26967166 sourceNot checked — no full text of the source
• cites [53] A. Kapusta, A. Suh, C. Feschotte, Dynamics of genome size evolution in birds and mammals. Proc. Natl. Acad. Sci. U.S.A. 114, E1460– E1469 (2017). PMC5338432 28179571 sourcePartly supported

  Split into 2 atoms — 1 confirmed, 1 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  Experimental — accuracy not yet measured

May combine two claims.

The primary causes of TE depletion were reduction of LTR elements and DNA transposons, which are highly active element classes capable of rapid genome expansion.

“The primary causes of TE depletion were reduction of LTR elements and DNA transposons which are highly active element classes capable of rapid genome expansion (57–62).”

• cites [57] D. Chalopin, M. Naville, F. Plard, D. Galiana, J.-N. Volff, Comparative analysis of transposable elements highlights mobilome diversity and evolution in vertebrates. Genome Biol. Evol. 7, 567– 580 (2015). PMC4350176 25577199 sourcePartly supported

  The Results (Lineage-Specific TE Activity during Vertebrate Evolution; page unavailable) describe bursts of LTR retroelements and DNA transposons, supporting their capacity to expand in genomes. The paper does not identify reductions in those two classes as the primary causes of TE depletion; the Discussion (Diversity of TE Contribution to Genome Size in Vertebrates; page unavailable) instead discusses variation in TE activity and elimination rates more generally. (LLM, conf=0.84)

  Experimental — accuracy not yet measured
• cites [58] B. Gao, The contribution of transposable elements to size variations between four teleost genomes. Mobile DNA 7, 4 (2016). PMC4746887 26862351 sourcePartly supported

  The Results section (‘Dramatically different expansion of TEs across the four teleost genomes’; page unavailable) reports lower abundances of both DNA transposons and LTR retrotransposons in the smaller genomes. But the Abstract Results and Discussion (‘TE proliferation and genomic expansion in teleosts’; pages unavailable) identify DNA transposons—not LTR elements and DNA transposons jointly—as the main contributor to the differences. The paper compares TE accumulation across four teleosts; it does not establish depletion caused by reductions in both classes. (LLM, conf=0.86)

  Experimental — accuracy not yet measured
• cites [59] B. Piegu, Doubling genome size without polyploidization: Dynamics of retrotransposition-driven genomic expansions in Oryza australiensis, a wild relative of rice. Genome Res. 16, 1262– 1269 (2006). PMC1581435 16963705 sourcePartly supported

  In “The genomic amplification of O. australiensis occurred after its speciation” (page unavailable), the paper says LTR-retrotransposons can be partially eliminated through recombination. It also describes LTR-retrotransposons as drivers of genome expansion. It does not identify reductions in both LTR elements and DNA transposons as the primary causes of the TE depletion claimed here. (LLM, conf=0.86)

  Experimental — accuracy not yet measured
• cites [60] A. O. Rubio, Anuran genome size evolution is driven by relatively recent retrotransposon activity and by life history. BMC Genomics 27, 74 (2025). PMC12822217 41413442 sourcePartly supported

  The Discussion section on transposable-element families says LTR elements can proliferate in bursts and rapidly increase genome size; it also links a DNA transposon family to genome expansion. It does not identify reductions in LTR elements and DNA transposons as the primary causes of TE depletion. The indexed passages provide no page numbers. (LLM, conf=0.84)

  Experimental — accuracy not yet measured
• cites [61] C. G. Sotero-Caio, R. N. Platt, A. Suh, D. A. Ray, Evolution and diversity of transposable elements in vertebrate genomes. Genome Biol. Evol. 9, 161– 177 (2017). PMC5381603 28158585 sourcePartly supported

  The Introduction says TE content is linked to genome size, and The Future links LTR retrotransposons to large salamander genomes; the Eutheria section describes substantial DNA-transposon accumulation in bats. These passages support the capacity of these elements to expand genomes, but the paper does not identify reductions in LTR elements and DNA transposons as the primary causes of the claimed TE depletion. (LLM, conf=0.84)

  Experimental — accuracy not yet measured
• cites [62] C. Sun, R. L. Mueller, Hellbender genome sequences shed light on genomic expansion at the base of crown salamanders. Genome Biol. Evol. 6, 1818– 1829 (2014). PMC4122941 25115007 sourcePartly supported

  The Results section, “Comparison of Cryptobranchus TE Levels with Other Vertebrate Genomes” (page unavailable), links high LTR retrotransposon levels to salamander genomic expansion. The Discussion section, “DNA Loss and Genomic Expansion” (page unavailable), notes variation in LTR retrotransposons and DNA transposons, but does not identify reductions in those classes as the primary causes of TE depletion. (LLM, conf=0.83)

  Experimental — accuracy not yet measured

May combine two claims.

The genome compaction previously reported in Paedocypris extends to progenetic miniatures more broadly, while it is not a feature of proportioned dwarfism.

“This extends the genome compaction previously reported in Paedocypris (18) to progenetic miniatures more broadly, while confirming that it is not a feature of proportioned dwarfism.”

• cites [18] M. Malmstrøm, The most developmentally truncated fishes show extensive hox gene loss and miniaturized genomes. Genome Biol. Evol. 10, 1088– 1103 (2018). PMC5906920 29684203 sourcePartly supported

  The Results (‘Genome Miniaturization through Intron Shortening’) report substantially smaller genomes in two Paedocypris species. But the Discussion says genome sizes of proportionate dwarfs remain to be examined and does not establish genome compaction in progenetic miniatures beyond Paedocypris. The broader extension and the asserted absence of compaction in proportionate dwarfs are therefore unsupported. (LLM, conf=0.90)

  Experimental — accuracy not yet measured

Classified as probably not a substantial claim. May combine two claims.

Genome compaction has been documented across diverse vertebrate and invertebrate lineages irrespective of body size, with compact genomes consistently showing predictable signatures of repeat depletion and structural simplification.

