NotablePeer-reviewed
ByAline P. M. Medeiros, Melissa Rincón-Sandoval, Aaron M. Davis, Aintzane Santaquiteria, Christine E. Thacker, Joshua Egan and 2 others
Scripps Institution of Oceanography · University of Oklahoma · Australian Institute of Tropical Health and Medicine · George Washington University and 4 more
Tropical rivers in Australia and New Guinea (Sahul) provide a rare natural experiment in vertebrate evolution: Unlike other continental systems, their freshwater ichthyofaunas are composed almost entirely of marine-derived lineages rather than primary freshwater fishes.
Every metric behind this entry is listed, with its source, under Sources and data below.
Filed underFish biology, ecology, and behavior, Paleontology and Evolutionary Biology, Evolution and Paleontology Studies
| Term | Score | Weight | Points |
|---|---|---|---|
| EvidenceHow established and verifiable the result is. | 86 | × 0.25 | 21.6 |
| ImpactHow much the result matters, judged field-relative and by current momentum. | 51 | × 0.25 | 12.7 |
| NoveltyHow genuinely new the result is, and how fast-moving. | 68 | × 0.50 | 33.8 |
| Weighted pillars | 68.0 | ||
| Frontier recency0 months since publication | × 0.99 | ||
| IntegrityNot retracted | × 1 | ||
| Frontier Score | 68 |
Every sub-metric, traced to its source
| Sub-metric | Raw value | 0 to 100 | Weight | Points | Source |
|---|---|---|---|---|---|
| Peer review & venueWhether the work has cleared peer review, and how selective its venue is. Peer review is necessary but not sufficient: before citations accrue, a fresh result in one of the five general flagships (Nature, Science, Cell, NEJM, the Lancet) is a stronger evidence signal than one in a selective specialist or society journal, which in turn outranks one in a legitimate but very high-volume mega-journal, and any of them outranks a preprint that has not been reviewed at all.Maps to 0 to 100: Peer-reviewed article graded by venue tier: flagship journal (Nature, Science, Cell, NEJM, the Lancet) 100; selective journal (the specialist journals of those families, JAMA, PNAS, Physical Review Letters and X) 90; high-volume mega-journal (Nature Communications, Science Advances) 78. Review 90, book 70, dataset 60, preprint 45, other 55. | Peer-reviewed, selective journal | 90 | 0.30 | 27.0 | OpenAlex type / primary_location / source |
| CorroborationIndependent corroboration that the result is real and being taken up, read as the BREADTH of agreement rather than the size of the citation pile. Counts how many of the five independent citation indices (OpenAlex, Crossref, Semantic Scholar, OpenCitations, Europe PMC) report the work at all, plus orthogonal, non-citation lines of corroboration: entry into the encyclopedia, registered clinical trials, released datasets or software, public funding on record, and technical-community discussion. Citation MAGNITUDE is deliberately judged under Impact, not here, so Evidence and Impact measure genuinely different things instead of both rewarding the same citation pile twice.Maps to 0 to 100: Starts at 28 and rises with each of the five independent citation indices that agree the work is cited (+9 each) and each orthogonal non-citation corroboration line (+6 each: Wikipedia, clinical trials, open datasets or software, public funding, community discussion). Capped at 100. | 4 of 5 citation indices agree | 64 | 0.30 | 19.2 | OpenAlex, Crossref, Semantic Scholar, OpenCitations, Europe PMC, DataCite, NIH RePORTER, Wikipedia, Hacker News count of agreeing indices + orthogonal reach |
| VerifiabilityHow openly the result can be read, reused, and reproduced. Rewards open access, a permissive reuse license (CC-BY/CC0), a green repository copy anyone can archive, openly minable full text, and released datasets or software a reader can actually run. Cross-checked across OpenAlex, Unpaywall, Europe PMC, and DataCite.Maps to 0 to 100: Closed 45; open access 80+; a permissive CC license 100; a repository copy, open full text, or a released dataset/software artifact each raise the floor. | Open access (hybrid), CC-BY-NC-ND | 100 | 0.20 | 20.0 | OpenAlex, Unpaywall, Europe PMC, DataCite is_oa / license / has_repository_copy / open datasets |
| IntegrityRetraction and post-publication correction status. A retracted result is not evidence of anything and collapses the whole Frontier Score; a correction or expression of concern is a softer flag. Read across OpenAlex and Crossref (both update-to and updated-by notices).Maps to 0 to 100: Clean 100; a correction or expression of concern 75; retracted 0. Flagged if OpenAlex OR Crossref records the notice. | No retraction or concern on record | 100 | 0.20 | 20.0 | OpenAlex, Crossref is_retracted / update-to / updated-by |
| Sub-metric | Raw value | 0 to 100 | Weight | Points | Source |
|---|---|---|---|---|---|
