The DOI matches its Crossref record; 76 of the 78 references it cites were found in a registry or an index; 2 of the 27 sources its claims cite were checked for support.
Clades reach highest morphological disparity early in their evolution
Open accessAbstract
There are few putative macroevolutionary trends or rules that withstand scrutiny. Here, we test and verify the purported tendency for animal clades to reach their maximum morphological variety relatively early in their evolutionary histories (early high disparity). We present a meta-analysis of 98 metazoan clades radiating throughout the Phanerozoic. The disparity profiles of groups through time are summarized in terms of their center of gravity (CG), with values above and below 0.50 indicating top- and bottom-heaviness, respectively. Clades that terminate at one of the “big five” mass extinction events tend to have truncated trajectories, with a significantly top-heavy CG distribution overall. The remaining 63 clades show the opposite tendency, with a significantly bottom-heavy mean CG (relatively early high disparity). Resampling tests are used to identify groups with a CG significantly above or below 0.50; clades not terminating at a mass extinction are three times more likely to be significantly bottom-heavy than top-heavy. Overall, there is no clear temporal trend in disparity profile shapes from the Cambrian to the Recent, and early high disparity is the predominant pattern throughout the Phanerozoic. Our results do not allow us to distinguish between ecological and developmental explanations for this phenomenon. To the extent that ecology has a role, however, the paucity of bottom-heavy clades radiating in the immediate wake of mass extinctions suggests that early high disparity more probably results from the evolution of key apomorphies at the base of clades rather than from physical drivers or catastrophic ecospace clearing.
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Claims the paper makes
15 Own result · 14 Not checked yet · 6 Own interpretation · 3 Own method · 3 No basis given · 1 Partly supported · 1 Not supported · accuracy not yet measured
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Likelihood ratio tests also confirmed that the relative frequencies of top-and bottom-heavy clades terminating at mass extinctions and at other times were different, whether including all clades (G = 7.648, P = 0.006) or only those with significant skew (G = 13.022,P < 0.001).”
§ Clades reach highest morphological disparity early in their evolution > Results and Discussion
boostedcorrelational- Asserted: passes — The authors put it forward as true.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The only temporal pattern in disparity profile shapes detected in our data was the significant tendency toward top-heaviness in those clades terminating coincident with a mass extinction [which predominantly result from physical drivers (59)].”
§ Clades reach highest morphological disparity early in their evolution > Why Do Clades Have Early High Disparity?
plaincorrelational- Asserted: passes — The authors put it forward as true.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Over half of our study clades had disparity profiles that were neither significantly top-nor bottom-heavy.”
§ Clades reach highest morphological disparity early in their evolution > Results and Discussion
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The remaining 63 clades show the opposite tendency, with a significantly bottom-heavy mean CG (relatively early high disparity).”
- Also stated in: § Results and Discussion · plain
“Therefore, clades that do not terminate at a mass extinction do indeed tend to reach their highest levels of disparity relatively early in their evolutionary histories (20).”
- Also stated in: § Results and Discussion · plain
“Of these, the proportion (two-thirds) that were either significantly bottom-heavy or showed early saturation (two mutually compatible conceptions of early high disparity) was significantly greater than the proportion that were either significantly top-heavy or showed late saturation (late high disparity) (two-sample test for equality of proportions; χ 2 = 4.613, P = 0.016).”
plaincorrelational- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Rests on an assumption: The 98 sampled clades are representative of metazoan clades across the Phanerozoic.
- Rests on an assumption: The 63 clades not terminating at a mass extinction were free-evolving and not otherwise truncated.
- Also stated in: § Results and Discussion · plain
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“For 29 of the 54 symmetrical groups, we were unable to reject this null.”
§ Clades reach highest morphological disparity early in their evolution > Results and Discussion
plain- Asserted: passes — The authors put it forward as true.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“However, comparison across four time bins [Early Paleozoic (Cambrian/ Ordovician), Late Paleozoic, Mesozoic, and Cenozoic] revealed no significant differences in the frequencies (log likelihood ratio test; G = 2.298, P = 0.513).”
- Also stated in: § Results and Discussion · plain
“Again, there were no significant differences in the relative frequencies of significantly top-and bottom-heavy clades across the four time bins (G = 3.558, P = 0.313).”
§ Clades reach highest morphological disparity early in their evolution > Results and Discussion
plain- Asserted: passes — The authors put it forward as true.