“Genome compaction has been documented across diverse vertebrate and invertebrate lineages irrespective of body size, with compact genomes consistently showing predictable signatures of repeat depletion and structural simplification (e.g., refs. 31, 55, and 56).”

• cites [31] K. Liu, Patterns and processes of genomic evolution inferred from the ten smallest vertebrate genomes. Adv. Sci. 12, e17251 (2025). PMC12520575 40928031 sourcePartly supported

  The Results sections on functional composition and mechanisms preserving compactness (page not provided) report short introns in pufferfish and restrained transposable-element insertion in compact Takifugu genomes. They do not establish the claim across invertebrates, irrespective of body size, or show that repeat depletion and structural simplification are consistent signatures across compact genomes. (LLM, conf=0.87)

  Experimental — accuracy not yet measured
• cites [55] J. L. Kelley, Compact genome of the Antarctic midge is likely an adaptation to an extreme environment. Nat Commun 5, 4611 (2014). PMC4164542 25118180 sourcePartly supported

  The Results link the Antarctic midge’s compact genome to fewer repeats and transposable elements and shorter introns. The Discussion reports similar reductions in non-genic DNA in a plant and a pufferfish. These examples support compaction in more than one lineage, but the paper does not establish that the pattern is consistent across diverse vertebrates and invertebrates or independent of body size. (LLM, conf=0.85)

  Experimental — accuracy not yet measured
• cites [56] S. Lamichhaney, A bird-like genome from a frog: Mechanisms of genome size reduction in the ornate burrowing frog, Platyplectrum ornatum. Proc. Natl. Acad. Sci. U.S.A. 118, e2011649118 (2021). PMC7980411 33836564 sourcePartly supported

  The Discussion (page unavailable) associates smaller genomes in fish and insects with reduced repeat content, and the Results report shorter introns in the compact frog genome. The paper does not establish that these signatures occur consistently across vertebrates and invertebrates or irrespective of body size; it describes repeat depletion as a prevalent trend and notes that the tight correlation between repeat abundance and genome size has been questioned. (LLM, conf=0.85)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing).

Miniaturization is comparatively frequent in teleost fishes.

“Miniaturization is comparatively frequent in teleost fishes (10, 11, 40).”

• cites [10] L. Rüber, M. Kottelat, H. H. Tan, P. K. Ng, R. Britz, Evolution of miniaturization and the phylogenetic position of Paedocypris, comprising the world’s smallest vertebrate. BMC Evol. Biol. 7, 38 (2007). PMC1838906 17355618 sourceSupported
• cites [11] S. H. Weitzman, R. P. Vari, Miniaturization in South American freshwater fishes; an overview and discussion. Proc. Biol. Soc. Washington 101, 444– 465 (1988).Not checked yet

  Not checked in the free run.

• cites [40] M. Kottelat, C. Vidthayanon, Boraras micros, a new genus and species of minute freshwater fish from Thailand (Teleostei: Cyprinidae). Ichthyol. Explor. Freshwaters 4, 161– 176 (1993).Not checked yet

  Not checked in the free run.

May combine two claims.

Genome size is tightly coupled to cell size and, in turn, to cell-division and developmental rate across fishes and other vertebrates.

“Genome size is tightly coupled to cell size and, in turn, to cell-division and developmental rate across fishes and other vertebrates (e.g., refs. 47, 48, 52, and 54).”

• cites [47] T. R. Gregory, Coincidence, coevolution, or causation? DNA content, cell size, and the C-value enigma. Biol. Rev. 76, 65– 101 (2001). 11325054 sourceSupported
• cites [48] H. C. Liedtke, D. J. Gower, M. Wilkinson, I. Gomez-Mestre, Macroevolutionary shift in the size of amphibian genomes and the role of life history and climate. Nat. Ecol. Evol. 2, 1792– 1799 (2018). 30250158 sourceNot checked — no full text of the source
• cites [52] D. C. Hardie, P. D. N. Hebert, The nucleotypic effects of cellular DNA content in cartilaginous and ray-finned fishes. Genome 46, 683– 706 (2003). 12897876 sourceNot checked — no full text of the source

May combine two claims.

K-mer-based genome size estimates correlated strongly with independent cytometric measurements from the Animal Genome Size Database (r = 0.791, P < 0.0001), confirming their suitability for comparative analysis.

“K-mer–based estimates correlated strongly with independent cytometric measurements from the Animal Genome Size Database (r = 0.791, P < 0.0001; SI Appendix, Fig. S1 and Table S11), confirming their suitability for comparative analysis (81).”

• cites [81] T. A. Elliott, T. R. Gregory, What’s in a genome? The C-value enigma and the evolution of eukaryotic genome content. Phil. Trans. R. Soc. B 370, 20140331 (2015). PMC4571570 26323762 sourcePartly supported

  The Results report a strong correlation between genome-assembly estimates and densitometric or flow-cytometric estimates (r = 0.9527, p < 0.0001), and the Methods identify the Animal Genome Size Database as one source of cytometric data. The paper does not report a k-mer-based comparison or the claimed r = 0.791; its Discussion also cautions that sequence-based estimates tend to be lower, especially for larger genomes. No page numbers were provided in our copy. (LLM, conf=0.90)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Eight independent MCMC chains were run and convergence was assessed from effective sample sizes in Tracer.

“We ran eight independent MCMC chains and assessed convergence from effective sample sizes in Tracer (78)”

• cites [78] A. Rambaut, A. J. Drummond, D. Xie, G. Baele, M. A. Suchard, Posterior summarization in Bayesian phylogenetics using Tracer 1.7. Syst. Biol. 67, 901– 904 (2018). PMC6101584 29718447 sourceSupported

May combine two claims.

Median gene lengths and intron lengths did not show systematic differences between annotation sources, confirming that these metrics are comparable across our dataset.

“Median gene lengths and intron lengths did not show systematic differences between annotation sources (SI Appendix, Figs. S22–S24), confirming that these metrics are comparable across our dataset.”

