The Big Five mass extinctions share a common macroevolutionary structure that existing frameworks—whether catastrophist or gradualist—fail to unify. This paper proposes that the primary determinant of extinction vulnerability is not the nature of the environmental perturbation (cooling, warming, anoxia, acidification) but the degree of evolutionary lock-in—the depth of path dependence, selective confirmation bias, and energetic streamlining—accumulated by a lineage prior to crisis onset. Drawing on the Fixation and Selection framework (Qin 2025), I argue that the reproductive law (the directional solidification of generational trajectories through genomic path dependence) progressively forecloses replicative degrees of freedom via a self-reinforcing positive feedback loop. Mass extinctions function as violent interruptions of this loop, selectively clearing the most deeply locked-in lineages and reopening replicative space for lineages retaining greater adaptive flexibility—those with richer evolutionary remainders.
This framework makes three claims: (1) pre-extinction environmental deterioration, documented across all five events, is structurally secondary to the pre-existing depth of lock-in, which determines vulnerability regardless of perturbation direction; (2) extinction selectivity patterns across the Big Five—favoring physiologically flexible, broadly adapted, generalist lineages—are unified not by a shared kill mechanism but by a shared structural principle: shallower lock-in confers survivorship; (3) the directionality observed in post-extinction radiations reflects not a teleological drive but the structural consequence that lineages with richer remainders are both more likely to survive and more likely to radiate into novel functional space. The specific nature of the terminal trigger is recast as an interaction partner that selects which axes of the pre-existing lock-in profile become lethal, not the root cause of the outcome.
1. Introduction
The study of mass extinctions has long been organized around a central question: what killed them? The identification of the Chicxulub impact crater (Penfield 1978; Alvarez et al. 1980), the dating of flood basalt provinces (Burgess et al. 2014; Blackburn et al. 2013), and the reconstruction of ocean redox states (Bartlett et al. 2018) have yielded increasingly precise terminal triggers for each of the Big Five events. Yet a complementary question has received less systematic attention: why were they vulnerable?
The distinction matters because the same environmental perturbation does not affect all lineages equally. End-Permian warming and anoxia preferentially eliminated marine clades with lower oxygen-carrying capacity (Song et al. 2024), while the end-Cretaceous impact winter selectively destroyed arboreal bird lineages through global forest collapse (Field et al. 2018). The kill mechanism differs—warming in one case, cooling in the other—yet both events preferentially eliminated deeply specialized lineages and spared broadly adapted generalists. This cross-event consistency in selectivity pattern, despite inconsistency in kill mechanism, demands a structural explanation.
This paper proposes such an explanation by applying the Fixation and Selection framework (Qin 2025a, 2025b) to the macroevolutionary record. The framework identifies a universal structural dynamic within evolutionary systems: the fourth step of each developmental round (fixation) forecloses the first step (selection), compressing degrees of freedom through an irreversible positive feedback loop of path dependence, confirmation bias, and energetic streamlining. In the biological round (5DD–8DD in the SAE dimensional sequence), this manifests as the progressive foreclosure of replicative freedom by reproductive law—the directional solidification of genomic trajectories across generations.
The core insight is that lock-in depth, not kill mechanism, is the primary structural determinant of extinction vulnerability. A lineage deep in the positive feedback loop—highly specialized, narrowly adapted, genetically streamlined—is fragile to any direction of environmental change, because it has exhausted its degrees of freedom for response. The specific perturbation selects the timing and the immediate physiological filter, but the underlying vulnerability is structural and precedes the crisis.
This reframing has three consequences. First, the longstanding debate between catastrophist and gradualist interpretations is repositioned: pre-extinction environmental deterioration and terminal triggers are not competing explanations but complementary aspects of the same structural process. Second, the apparent directionality of post-extinction radiations is explained without invoking teleology: lineages with richer remainders are both more likely to survive and more likely to explore novel functional space. Third, the specific nature of the trigger becomes structurally secondary.