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- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
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- Also stated in: § Results and Discussion · plain
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Overall, there is no clear temporal trend in disparity profile shapes from the Cambrian to the Recent”
- Also stated in: § Results and Discussion · plain
“Finally, a plot of clade CG against the time of clade origin revealed no systemic trends throughout the Phanerozoic (Fig. 2).”
plain- Asserted: passes — The authors put it forward as true.
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- Based: passes — The paper gives a reason why it holds.
- Also stated in: § Results and Discussion · plain
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Resampling tests are used to identify groups with a CG significantly above or below 0.50; clades not terminating at a mass extinction are three times more likely to be significantly bottomheavy than top-heavy.”
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“early high disparity is the predominant pattern throughout the Phanerozoic.”
- Also stated in: § Results and Discussion · plain
“Moreover, this tendency occurs throughout the Phanerozoic.”
- Also stated in: § Why Do Clades Have Early High Disparity? · hedged
“Moreover, it seems to apply throughout the Phanerozoic, and not merely at times of global diversification (e.g., the early Paleozoic).”
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Rests on an assumption: The 98 sampled clades are representative of metazoan clades across the Phanerozoic.
- Also stated in: § Results and Discussion · plain
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Although clade disparity profiles had a mean CG indistinguishable from 0.5, there was a marked and significant difference in CG between those clades terminating coincident with a mass extinction event and those becoming extinct at other times (Fig. 3).”
§ Clades reach highest morphological disparity early in their evolution > Results and Discussion
plaincorrelational- Asserted: passes — The authors put it forward as true.
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None of the sources cited for this claim have been checked yet.
In the paper
“Several of the analyses that originally spurred the debate (10,(21)(22)(23)35) used discrete character matrices to compare anatomically very disparate forms.”
§ Clades reach highest morphological disparity early in their evolution > macroevolution | morphological disparity | morphospace | clade shape |
What the sources say
plain- Asserted: passes — The authors put it forward as true.
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None of the sources cited for this claim have been checked yet.
In the paper
“For diversity through time, random birth/death models with constant parameters predict that the average clade shape should be symmetrical (31,48).”
§ Clades reach highest morphological disparity early in their evolution > Results and Discussion
plaindirect- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
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A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Late saturation is much less remarkable, because clades have already undergone radiation and diversification and had almost the entirety of their histories in which to colonize the extremities of their morphospaces.”
§ Clades reach highest morphological disparity early in their evolution > Results and Discussion
plaindirect- Asserted: passes — The authors put it forward as true.
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- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
In the paper
“Where discrete and continuous character data have been compared for the same sets of taxa (39), relative estimates of disparity have been similar.”
§ Clades reach highest morphological disparity early in their evolution > macroevolution | morphological disparity | morphospace | clade shape |
What the sources say
- Not checked yetcites [39] source
plain- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
In the paper
“Therefore, if a clade follows a homogeneous birth-death model with characters evolving in a Brownian fashion, some top-heaviness would be expected (41).”
§ Clades reach highest morphological disparity early in their evolution > Results and Discussion
What the sources say
- Not checked yetcites [41]
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“We stress that ecological and developmental explanations for early high disparity are not mutually exclusive; neither do our results allow us to distinguish between them.”
§ Clades reach highest morphological disparity early in their evolution > Why Do Clades Have Early High Disparity?
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The absence of any systemic trends in clade disparity patterns through time, or of any increased propensity for early high disparity in clades radiating in the immediate wake of mass extinctions (Dataset S1) suggest that if ecological mechanisms have a role, then this is more likely to be mediated via key innovations (which can evolve at any time) and the opening up of new adaptive zones rather th”
§ Clades reach highest morphological disparity early in their evolution > Why Do Clades Have Early High Disparity?
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Rests on an assumption: Key innovations can arise at any time.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Our results do not allow us to distinguish between ecological and developmental explanations for this phenomenon.”
- Also stated in: § Why Do Clades Have Early High Disparity? · plain
“We stress that ecological and developmental explanations for early high disparity are not mutually exclusive; neither do our results allow us to distinguish between them.”
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Also stated in: § Why Do Clades Have Early High Disparity? · plain
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“Unfortunately, it is impossible to interpret published case studies meta-analytically for several reasons.”
§ Clades reach highest morphological disparity early in their evolution > macroevolution | morphological disparity | morphospace | clade shape |
plain- Asserted: passes — The authors put it forward as true.
- Checkable: unclear — It is unclear whether it could be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- It may state two separate claims as one. 18
- Probably not a substantial claim. 14
At least one cited source doesn’t support this claim or points to a different paper, and none confirmed it — see the verdicts below.