• cites [20] H. Sudasinghe, Reference genomes of four miniature and non-miniature cypriniform fishes inhabiting acidic peat-swamp forest blackwaters of Southeast Asia. bioRxiv [Preprint] (2026). 10.64898/2026.03.21.713365 (Accessed 24 March 2026). sourceCould not verify

  The indexed passages do not address whether median gene and intron lengths differ between annotation sources. Searches for the claimed comparison and for annotation sources with Figs. S22–S24 found no passage reporting that comparison or establishing comparability across the dataset. (LLM, conf=0.74)

  Experimental — accuracy not yet measured

May combine two claims.

Genome compaction in pufferfishes combines TE/repeat reduction via suppression of transposable-element activity along with genome-wide intron shortening rather than intron loss.

“Genome compaction in pufferfishes likewise combines TE/repeat reduction via suppression of transposable-element activity (31) along with genome-wide intron shortening rather than intron loss (30, 31, 71)”

• cites [31] K. Liu, Patterns and processes of genomic evolution inferred from the ten smallest vertebrate genomes. Adv. Sci. 12, e17251 (2025). PMC12520575 40928031 sourcePartly supported

  The Results sections on functional composition and genome compactness report that pufferfish have the shortest introns among vertebrates and that reduced TE propagation contributes to their compact genomes (page numbers unavailable). The copy does not establish that intron shortening occurred rather than intron loss. (LLM, conf=0.85)

  Experimental — accuracy not yet measured
• cites [30] S. Aparicio, Whole-genome shotgun assembly and analysis of the genome of Fugu rubripes. Science 297, 1301– 1310 (2002). 12142439 sourceNot checked — no full text of the source
• cites [71] Y.-H. Loh, S. Brenner, B. Venkatesh, Investigation of loss and gain of introns in the compact genomes of pufferfishes (Fugu and Tetraodon). Mol. Biol. Evol. 25, 526– 535 (2008). 18089580 sourcePartly supported

  The section on pufferfish genome compaction says compaction was accomplished mainly by shortening introns and intergenic regions, not by a higher rate of loss of entire introns. The Discussion also reports fewer TE copies in pufferfishes than in mammals, but explicitly says TE activity is higher in pufferfishes; it does not support reduction through suppression of TE activity. Page numbers are unavailable in our copy. (LLM, conf=0.89)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Although efficient selection under large effective population sizes is predicted to purge TEs, recent animal-wide analyses find no association between effective population size and either genome size or TE content.

“Although efficient selection under large effective population sizes is predicted to purge TEs (66), recent animal-wide analyses find no association between effective population size and either genome size or TE content (67).”

• cites [66] M. Lynch, The Origins of Genome Architecture (Sinauer Associates, 2007).Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [67] A. Marino, G. Debaecker, A.-S. Fiston-Lavier, A. Haudry, B. Nabholz, Effective population size does not explain long-term variation in genome size and transposable element content in animals. eLife 13, RP100574 (2025). PMC12274066 40679280 sourceSupported

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

EDTA was run with sensitive options to enable RepeatModeler-based discovery of additional repeat families and whole-genome TE annotation, and RepeatMasker was run with slow search to maximize sensitivity.

“EDTA was run with the --sensitive 1 option to enable RepeatModeler-based discovery of additional repeat families (90) and with --anno 1 to perform whole-genome TE annotation following library construction. The resulting custom TE libraries were subsequently used to mask each genome assembly using RepeatMasker with the slow search option to maximize sensitivity (91).”

• cites [90] J. M. Flynn, RepeatModeler2 for automated genomic discovery of transposable element families. Proc. Natl. Acad. Sci. U.S.A. 117, 9451– 9457 (2020). PMC7196820 32300014 sourceSupported
• cites [91] A. F. A. Smit, R. Hubley, P. Green, RepeatMasker Open-4.0 (2015). Accessed 14 January 2026.Not checked yet

  Not checked in the free run.

Classified as probably not a substantial claim.

The ASTRAL-IV topology was chosen because it showed high overall congruence across alternative phylogenomic inference methods in the original study.

“We chose this topology because it showed high overall congruence across alternative phylogenomic inference methods in the original study.”

• cites [19] H. Sudasinghe, Phylogenomics of Cypriniformes, the most diverse order of freshwater fishes: Consensus, challenges and limitations. bioRxiv [Preprint] (2026). http://biorxiv.org/lookup/doi/10.64898/2026.01.14.699467 (Accessed 17 January 2026). sourceSupported

May combine two claims.

Intron lengths exhibit substantial biological variation and are less affected by annotation pipeline differences, as intron boundaries are defined by conserved splice sites.

“In contrast, intron lengths exhibit substantial biological variation and are less affected by annotation pipeline differences, as intron boundaries are defined by conserved splice sites (69, 95, 97, 98).”

• cites [69] D. C. Jeffares, T. Mourier, D. Penny, The biology of intron gain and loss. Trends Genet. 22, 16– 22 (2006). 16290250 sourceNot checked — no full text of the source
• cites [95] M. Long, M. Deutsch, Intron-exon structures of eukaryotic model organisms. Nucleic Acids Res. 27, 3219– 3228 (1999). PMC148551 10454621 sourcePartly supported

  The sections “Intron-exon structures in the overall database” and “Intron-exon structures in the 10 model organisms” report substantial variation in intron lengths. “Exon databases” describes checking splice-site sequences to exclude erroneous intron submissions, but the paper does not compare annotation pipelines or establish that intron lengths are less affected by pipeline differences. Page numbers are unavailable in our copy. (LLM, conf=0.88)

  Experimental — accuracy not yet measured
• cites [97] M. K. Sakharkar, V. T. K. Chow, P. Kangueane, Distributions of exons and introns in the human genome. In Silico Biol. 4, 387– 393 (2004). 15217358 sourceNot checked — no full text of the source

Classified as probably not a substantial claim.

Exon lengths are highly conserved due to functional constraints on protein-coding sequences.

