Claim

Whole-genome data from 101 museum specimens indicate an approximately 24.6% reduction in genome-wide heterozygosity in the moss carder bumblebee across Britain between 1894 and 2019.

Type QUANTITATIVE · truth-evaluable: yes · status at snapshot: ACTIVE · created seq 18460 · qualifiers {"population":"Bombus muscorum museum specimens from Britain and Ireland, collected 1894–2019; Britain-wide heterozygosity comparison."}

Referenced 120 times: checked 2, looked up by assistants 0, viewed 83, shared 35. A count of attention, not evidence.

Topics

Biology · 1efd24fe Wildlife · 1efd24fe

Assessment

Supported

Score: 0.9487 under ledger-default@0.3.0 at snapshot 27745

2 of 4 review checks done · 1 counted · 1 by the author only

2 independent evidence lineages · review checks 1 of 4 · stability HIGH

Main unresolved issue: 6 counted evidence items have no independence review; repeats of one origin may be counted as several coverage:915dbabf-a8b4-8c5f-87ea-79be72bb9ba9

Not yet independently audited.Evidence reviewed so far supports this claim, but only 1 of 4 review checks has been done.Every quoted passage was confirmed on the page when Galedra fetched it.

Why?

Strongest counted support: The abstract reports an approximately 24.6% reduction in genome-wide heterozygosity across Britain. weight 2.000000 evidence

Suppressed as dependent: The excerpt directly reports 101 museum specimens, 1894–2019, and an approximately 24.6% Britain-wide heterozygosity reduction.

Review gaps: qualifiers reviewed, opposing search done, independence reviewed

What would most change this: One independent, direct measurement that contradicts this claim would move it from Supported to Leans supported.

Hide calculation

0.9487 under ledger-default@0.3.0 at snapshot 27745 · state Supported · Review checks: 1 of 4 · stability HIGH · 6 sources, 2 independent lineages

Model ledger-default@0.3.0 (the default model, not the answer) · snapshot 27745 · trace sha256:1b9c36c56e8de67ecdba5e98cd0031a4122c86060e4bd2ea8bffd3f75c0f70af

Last changed at entry seq 25902; nothing logged since has borne on this claim.

How the number was reached

Each counted link is weighed by multiplying the factors the model declares; a factor it does not declare is not shown. Every factor name below links to what that number means.

Link	Working	Weight	Counted as
8d991d4b support	relevance DIRECT 2.0 × observation MEASUREMENT 1.0 × interpretation 0 steps, 1 − 0.15 × 0 1.000000 × authenticity UNVERIFIED 1.0 × extraction UNVERIFIED 1.0 × provenance INDEPENDENT 1.0 × edition NAMED_OR_UNRELATED 1	2.000000	2.000000
429bdc9c support	relevance STRONG 1.2 × observation DIRECT_TEXT 0.9 × interpretation 1 step, 1 − 0.15 × 1 0.850000 × authenticity UNVERIFIED 1.0 × extraction UNVERIFIED 1.0 × provenance INDEPENDENT 1.0 × edition NAMED_OR_UNRELATED 1	0.918000	0.918000
37a7a76d qualify	relevance DIRECT 2.0 × observation MEASUREMENT 1.0 × interpretation 0 steps, 1 − 0.15 × 0 1.000000 × authenticity UNVERIFIED 1.0 × extraction UNVERIFIED 1.0 × provenance INDEPENDENT 1.0 × edition NAMED_OR_UNRELATED 1	2.000000	0.000000 (non directional)
e4bfbb5e qualify	relevance DIRECT 2.0 × observation MEASUREMENT 1.0 × interpretation 0 steps, 1 − 0.15 × 0 1.000000 × authenticity UNVERIFIED 1.0 × extraction UNVERIFIED 1.0 × provenance INDEPENDENT 1.0 × edition NAMED_OR_UNRELATED 1	2.000000	0.000000 (non directional)
4a91b188 qualify	relevance DIRECT 2.0 × observation MEASUREMENT 1.0 × interpretation 0 steps, 1 − 0.15 × 0 1.000000 × authenticity UNVERIFIED 1.0 × extraction UNVERIFIED 1.0 × provenance INDEPENDENT 1.0 × edition NAMED_OR_UNRELATED 1	2.000000	0.000000 (non directional)
65f8e3e8 support	relevance DIRECT 2.0 × observation DIRECT_TEXT 0.9 × interpretation 0 steps, 1 − 0.15 × 0 1.000000 × authenticity UNVERIFIED 1.0 × extraction UNVERIFIED 1.0 × provenance INDEPENDENT 1.0 × edition NAMED_OR_UNRELATED 1	1.800000	0.000000 (dependent strongest only, kept 8d991d4b)

prior 0.50 → log-odds 0.000000 + 2.918000 (the counted weights) = 2.918000 → probability 0.9487

Under neighbouring settings of the same model: 0.8852 to 0.9780, a spread of 0.0928.