In the paper
“Moreover, only one of these studies (44) focused on extinction selectivity per se; all others investigated the subsequent evolution of extinction survivors.”
§ Clades reach highest morphological disparity early in their evolution > macroevolution | morphological disparity | morphospace | clade shape |
What the sources say
- Disputedcites [44] sourceExperimental — accuracy not yet measured
The cited study does not focus on extinction selectivity. Its Abstract and methods description say it measures changes in dinosaur morphological disparity during the final stages of the Cretaceous, before their extinction, rather than comparing which groups survived the extinction. (LLM, conf=0.84)
Checked by a reasoning model — may be wrong.
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Disputed
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“Early high patterns inevitably imply an unsampled period of cladogenesis (or the existence of ghost ranges) at the base of the clade, but this either occurs too fast for the available stratigraphic resolution or is not fossilized (11,50).”
§ Clades reach highest morphological disparity early in their evolution > Results and Discussion
What the sources say
- Not checked yetcites [11] source
- Partly supportedcites [50] sourceExperimental — accuracy not yet measured
The Implications (p. 11) and Conclusions (p. 17) support unpreserved Precambrian lineages and cladogenesis preceding the early Cambrian increase in disparity. They do not establish that cladogenesis occurred too fast for stratigraphic resolution; Implications treats its rate as a separate question. (LLM, conf=0.86)
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Time-averaged indices masked some apparent differences in clade disparity profiles within and between eras; most notably, there were more bottom-heavy (CG <0.5) clades in the Late Paleozoic than top-heavy (CG >0.5) clades, with the opposite pattern in the Mesozoic.”
§ Clades reach highest morphological disparity early in their evolution > Results and Discussion
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“These extant clades (truncated by the present) had a median CG significantly greater than 0.500 (V = 1,150, P < 0.001) but indistinguishable from that for fossil clades terminating at a mass extinction (W = 924, P = 0.980).”
§ Clades reach highest morphological disparity early in their evolution > Results and Discussion
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Although late saturation was observed in 32 symmetrical clades, 12 of these also ended at a mass extinction (and were therefore likely to have been prematurely truncated).”
§ Clades reach highest morphological disparity early in their evolution > Results and Discussion
hedgedcorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Across our sample of 98 clades (including those terminating coincident with a mass extinction), we found a mean disparity profile of CG of 0.495, with a median CG (0.501) indistinguishable from 0.5 (V = 2,429, P = 0.992).”
§ Clades reach highest morphological disparity early in their evolution > Results and Discussion
plain- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Clades that terminate at one of the”
- Also stated in: § Results and Discussion · plain
“By contrast, the 35 clades ending at mass extinctions had a mean CG significantly greater than 0.500 (t = 3.901, P < 0.001).”
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Also stated in: § Results and Discussion · plain
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Extant clades are more likely to have”
§ Clades reach highest morphological disparity early in their evolution > macroevolution | morphological disparity | morphospace | clade shape |
hedgeddirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
In the paper
“New species can only arise from the fission of existing ones (clades initially diversify from a single species and therefore a single point in morphospace), whereas extinctions can be random with respect to this same tree (34).”
§ Clades reach highest morphological disparity early in their evolution > Results and Discussion
What the sources say
- Not checked yetcites [34] source
plain- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
None of the sources cited for this claim have been checked yet.
In the paper
“Second, the manner in which these data have been analyzed is equally variable, although most studies implement some form of data reduction and ordination (10,12).”
§ Clades reach highest morphological disparity early in their evolution > macroevolution | morphological disparity | morphospace | clade shape |
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.
In the paper
“Third, there are many possible indices of morphological disparity, and these are known to describe different aspects of morphospace occupation (34).”
§ Clades reach highest morphological disparity early in their evolution > macroevolution | morphological disparity | morphospace | clade shape |
What the sources say
- Not checked yetcites [34] source
boosted- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.
In the paper
“Mass extinctions have undoubtedly influenced the manner in which clades have explored morphospaces (42), but this phenomenon received little”
§ Clades reach highest morphological disparity early in their evolution > macroevolution | morphological disparity | morphospace | clade shape |
What the sources say
- Not checked yetcites [42] source
boosteddirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“First, the type of data used is highly variable (outlines, landmarks, and discrete characters), as is the information that these data are intended to convey (shape, form, or homologous characters of the entire organism or of particular organ systems).”
§ Clades reach highest morphological disparity early in their evolution > macroevolution | morphological disparity | morphospace | clade shape |
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. It may state two separate claims as one.