“While exon lengths are highly conserved due to functional constraints on protein-coding sequences (95–97)”

• cites [95] M. Long, M. Deutsch, Intron-exon structures of eukaryotic model organisms. Nucleic Acids Res. 27, 3219– 3228 (1999). PMC148551 10454621 sourcePartly supported

  The section ‘Intron-exon structures in the overall database’ reports that exon lengths have a much tighter distribution than intron lengths, with most exons 30–40 residues long. It does not establish that exon lengths are conserved across evolution or attribute their distribution to functional constraints on protein-coding sequences; the functional constraints discussed in the Introduction concern intron splicing. Page numbers were not available in our copy. (LLM, conf=0.84)

  Experimental — accuracy not yet measured
• cites [96] Y. Nevers, N. M. Glover, C. Dessimoz, O. Lecompte, Protein length distribution is remarkably uniform across the tree of life. Genome Biol. 24, 135 (2023). PMC10251718 37291671 sourceCould not verify

  The Conclusions report consistent protein-length distributions across species, and the Discussion suggests selective pressure on protein length. Neither passage establishes that exon lengths are conserved or that functional constraints cause their conservation. A search for exon-length conservation found no passage addressing that claim. (LLM, conf=0.75)

  Experimental — accuracy not yet measured
• cites [97] M. K. Sakharkar, V. T. K. Chow, P. Kangueane, Distributions of exons and introns in the human genome. In Silico Biol. 4, 387– 393 (2004). 15217358 sourceNot checked — no full text of the source

May combine two claims.

Low-divergence copies of transposable elements represent more recent insertions, and highly diverged copies reflect older, inactive elements.

“Low-divergence copies represent more recent insertions and highly diverged copies reflect older, inactive elements (53, 57, 61).”

• cites [53] A. Kapusta, A. Suh, C. Feschotte, Dynamics of genome size evolution in birds and mammals. Proc. Natl. Acad. Sci. U.S.A. 114, E1460– E1469 (2017). PMC5338432 28179571 sourcePartly supported

  In “Genome size evolution as the integration of gain and loss of DNA” (page unavailable), the paper says it infers TE insertion age from divergence from the family consensus sequence. “Determination of ancient versus lineage specific TEs” describes using each copy’s corrected divergence to distinguish older from lineage-specific TE-derived DNA. These passages support the age relationship, but do not establish that highly diverged copies are inactive. (LLM, conf=0.86)

  Experimental — accuracy not yet measured
• cites [57] D. Chalopin, M. Naville, F. Plard, D. Galiana, J.-N. Volff, Comparative analysis of transposable elements highlights mobilome diversity and evolution in vertebrates. Genome Biol. Evol. 7, 567– 580 (2015). PMC4350176 25577199 sourcePartly supported

  The Results section (“Lineage-Specific TE Activity during Vertebrate Evolution”) says low-divergence copies indicate recent activity and highly divergent copies come from ancient transposition events. The Fig. 4 caption describes the latter as potentially ancient or degenerated, but does not establish that highly diverged copies are inactive. (LLM, conf=0.88)

  Experimental — accuracy not yet measured
• cites [61] C. G. Sotero-Caio, R. N. Platt, A. Suh, D. A. Ray, Evolution and diversity of transposable elements in vertebrate genomes. Genome Biol. Evol. 9, 161– 177 (2017). PMC5381603 28158585 sourcePartly supported

  The Squamata section (page unavailable) links genetic distance with recent TE activity and describes older elements as more heavily mutated. The Annotating TEs section also says overestimated divergence makes TE accumulations appear older. Neither passage establishes that highly diverged copies are necessarily inactive, so that part of the claim is unsupported. (LLM, conf=0.83)

  Experimental — accuracy not yet measured

Classified as probably not a substantial claim.

Teleost introns fall into two functional classes: compact introns containing primarily sequences necessary for efficient splicing, and long introns disproportionately harboring regulatory elements and conserved sequences maintained across vertebrates.

“This is consistent with the observation that teleost introns fall into two functional classes: compact introns containing primarily sequences necessary for efficient splicing, and long introns disproportionately harboring regulatory elements and conserved sequences maintained across vertebrates (68).”

• cites [68] L. M. Jakt, A. Dubin, S. D. Johansen, Intron size minimisation in teleosts. BMC Genomics 23, 628 (2022). PMC9438311 36050638 sourcePartly supported

  Split into 2 atoms — 0 confirmed, 2 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  Experimental — accuracy not yet measured

May combine two claims.

Miniaturization is a derived condition within Cypriniformes, with the ancestral state at the root inferred as nonminiature.

“Stochastic character mapping on the time-calibrated phylogeny revealed that miniaturization is a derived condition within Cypriniformes, with the ancestral state at the root inferred as nonminiature (Fig. 2A).”

May combine two claims.

Body size and genome size are decoupled in most clades, notably in Danionidae, where most species are small-bodied despite spanning a wide genome size range.

“Ancestral state reconstruction of body size revealed a broadly similar pattern, with body size and genome size decoupled in most clades, notably in Danionidae, where most species are small-bodied despite spanning a wide genome size range (Fig. 2C).”

May combine two claims.

Progenetic miniatures had an approximate 25% genome size reduction relative to nonminiatures, equivalent to a reduction of roughly 190 Mb for a typical nonminiature cypriniform genome.

“Progenetic miniatures had an approximate 25% genome size reduction relative to nonminiatures, which is equivalent to a reduction of roughly 190 Mb for a typical nonminiature cypriniform genome (Fig. 3B).”

May combine two claims.

Progenetic miniatures showed a consistent negative trend in genome size that was directionally consistent across all model structures and independent of ploidy and body size as covariates (β = −0.126, SE = 0.082, t = −1.533, P = 0.126).

“However, progenetic miniatures showed a consistent negative trend that was directionally consistent across all model structures and independent of ploidy and body size as covariates (β = −0.126, SE = 0.082, t = −1.533, P = 0.126).”

May combine two claims.

Progenetic miniatures, but not proportioned dwarfs, exhibit consistent genome size reductions.