Half-even rounding, six places for weights and four for the probability. The same inputs under the same model reproduce this exactly; that is what the trace hash above is for. How a score is worked out explains every factor, why it is there, and what the model sets it to.

Your view

Registered views

Nobody has registered a view yet.

Registered views are personal belief, not evidence: they never change Galedra's assessment. Affiliations are self-declared and shown only for groups of 5 or more.

Checked as part of

Statements this claim was broken out of. The claim is scored on its own; a statement's reading only counts its claims.

“Whole-genome data from 101 museum specimens indicate an approximately 24.6% reduction in genome-wide heterozygosity in the moss carder bumblebee across...” · 1 claim · 29 September 2026
“Whole-genome data from 101 museum specimens of the moss carder bumblebee collected across Britain and Ireland from 1894 to 2019 showed a 24.6% reduction in...” · 2 claims · 29 September 2026

Evidence for

The abstract reports an approximately 24.6% reduction in genome-wide heterozygosity across Britain.

From Museum specimens reveal the genomic consequences of long-term population decline in an insect pollinator Read 2026-09-29 Relevance DIRECT Steps 0 Counted
The study commentary reports about a 25% reduction in genome-wide genetic diversity and progressive twentieth-century heterozygosity decline in the moss carder bumblebee.

From A century of genetic erosion in a British bumblebee – a new study just published Read 2026-09-29 Relevance STRONG Steps 1 Counted

Author commentary about the same study; corroborating context, not an independent research lineage.
The excerpt directly reports 101 museum specimens, 1894–2019, and an approximately 24.6% Britain-wide heterozygosity reduction.

From Museum specimens reveal the genomic consequences of long-term population decline in an insect pollinator Read 2026-09-29 Relevance DIRECT Steps 0 Counted

Evidence against

None.

Qualifications

The estimate is based on a museum-derived sample of more than 100 specimens from five UK institutions collected across 1890–2019, not a census of the British population.

From Threatened British bumblebee populations face severe genetic declines Read 2026-09-29 Relevance DIRECT Steps 0 Counted
The heterozygosity decline is Britain-wide, while the accompanying inbreeding signal is specifically emphasized for England and Wales and is not uniform across Britain.

From Threatened British bumblebee populations face severe genetic declines Read 2026-09-29 Relevance DIRECT Steps 0 Counted
Genome-based checking found 29 initially identified museum specimens were close relatives, an important sampling and denominator qualification.

From Threatened British bumblebee populations face severe genetic declines Read 2026-09-29 Relevance DIRECT Steps 0 Counted

Suppressed as dependent

Evidence	Group	Kept instead
54dd1cf5		8d991d4b

Inferences

Concluded from

None.

Used as a premise in

None.

An inference is interpretation, not evidence: it never changes the assessment of its conclusion. Each premise is a claim with its own evidence.

Threads

None. Threads are for disagreements about how a determination was made — a statement whose figures are not in the passage it rests on, two sources that may share an origin. Something about the world belongs in the evidence above.

Claim edges

None. Edges are stored and displayed; v0.1 does not propagate probability across them.

Review checklist

Review checks: 1 of 4

2 checks by this claim's own author, alongside the independent review above. 1 QUALIFIER CHECK · 1 EVIDENCE VERIFICATION. A check by the person who recorded a claim does not raise its review coverage.

Check	Done	By
qualifiers reviewed	no
opposing search done	no
independence reviewed	no
primary source reviewed	yes	8d991d4b, 65f8e3e8

Summary

Supported. The main support is: The abstract reports an approximately 24.6% reduction in genome-wide heterozygosity across Britain. 826a1721

1 further item repeats the same origin and is not independent evidence. 54dd1cf5

Qualifier: Genome-based checking found 29 initially identified museum specimens were close relatives, an important sampling and denominator qualification. 72858e8d

Qualifier: The heterozygosity decline is Britain-wide, while the accompanying inbreeding signal is specifically emphasized for England and Wales and is not uniform across Britain. c26a88db

Qualifier: The estimate is based on a museum-derived sample of more than 100 specimens from five UK institutions collected across 1890–2019, not a census of the British population. 786df997

Review checks: 1 of 4. coverage:915dbabf-a8b4-8c5f-87ea-79be72bb9ba9

Generated by stub-v0.1; every sentence cites graph ids.

Contribution history

seq	event	detail
18460	APPENDED
18461	ACCEPT	AUTOMATIC_AFTER_VALIDATION
18472	LINK_EVIDENCE	by 1efd24fe (accepted)
18524	LINK_EVIDENCE	by 1efd24fe (accepted)
24711	TASK_RESULT	by 1efd24fe (accepted)
25901	TASK_RESULT	by 1efd24fe (accepted)

Score trace

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  "contested": false,
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