None of the sources cited for this claim have been checked yet.
In the paper
“More generally it is likely that global shifts in climate, sea level, and ocean chemistry [coupled with the elevated rates of extinction and turnover that these phenomena engender (56-58)] affected the availability of ecospace throughout the Phanerozoic.”
§ Clades reach highest morphological disparity early in their evolution > Why Do Clades Have Early High Disparity?
What the sources say
hedgeddirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“We avoided taxonomically overlapping cases or datasets obviously derivative of others.”
§ Clades reach highest morphological disparity early in their evolution > Materials and Methods
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim.
In the paper
“which predominantly result from physical drivers (59)”
§ Clades reach highest morphological disparity early in their evolution > Why Do Clades Have Early High Disparity?
What the sources say
- Not checked yetcites [59] source
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“However, clades terminating at a mass extinction event might be similarly truncated and are likely to have higher CGs for similar reasons.”
§ Clades reach highest morphological disparity early in their evolution > macroevolution | morphological disparity | morphospace | clade shape |
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: fails — The paper may give no reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it. The paper may give no reason why it holds. It may state two separate claims as one.
In the paper
“However, mass extinctions need not increase the subsequent availability of ecospace but may actually cause its collapse (60).”
§ Clades reach highest morphological disparity early in their evolution > Why Do Clades Have Early High Disparity?
What the sources say
- Not checked yetcites [60] source
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
None of the sources cited for this claim have been checked yet.
In the paper
“Many studies have recently followed similar protocols (27,(36)(37)(38), and we adopted these methods here as a unifying approach.”
§ Clades reach highest morphological disparity early in their evolution > macroevolution | morphological disparity | morphospace | clade shape |
What the sources say
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.
In the paper
“Morphological change under these circumstances may be rapid either because transitions are unusually large or because rates of cladogenesis are unusually high (even with”
§ Clades reach highest morphological disparity early in their evolution > Why Do Clades Have Early High Disparity?
What the sources say
- Not checked yetcites [29]
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“Our use of 0.5 as a null is slightly simplistic, therefore, but biased against our principal finding (namely that clades not terminating at a mass extinction event are bottom-heavy on average).”
§ Clades reach highest morphological disparity early in their evolution > Results and Discussion
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. It may state two separate claims as one.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“Within datasets, strict rules were applied to ensure that sampling was adequately uniform across known operational taxonomic units (OTUs) and through time, amalgamating taxa where necessary (Dataset S1).”
§ Clades reach highest morphological disparity early in their evolution > Materials and Methods
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“Fourth, the manner in which trajectories of disparity through time are quantified and classified is also variable.”
§ Clades reach highest morphological disparity early in their evolution > macroevolution | morphological disparity | morphospace | clade shape |
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim.
None of the sources cited for this claim have been checked yet.
In the paper
“The”
What the sources say
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim.
The paper relies on this without support.
The early high disparity model had not been tested systematically before this study.
“However, the validity of this early high disparity model has never been tested systematically.”
The paper relies on this without support.
The 98 sampled clades are representative of metazoan clades across the Phanerozoic.
“We compiled published discrete morphological and stratigraphic data for 98 vertebrate and invertebrate clades radiating throughout the Phanerozoic (Dataset S2).”
The paper relies on this without support.
Key innovations can arise at any time.
“key innovations (which can evolve at any time)”
The paper relies on this without support.
The 63 clades not terminating at a mass extinction were free-evolving and not otherwise truncated.
“we again focused on the 63”
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
The source backs part of the claim, not all of it — or backs it for a different population, condition or comparison.
In the citing paper
“Early bursts of morphological and taxonomic diversity should be associated with adaptive radiations [5] and many have been identified in the fossil record, ranging from the Cambrian radiation [27] to many invertebrate [28,29] and vertebrate [30,31] clades.”