“By reconstructing the evolutionary history of miniaturization and performing comparative genomic analyses, we show that progenetic miniatures, but not proportioned dwarfs, exhibit consistent genome size reductions.”

May combine two claims.

Loaches showed consistently smaller genome sizes than Cyprinoidei overall, with the clade comprising Serpenticobitidae, Gastromyzontidae, Barbuccidae, and Balitoridae exhibiting particularly marked genome size reduction.

“Loaches showed consistently smaller genome sizes than Cyprinoidei overall, with the clade comprising Serpenticobitidae, Gastromyzontidae, Barbuccidae, and Balitoridae exhibiting particularly marked genome size reduction.”

May combine two claims.

Progenetic miniaturization evolved rarely, with a median of four independent origins per reconstruction (95% range: 2 to 6), representing three independent origins across Paedocypris, Danionella, and Sundadanio + Fangfangia, all within Cyprinoidei.

“Progenetic miniaturization evolved rarely, with a median of four independent origins per reconstruction (95% range: 2 to 6), representing three independent origins across the four recognized genera (Paedocypris, Danionella, and Sundadanio + Fangfangia), all within Cyprinoidei.”

May combine two claims.

Proportioned dwarfism evolved far more frequently, with a median of 18 independent origins per reconstruction (95% range: 15 to 19), concentrated predominantly within Danionidae, with additional origins in Cyprinidae, Tanichthyidae, Cobitidae, Balitoridae, and Barbuccidae.

“Proportioned dwarfism evolved far more frequently, with a median of 18 independent origins per reconstruction (95% range: 15 to 19), concentrated predominantly within Danionidae, but with additional origins in Cyprinidae, Tanichthyidae, Cobitidae, Balitoridae, and Barbuccidae.”

May combine two claims.

The comparison restricted to progenetic miniatures vs. nonminiatures approached significance (β = 13.877, SE = 7.984, P = 0.092), corresponding to approximately 14% more TE content in nonminiature genomes.

“the comparison restricted to progenetic miniatures vs. nonminiatures approached significance (β = 13.877, SE = 7.984, P = 0.092), corresponding to approximately 14% more TE content in nonminiature genomes.”

May combine two claims.

Genome size within most cypriniform families was remarkably conserved (intrafamilial fold variation 1.0 to 1.5), with only Cobitidae, Cyprinidae, and Danionidae exceeding threefold variation.

“Genome size within most families was remarkably conserved (intrafamilial fold variation: 1.0 to 1.5), with only Cobitidae, Cyprinidae, and Danionidae exceeding threefold variation (SI Appendix, Fig. S2).”

May combine two claims.

Both genome size and body size showed strong phylogenetic signal (genome size: Pagel's λ = 1.000, K = 1.110, P = 0.001; body size: Pagel's λ = 0.946, K = 0.322, P = 0.001).

“Both traits showed strong phylogenetic signal (genome size: Pagel’s λ = 1.000, K = 1.110, P = 0.001; body size: Pagel’s λ = 0.946, K = 0.322, P = 0.001)”

May combine two claims.

Ploidy was the overwhelmingly dominant predictor of genome size variation (β = 0.258, SE = 0.029, P < 2.2 × 10−16; R2 = 0.209), while body size was not a significant predictor after accounting for ploidy and miniaturization status.

“Ploidy emerged as the overwhelmingly dominant predictor of genome size variation (β = 0.258, SE = 0.029, P < 2.2 × 10−16; R2 = 0.209), while body size was not a significant predictor after accounting for ploidy and miniaturization status.”

May combine two claims.

Across 261 cypriniform species, median haploid genome size was 752.7 Mb, with a sevenfold span from 347.9 Mb in Homalopterula gymnogaster to 2,509.8 Mb in Cycleptus sp.

“Across the 261 species, the median haploid genome size was 752.7 Mb, with a sevenfold span ranging from 347.9 Mb in the balitorid loach Homalopterula gymnogaster to 2,509.8 Mb in the polyploid Cycleptus sp. (Catostomidae).”

May combine two claims.

Progenetic miniaturization arose rarely, with only three independent origins all within Cyprinoidei.

“progenetic miniaturization arose rarely, with only three independent origins all within Cyprinoidei”

May combine two claims.

Progenetic miniatures showed a directionally consistent ~25% genome size reduction relative to nonminiatures, robust across all model structures and independent of ploidy and body size.

“Progenetic miniatures, however, showed a directionally consistent ~25% genome size reduction relative to nonminiatures, robust across all model structures and independent of ploidy and body size.”

May combine two claims.

The proportion of compact vs. long introns and the median number of introns per gene did not differ significantly between progenetic miniatures and nonminiatures.

“In contrast to the pronounced intron length differences, the proportion of compact vs. long introns and the median number of introns per gene did not differ significantly between progenetic miniatures and nonminiatures (SI Appendix, Figs. S18 and S19)”

May combine two claims. The quote only partly states this claim.

Proportioned dwarfism evolved far more frequently than progenetic miniaturization, concentrated predominantly within Danionidae.

“while proportioned dwarfism evolved far more frequently, concentrated predominantly within Danionidae.”

May combine two claims.

Consistently small genome sizes were found across multiple loach families, with Serpenticobitidae, Gastromyzontidae, Barbuccidae, and Balitoridae showing particularly marked reductions.

“A particularly striking finding were the consistently small genome sizes across multiple loach families, with Serpenticobitidae, Gastromyzontidae, Barbuccidae, and Balitoridae showing particularly marked reductions.”

May combine two claims.

DNA transposons and LTR elements were both significantly reduced in progenetic miniatures (β = 10.554, SE = 4.875, P = 0.038; β = 7.579, SE = 2.984, P = 0.017, respectively).

“Within each class, DNA transposons and LTR elements were both significantly reduced in progenetic miniatures (β = 10.554, SE = 4.875, P = 0.038; β = 7.579, SE = 2.984, P = 0.017, respectively)”

The quote only partly states this claim.

