Evidence map›Paper›PMID 33558231›Full record

ArticleProceedings of the National Academy of Sciences of the United States of America2021

A global phylogeny of turtles reveals a burst of climate-associated diversification on continental margins.

Robert C Thomson, Phillip Q Spinks, H Bradley Shaffer

Abstract read
In one paragraph

Article in Proceedings of the National Academy of Sciences of the United States of America, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 76 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
76citing papers in PubMed, 1 pooled it
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

76 citing papers in PubMed, 1 synthesis or guideline pooled it.

  1. Pooled it
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  8. Regulatory diversification of conservedZoological research · 2026
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  15. Evolvability in vertebrate segmentation.Seminars in cell & developmental biology · 2025
    Review
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16 more citing papers are in PubMed but not listed here.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

3 authors.

Robert C ThomsonSchool of Life Sciences, University of Hawai'i, Honolulu, HI 96822; thomsonr@hawaii.edu.ORCID 0000-0001-8006-1484
Phillip Q SpinksDepartment of Ecology and Evolutionary Biology, University of California, Los Angeles, CA 90095.ORCID 0000-0002-3611-6051
H Bradley ShafferDepartment of Ecology and Evolutionary Biology, University of California, Los Angeles, CA 90095.ORCID 0000-0002-5795-9242

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Living turtles are characterized by extraordinarily low species diversity given their age. The clade's extensive fossil record indicates that climate and biogeography may have played important roles in determining their diversity. We investigated this hypothesis by collecting a molecular dataset for 591 individual turtles that, together, represent 80% of all turtle species, including representatives of all families and 98% of genera, and used it to jointly estimate phylogeny and divergence times. We found that the turtle tree is characterized by relatively constant diversification (speciation minus extinction) punctuated by a single threefold increase. We also found that this shift is temporally and geographically associated with newly emerged continental margins that appeared during the Eocene-Oligocene transition about 30 million years before present. In apparent contrast, the fossil record from this time period contains evidence for a major, but regional, extinction event. These seemingly discordant findings appear to be driven by a common global process: global cooling and drying at the time of the Eocene-Oligocene transition. This climatic shift led to aridification that drove extinctions in important fossil-bearing areas, while simultaneously exposing new continental margin habitat that subsequently allowed for a burst of speciation associated with these newly exploitable ecological opportunities.

Indexed as

ClimateEcosystemGenetic SpeciationPhylogenyAnimalsEvolution, MolecularTurtlesdivergence time estimationGeoSSEglobal climate changeHiSSEturtle tree of life

Identifiers

PMID33558231
PMCPMC7896334

What OpenQuestion holds

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Read underepoch 390

Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.