From Novelty and Innovation in the History of Life (2015) · cites this paper as [29]
Experimental — accuracy not yet measured
Citations
Cites
(1945) · Annals of the Entomological Society of America · doi:10.1093/aesa/38.3.396 · Cited by 1,859
Simpson, G. G. (2005) · Kluwer Academic Publishers eBooks · doi:10.1007/0-306-47468-9_7 · Cited by 1,657
Smith, J. M., Burian, R. M., Kauffman, S. A., Alberch, P., Campbell, J., Goodwin, B. C., Lande, R., Raup, D. M., & Wolpert, L. (1985) · The Quarterly Review of Biology · doi:10.1086/414425 · Cited by 1,442
Early animal evolution: emerging views from comparative biology and geology
Knoll, A. H., & Carroll, S. B. (1999) · Science · doi:10.1126/science.284.5423.2129 · Cited by 821
Adaptive radiation: Contrasting theory with data
Gavrilets, S., & Losos, J. B. (2009) · Science · doi:10.1126/science.1157966 · Cited by 750
Benton, M. J. (2009) · Science · doi:10.1126/science.1157719 · Cited by 663
The Evolution of Morphological Diversity
Foote, M. (1997) · Annual Review of Ecology and Systematics · doi:10.1146/annurev.ecolsys.28.1.129 · Cited by 655
(1997) · Choice Reviews Online · doi:10.5860/choice.34-4488 · Cited by 530
The origin of species by natural selection.
Morgan, T. H. (2011) · Princeton University Press eBooks · doi:10.1037/13436-011 · Cited by 422
Evolution since Darwin: the first 150 years
(2011) · Choice Reviews Online · doi:10.5860/choice.48-5062 · Cited by 376
Research works printed but not linked: 2
- SJ Gould Wonderful Life (W. W. Norton, New York, 1989).
- ENK Clarkson Invertebrate Palaeontology & Evolution (Wiley, New York, 1998).
Cited by
Sorted by citations
Ecological Opportunity and Adaptive Radiation
Stroud, J. T., & Losos, J. B. (2016) · Annual Review of Ecology Evolution and Systematics · doi:10.1146/annurev-ecolsys-121415-032254 · Cited by 572
Mega-evolutionary dynamics of the adaptive radiation of birds
Cooney, C. R., Bright, J. A., Capp, E. J. R., Chira, A. M., Hughes, E. C., Moody, C. J. A., Nouri, L. O., Varley, Z. K., & Thomas, G. H. (2017) · Nature · doi:10.1038/nature21074 · Cited by 356
Developmental Bias and Evolution: A Regulatory Network Perspective
Uller, T., Moczek, A. P., Watson, R. A. R., Brakefield, P. M., & Laland, K. N. (2018) · Genetics · doi:10.1534/genetics.118.300995 · Cited by 286
Armbruster, W. S. (2016) · Functional Ecology · doi:10.1111/1365-2435.12783 · Cited by 239
Lloyd, G. T. (2016) · Biological Journal of the Linnean Society · doi:10.1111/bij.12746 · Cited by 227
Metadata
- Authors
- Hughes, M., Gerber, S., & Wills, M. A.
- Affiliations
- University of Bath (GB)
- Venue
- Proceedings of the National Academy of Sciences
- Publisher
- National Academy of Sciences
- Published
- 2013-07-24
- Volume
- 110
- Issue
- 34
- Pages
- 13875-13879
- ISSN
- 0027-8424 (ISSN-L)
- 1091-6490
- PMC
- PMC3752257
- OpenAlex
- W2040344633
- Cited by
- 262
- References
- 78
- Citations by year
- 2026: 14 · 2025: 18 · 2024: 10 · 2023: 19 · 2022: 13 · 2021: 23 · 2020: 24 · 2019: 38 · 2018: 26 · 2017: 24 · 2016: 23 · 2015: 17 · 2014: 11 · 2013: 2
- FWCI
- 11.97
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Locations
- Proceedings of the National Academy of Sciences (publishedVersion)
- Europe PMC (PubMed Central) (publishedVersion)
- PubMed Central (publishedVersion)
- PubMed (publishedVersion)
- Funders
- Leverhulme Trust (F/00 351/Z)
- Topics
- Physical Sciences › Earth and Planetary Sciences › Paleontology › Evolution and Paleontology Studies
- Life Sciences › Agricultural and Biological Sciences › Ecology, Evolution, Behavior and Systematics › Morphological variations and asymmetry
- Physical Sciences › Earth and Planetary Sciences › Paleontology › Paleontology and Evolutionary Biology
- Keywords
- morphological disparity, macroevolutionary trends, center of gravity, mass extinction, Phanerozoic, apomorphies, developmental constraints
- MeSH terms
- Anatomy, Comparative, Biological Evolution, Models, Biological, Phylogeny, Species Specificity
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
A language model drew the claims from the paper on 2026-10-07, under version 3 of the claim definition (model deepseek-v4.1-flash, prompt extract-v3).
A second model labelled each claim on 2026-10-07 (model jev-1.13-20260917, definition revision gold-guideline-v0.2).
Cited sources are checked with a language model’s help (gpt-6-sol).
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
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