Compact introns showed pronounced differences across first (5′), last (3′), and middle intron positions between progenetic miniatures and nonminiatures.

“Compact introns showed pronounced differences across first (5′), last (3′), and middle intron positions”

May combine two claims.

Among ancient insertions (K2P > 20%), LTR elements showed a trend toward reduction in progenetic miniatures (β = 1.937, SE = 1.083, P = 0.084), though no other repeat types differed significantly.

“Among ancient insertions (K2P > 20%), LTR elements showed a trend toward reduction in progenetic miniatures (β = 1.937, SE = 1.083, P = 0.084), though no other repeat types differed significantly.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Median gene lengths were marginally but nonsignificantly longer in nonminiature species relative to all miniatures combined (β = 2,433.5, SE = 1,291.6, P = 0.069) and to progenetic miniatures (β = 2,302.6, SE = 1,520.5, P = 0.140).

“Median gene lengths were marginally but nonsignificantly longer in nonminiature species relative to all miniatures combined (β = 2,433.5, SE = 1,291.6, P = 0.069) and to progenetic miniatures (β = 2,302.6, SE = 1,520.5, P = 0.140; Fig. 5)”

May combine two claims.

Among intermediate divergence insertions (K2P 5 to 20%), LTR elements were significantly reduced in progenetic miniatures (β = 4.786, SE = 2.033, P = 0.025), while other repeat content was significantly elevated (β = −1.463, SE = 0.557, P = 0.014).

“Among intermediate divergence insertions (K2P 5 to 20%), LTR elements were significantly reduced in progenetic miniatures (β = 4.786, SE = 2.033, P = 0.025), while other repeat content was significantly elevated (β = −1.463, SE = 0.557, P = 0.014)”

May combine two claims.

Miniaturization evolved independently multiple times within Cypriniformes, with transitions predominantly unidirectional from nonminiature to miniature states.

“Miniaturization evolved independently multiple times within Cypriniformes, with transitions predominantly unidirectional from nonminiature to miniature states.”

May combine two claims.

Progenetic miniature origins were concentrated in the Eocene while proportioned dwarfs originated predominantly in the Miocene.

“progenetic miniature origins were concentrated in the Eocene while proportioned dwarfs originated predominantly in the Miocene”

May combine two claims.

The proportioned dwarf B. brigittae showed a TE age distribution comparable to nonminiature species, consistent with the absence of overall TE depletion in this lineage.

“In contrast, the proportioned dwarf B. brigittae showed a TE age distribution comparable to nonminiature species, consistent with the absence of overall TE depletion in this lineage.”

May combine two claims.

Intron shortening in progenetic miniatures was genome-wide, affecting first, last, and middle intron positions, and was most pronounced in compact intron size classes.

“This intron shortening was genome-wide, affecting first, last, and middle intron positions, and was most pronounced in compact intron size classes.”

Classified as probably not a substantial claim.

Three species with available genome assemblies (Xyrauchen texanus, Paramisgurnus dabryanus, Cirrhinus molitorella) were not sampled in the original 335-species molecular dating analysis.

“Three species with available genome assemblies (Xyrauchen texanus, Paramisgurnus dabryanus, Cirrhinus molitorella) were not sampled in the original 335-species molecular dating analysis.”

May combine two claims.

Intron shortening was consistently associated with progenetic miniaturization and did not accompany TE-mediated genome compaction in nonminiature lineages.

“Intron shortening was consistently associated with progenetic miniaturization and did not accompany TE-mediated genome compaction in nonminiature lineages.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Miniaturization is widespread among vertebrates.

“Miniaturization is widespread among vertebrates, yet its genomic basis remains poorly understood.”

• cites [1] J. Hanken, D. B. Wake, Miniaturization of body size: Organismal consequences and evolutionary significance. Ann. Rev. Ecol. Syst. 24, 501– 519 (1993). sourceNot checked — no full text of the source

May combine two claims.

Genome size is more conserved within lineages while body size is more evolutionarily variable, consistent with the repeated independent evolution of miniaturization.

“though the contrasting K values indicate that genome size is more conserved within lineages while body size is more evolutionarily variable, consistent with the repeated independent evolution of miniaturization.”

May combine two claims.

Progenetic miniaturization is driven by predictable structural genomic changes, revealing a fundamental link between genome architecture and developmental truncation in vertebrates.

“These findings demonstrate that progenetic miniaturization is driven by predictable structural genomic changes, revealing a fundamental link between genome architecture and developmental truncation in vertebrates.”

May combine two claims.

Progenetic miniature lineages show genome-wide intron shortening but not intron loss.

“providing evidence for genome-wide intron shortening but not intron loss in progenetic miniature lineages.”

May combine two claims.

Intron shortening of compact introns is specifically associated with progenetic miniaturization and does not accompany TE-mediated genome compaction in nonminiature lineages in Cypriniformes.

“This suggests that intron shortening of compact introns is specifically associated with progenetic miniaturization and does not accompany TE-mediated genome compaction in nonminiature lineages in Cypriniformes.”

May combine two claims.

In the progenetic miniatures examined here, early maturation is accompanied by rapid, time-compressed development, which by the same rate-based logic would favor genome reduction.

“In the progenetic miniatures examined here, however, early maturation is accompanied by rapid, time-compressed development, which by the same rate-based logic would favor genome reduction.”

Classified as probably not a substantial claim.

In progenetic miniatures specifically, developmental rate offers a plausible candidate selective pressure.

“In the progenetic miniatures specifically, developmental rate offers a plausible candidate selective pressure.”

Classified as probably not a substantial claim. May combine two claims.

Across amphibians, genome size is linked to developmental rate rather than to life-cycle mode per se: species with shorter developmental periods have smaller genomes, consistent with selection reducing genome size where rapid development is favored.

“Across amphibians, genome size is linked to developmental rate rather than to life-cycle mode per se: species with shorter developmental periods have smaller genomes, consistent with selection reducing genome size where rapid development is favored (48).”