| Field-normalized impactImpact relative to the world average for the same field, year, and type, so a small field and a large field are judged fairly. Triangulates three independent field-normalized measures: OpenAlex's Field-Weighted Citation Impact, its citation percentile within the exact field-and-year cohort, and the NIH iCite Relative Citation Ratio. 1.0x is average; the percentile is the share of same-field, same-year work it out-cites.Maps to 0 to 100: Each ratio (1.0 = field average) maps 1.0 to 50, 3.0 to 75, 9.0 to 90; the field+year percentile maps directly (top 1% -> ~99). The available measures are averaged. Falls back to a saturating citation count when none is available yet. | top 10% of field-year vs field | 90 | 0.45 | 40.5 | OpenAlex, NIH iCite fwci / citation_normalized_percentile / relative_citation_ratio |
| Influential citationsCitations that genuinely build on the work rather than mention it in passing (Semantic Scholar's influential-citation measure). A sharper signal of real impact than a raw count.Maps to 0 to 100: Saturating: 15 influential citations maps to 50. Falls back to a fraction of consensus citations when unavailable. | Not yet available | n/a | redistributed | 0.0 | Semantic Scholar influentialCitationCount |
| Citation velocityCitations received in the trailing twelve months, judged as a rate rather than a lifetime total. Momentum is what a frontier index cares about: a result being taken up fast right now is landing, whether its lifetime pile is large or still small. Where an expected field citation rate is known, the momentum is also read relative to it, so a fast-moving result in a quiet field is not overlooked.Maps to 0 to 100: Saturating: 30 citations in the last twelve months maps to 50. When NIH iCite provides the field's expected rate, this is blended evenly with the ratio of observed to expected momentum. | 0 in last 12 months | 0 | 0.35 | 0.0 | OpenAlex, NIH iCite counts_by_year / field_citation_rate |
| Sub-metric | Raw value | 0 to 100 | Weight | Points | Source |
|---|---|---|---|---|---|
| Conceptual noveltyHow genuinely new the contribution is, measured at publication from the work's OWN content, not its date: how atypical its combination of research areas is versus all prior work, and whether it builds on a broad, deep base rather than only the newest papers in a fast-moving area. This is what separates a real advance from a recent-but-commodity result, and it needs no forward citations, so it is stable for brand-new work. An honestly noisy proxy (even state-of-the-art novelty measures agree only moderately with expert judgment), so it carries bounded weight and never drives the ranking alone.Maps to 0 to 100: Blends two publication-time signals, each 0-100: an atypical-combination score (how unusual the pairing of the work's research topics is versus the prior literature, by pointwise mutual information) and a foundational-reach score (median age and depth of the work's references). The stronger signal weighs 0.62, the weaker 0.38. When neither is measurable (a work too thin in topics or references), the pillar renormalizes over its recency signals instead. | Fish biology, ecology, and behavior x Evolution and Paleontology Studies (3,425 prior works made this pairing); builds on refs a median 12.0y deep | 46 | 0.45 | 20.8 | OpenAlex topics + referenced_works (publication-time) |
| RecencyHow recently the work appeared. The frontier is now, so newer scores higher.Maps to 0 to 100: Exponential decay with a 12-month half-life from the publication date. | This month | 99 | 0.30 | 29.7 | OpenAlex publication_date |
| Attention accelerationWhether attention is rising: citations in the latest full year versus the year before. Accelerating interest signals an active, opening frontier.Maps to 0 to 100: Latest/prior-year ratio: 1x maps to 50, 2x to 75, 4x to 100. Unknown is neutral. | Not enough history | 50 | 0.10 | 5.0 | OpenAlex counts_by_year |
| Edge of reviewPreprints and brand-new work sit ahead of the peer-review process. That earns novelty here (while it is discounted under Evidence), because it is where the frontier forms first.Maps to 0 to 100: Preprint 95, article <6 months 80, article <18 months 65, else 45. | Peer-reviewed record | 80 | 0.15 | 12.0 | OpenAlex type / publication_date |
Live preview
<a href="https://frontierresearch.co/breakthroughs/repeated-marine-to-freshwater-fish-transitions-reveal-pa-w7214940692?utm_source=badge&utm_medium=badge&utm_campaign=author-kit"><img src="https://frontierresearch.co/api/badge/W7214940692.svg" alt="Frontier Score for this paper" height="20"></a>For a lab or personal website, a CV page, or anywhere that takes HTML.
The number is live. The badge is drawn from the same signals as this page, so it never shows a score the entry does not. Every entry is re-checked weekly against the same public sources, and a result's standing eases as it ages, so the active edge of the field stays on top. How scoring works
Something wrong or out of date? Write to hello@frontierresearch.co and the entry will be corrected.
Climate & Environment · Notable
E 88I 41N 85Sep 28, 2026
Climate & Environment · Notable
E 92I 40N 79Sep 23, 2026
Climate & Environment · Notable
E 91I 48N 69Sep 23, 2026
Back to the Frontier Index, or browse every breakthrough by date.
The Frontier Brief
Every Monday, the new Climate & Environment entries in the index, each with its score and a one-line read on why it matters, then the week's best from the rest of the frontier. What you get
Prefer a feed reader? Follow Climate & Environment by RSS