• cites [48] H. C. Liedtke, D. J. Gower, M. Wilkinson, I. Gomez-Mestre, Macroevolutionary shift in the size of amphibian genomes and the role of life history and climate. Nat. Ecol. Evol. 2, 1792– 1799 (2018). 30250158 sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

Miniaturization is a recurrent theme across animal diversity, having evolved independently across numerous invertebrate and vertebrate lineages.

“Miniaturization, the reduction of adult body size to an extreme degree, is a recurrent theme across animal diversity, having evolved independently across numerous invertebrate and vertebrate lineages (1).”

• cites [1] J. Hanken, D. B. Wake, Miniaturization of body size: Organismal consequences and evolutionary significance. Ann. Rev. Ecol. Syst. 24, 501– 519 (1993). sourceNot checked — no full text of the source

May combine two claims.

Intron shortening in progenetic miniatures is genome-wide rather than position-specific, with the exception of single introns which did not differ significantly.

“indicating a genome-wide rather than position-specific phenomenon, with the exception of single introns which did not differ significantly between groups (SI Appendix, Figs. S14–S17 and Tables S5 and S6).”

May combine two claims.

TE depletion in progenetic miniature genomes is not confined to a single temporal class but reflects a sustained and prolonged reduction in transposition activity spanning both recent and intermediate timescales, consistent with a genome-wide and temporally extended process of repeat loss rather than a recent or episodic purging of insertions.

“Taken together, these results indicate that TE depletion in progenetic miniature genomes is not confined to a single temporal class but reflects a sustained and prolonged reduction in transposition activity spanning both recent and intermediate timescales, consistent with a genome-wide and temporally extended process of repeat loss rather than a recent or episodic purging of insertions.”

May combine two claims.

The nonrandom phylogenetic distribution of miniaturization suggests that the propensity for miniaturization is phylogenetically structured within Cypriniformes, indicating that certain lineages may possess developmental or ecological preconditions that facilitate body size reduction.

“This nonrandom phylogenetic distribution suggests that the propensity for miniaturization is phylogenetically structured within Cypriniformes, indicating that certain lineages may possess developmental or ecological preconditions that facilitate body size reduction.”

May combine two claims.

The relationship between selection for smaller cells/faster development and genome reduction is general and independent of body size, and could account for the reduced genomes of both nonminiature loaches and progenetic miniatures through distinct selective pressures acting on a shared mechanism.

“This relationship is general and independent of body size, and could account for the reduced genomes of both the nonminiature loaches and the progenetic miniatures through distinct selective pressures acting on a shared mechanism.”

May combine two claims.

The difference in frequency between the two types likely reflects greater developmental constraints on progenetic miniaturization, which requires extreme heterochronic shifts resulting in simultaneous truncation of multiple organ systems, compared to proportioned dwarfism, which may face fewer developmental and genetic constraints.

“The difference in frequency likely reflects the greater developmental constraints on progenetic miniaturization, which requires extreme heterochronic shifts resulting in the simultaneous truncation of multiple organ systems, compared to the simpler body size reduction characterizing proportioned dwarfism, which may face fewer developmental and genetic constraints (5, 14, 42).”

• cites [5] R. Britz, K. W. Conway, Danionella dracula, an escape from the cypriniform Bauplan via developmental truncation? J. Morphol. 277, 147– 166 (2016). 26589666 sourceNot checked — no full text of the source
• cites [14] R. Britz, K. W. Conway, Osteology of Paedocypris, a miniature and highly developmentally truncated fish (Teleostei: Ostariophysi: Cyprinidae). J. Morphol. 270, 389– 412 (2009). 19107939 sourceNot checked — no full text of the source
• cites [42] K. W. Conway, K. Kubicek, R. Britz, Extreme evolutionary shifts in developmental timing establish the miniature Danionella as a novel model in the neurosciences. Dev. Dyn. 250, 601– 611 (2021). 33325050 sourceNot checked — no full text of the source

May combine two claims.

Loaches along with Psilorhynchidae (torrent minnows), which also had reduced genome sizes, are predominantly benthic fishes adapted to fast-flowing, well-oxygenated streams.

“Loaches along with Psilorhynchidae (torrent minnows), which also had reduced genome sizes, are predominantly benthic fishes adapted to fast-flowing, well-oxygenated streams (49)”

• cites [49] N. K. Lujan, K. W. Conway, “ Life in the fast lane: A review of rheophily in fishes” in Extremophile Fishes: Ecology and Evolution of Teleosts in Extreme Environments, R. Riesch, M. Tobler, M. Plath, Eds. (Springer, 2015), pp. 107– 136. sourceNot checked — no full text of the source

Classified as probably not a substantial claim. May combine two claims.

Extreme body-size reduction is thought to facilitate exploitation of structurally complex, resource-limited or unstable environments and is often accompanied by fast life histories, consistent with selection for rapid development.

“Extreme body-size reduction is thought to facilitate exploitation of structurally complex, resource-limited or unstable environments (1) and is often accompanied by fast life histories, consistent with selection for rapid development.”

• cites [1] J. Hanken, D. B. Wake, Miniaturization of body size: Organismal consequences and evolutionary significance. Ann. Rev. Ecol. Syst. 24, 501– 519 (1993). sourceNot checked — no full text of the source

May combine two claims.

The preferential shortening of compact introns suggests that introns most tolerant of length reduction are the primary targets of genome streamlining, while long introns with greater regulatory content show comparatively less reduction.

“The preferential shortening of compact introns suggests that introns most tolerant of length reduction are the primary targets of genome streamlining, while long introns with greater regulatory content show comparatively less reduction.”

Classified as probably not a substantial claim.

All genomes were annotated for TEs using the same pipeline to ensure comparability across species.

“All genomes were annotated for TEs using the same pipeline to ensure comparability across species.”

May combine two claims.

The comparative genomics dataset comprised 33 high-quality reference genomes with available gene annotations, of which 31 are pseudo-chromosome-level assemblies, representing 11 cypriniform families spanning all four recognized suborders.

“We compiled a dataset of 33 high-quality reference genomes with available gene annotations, of which 31 are pseudo-chromosome-level assemblies, representing 11 cypriniform families spanning all four recognized suborders (SI Appendix, Table S17).”

May combine two claims.

One feature may be distinctive: the progenetic-miniature signature localizes to compact introns, whereas other compact-genomed cypriniforms instead shorten long introns, and pufferfish intron reduction has so far been assessed only in aggregate.

“One feature may nonetheless be distinctive: the progenetic-miniature signature localizes to compact introns, whereas other compact-genomed cypriniforms instead shorten long introns, and pufferfish intron reduction has so far been assessed only in aggregate.”

Classified as probably not a substantial claim.

The equal-rates (ER) model was selected after comparing it against symmetric (SYM) and all-rates-different (ARD) models by corrected Akaike Information Criterion (AIC).

“We selected an equal-rates (ER) model of state transitions after comparing it against symmetric (SYM) and all-rates-different (ARD) models by corrected Akaike Information Criterion (AIC).”

Classified as probably not a substantial claim.

PGLS regression models were fitted to test whether genome size differed between miniaturized and nonminiaturized lineages while accounting for phylogenetic nonindependence among species.

“To test whether genome size differed significantly between miniaturized and nonminiaturized lineages while accounting for phylogenetic nonindependence among species, we fitted PGLS regression models using the phylolm package (87).”

• cites [87] L. S. T. Ho, C. Ané, Intrinsic inference difficulties for trait evolution with Ornstein-Uhlenbeck models. Methods Ecol. Evol. 5, 1133– 1146 (2014). sourceNot checked — no full text of the source

May combine two claims.

The ARD model's fitted transition matrix was degenerate, with rates into and out of the progenetic-miniature state estimated at approximately zero, indicating nonidentifiability given the small number of progenetic miniature origins.

“Although ARD received the highest AIC weight, its fitted transition matrix was degenerate, with rates into and out of the progenetic-miniature state estimated at approximately zero, indicating nonidentifiability given the small number of progenetic miniature origins.”

Classified as probably not a substantial claim.

Comparative analyses were conducted under two complementary grouping schemes: all miniature species combined vs. nonminiatures, and progenetic miniatures vs. proportioned dwarfs vs. nonminiatures.

“All comparative analyses were conducted under two complementary grouping schemes: i) all miniature species combined (progenetic miniatures and proportioned dwarfs) vs. nonminiatures, and ii) progenetic miniatures vs. proportioned dwarfs vs. nonminiatures.”

May combine two claims.

The pruned tree comprised 309 cypriniform species, of which 12 are progenetic miniatures, 26 are proportioned dwarfs, and 271 are nonminiature species.

“The resulting pruned tree comprised 309 cypriniform species, of which 12 are progenetic miniatures, 26 are proportioned dwarfs, and 271 are nonminiature species (SI Appendix, Table S12).”

Probably not a substantial claim: may not pass S3 (load-bearing).

Estimates from k = 21 and k = 31 were strongly concordant.

“Estimates from k = 21 and k = 31 were strongly concordant”

Classified as probably not a substantial claim. May combine two claims.

Given the limited number of miniaturized species in our dataset (n = 4), we report uncorrected P-values but interpret results conservatively, emphasizing effect sizes and consistency across biologically related metrics.

“Given the limited number of miniaturized species in our dataset (n = 4), we report uncorrected P-values but interpret results conservatively, emphasizing effect sizes and consistency across biologically related metrics.”

May combine two claims.

Genome compaction in progenetic miniatures involves compositional remodeling rather than uniform repeat depletion, with simple repeats significantly enriched relative to nonminiatures, indicating mechanistically specific streamlining rather than a general suppression of all repetitive elements.

“Genome compaction in progenetic miniatures involves compositional remodeling rather than uniform repeat depletion, with simple repeats significantly enriched relative to nonminiatures, indicating mechanistically specific streamlining rather than a general suppression of all repetitive elements.”

Classified as probably not a substantial claim.

The resulting pruned phylogeny with 33 tips retained the divergence times and branch length estimates from the full molecular dating analysis.

“The resulting pruned phylogeny with 33 tips retained the divergence times and branch length estimates from the full molecular dating analysis.”

May combine two claims.

This sampling encompassed all four recognized genera of progenetic miniatures and nearly all known genera of cypriniform proportioned dwarfs.

“This sampling encompassed all four recognized genera of progenetic miniatures and nearly all known genera of cypriniform proportioned dwarfs (SI Appendix, Table S13).”

Classified as probably not a substantial claim.

To account for divergence-time uncertainty, ancestral state reconstruction was repeated across 100 trees randomly sampled from the post-burn-in BEAST posterior, performing 1,000 stochastic maps on each under the same ER model.

“To ensure that the inferred numbers and ages of miniaturization origins reflected divergence-time uncertainty rather than resting on a single chronogram, we repeated this analysis across 100 trees randomly sampled from the post–burn-in BEAST posterior, performing 1,000 stochastic maps on each under the same ER model (100,000 maps in total).”

Probably not a substantial claim: may not pass S3 (load-bearing).

Phylogenetic signal for genome size and body size was quantified using Pagel's λ and Blomberg's K before formal comparative tests.

“Before conducting formal comparative tests, we quantified phylogenetic signal for both genome size and body size to assess the degree to which trait variation reflects shared evolutionary history. Two complementary metrics were calculated using the phylosig function in phytools: Pagel’s λ (83) and Blomberg’s K (84).”

• cites [83] M. Pagel, Inferring the historical patterns of biological evolution. Nature 401, 877– 884 (1999). 10553904 sourceNot checked — no full text of the source
• cites [84] S. P. Blomberg, T. Garland, A. R. Ives, Testing for phylogenetic signal in comparative data: Behavioral traits are more labile. Evolution 57, 717– 745 (2003). 12778543 sourceNot checked — no full text of the source