2. Theoretical Framework: Fixation Forecloses Selection
2.1 The Universal Law
The Fixation and Selection framework (Qin 2025a) identifies a four-step cycle operating at every scale of the chisel-construct sequence: selection (birth) → determination (self) → extension (other) → fixation (death). Fixation, the irreversible solidification of direction, does not merely complete the cycle; it retroactively constrains the space of selection within the same round. The construct, once solidified, excludes the directions it did not take. This exclusion is the structural meaning of foreclosure.
Foreclosure is simultaneously indispensable and destructive. Without foreclosure there is no structure, without structure no remainder, without remainder no emergence of the next round. Yet within each round, foreclosure is a real, irreversible compression of degrees of freedom that cannot be rationalized away. Both sides hold simultaneously and cannot be reconciled (Qin 2025a, Ch. 1).
2.2 Round 2: Reproductive Law Forecloses Replication
In the biological round (5DD–8DD), the chisel is replication (5DD)—the first instance where patterns persist rather than dissipate—and the construct is reproductive law (8DD)—the directional solidification of generational trajectories through genomic inheritance. The foreclosure mechanism operates through three mutually reinforcing channels (Qin 2025b, Ch. 3):
Genetic path dependence. The genome is the biological form of memory. Each generation's adaptive "experience" is written into DNA, and evolution cannot retrace its steps. Dollo's law—complex features lost in evolution do not reappear—is a structural consequence: the genome has traveled too far in one direction, and all intermediate states required for reversal are disadvantageous under selection.
Confirmation bias in natural selection. Natural selection preferentially preserves "what already works," reinforcing the existing adaptive direction while eliminating alternatives. The narrower the ecological niche, the stronger the confirmation bias: the koala's exclusive eucalyptus diet, the giant panda's near-exclusive bamboo dependence, the cheetah's extreme locomotor specialization—each represents a genome "confirming" an ever-narrower path.
Biological energy conservation. Maintaining unused genetic pathways consumes resources. Selection favors streamlining: unused genes accumulate mutations and become pseudogenes. Cave fish lose eyes not because darkness causes degradation, but because the genes maintaining eyes are no longer preserved by selection pressure.
These three channels form a positive feedback loop: path dependence locks in direction → selection confirms direction → energy conservation eliminates alternatives → path dependence deepens. The loop is self-reinforcing and, in stable environments, produces exquisitely adapted organisms. In changing environments, it produces extinction.
A clarification against a potential tautology objection: the SAE contribution is not the observation that specialization produces fragility, but the claim that lock-in is a structural inevitability of reproductive law itself—not an accident or contingent outcome of particular evolutionary histories, but the necessary consequence of how the chisel-construct cycle operates in Round 2. The framework transforms an empirical regularity ("specialists die first") into a structural necessity ("the fixation step of every round forecloses the selection step of that same round").
Lock-in is not a single scalar but a multi-axis profile. Different perturbation types activate different axes: warming and hypoxia activate the respiratory-buffering axis (end-Permian); impact winter activates the habitat-dependence and trophic axes (K-Pg); glacioeustatic regression activates the geographic-range and thermal-niche axes (end-Ordovician). The framework's prediction is that the interaction between a lineage's lock-in profile and the perturbation profile determines vulnerability.
2.3 Mass Extinction as Violent Interruption
The Fixation and Selection framework draws a sharp distinction between the bridge (the structural emergence of a new round from the remainder of the current round's foreclosure) and mass extinction. Mass extinction is not a bridge. It is a catastrophe—an external force that violently clears existing pathways, forcibly reopening replicative space (Qin 2025b, §3.4). Yet it has a structural function analogous to the bridge's consequence: by clearing the most deeply locked-in lineages, it reopens the replicative space that foreclosure had compressed. The lineages that survive are, by structural necessity, those with shallower lock-in—broader adaptations, richer genetic diversity, more uncommitted degrees of freedom.
2.4 The Remainder as Survival Criterion
The SAE framework defines the remainder (余项) as that which survives every act of chiseling—the irreducible excess that no amount of structural solidification can eliminate (Qin 2025c). In the biological round, the remainder of reproductive law is offspring variability: each generation produces variation, but the organism does not choose which variations appear.
This concept maps directly onto the empirical survival criterion observed across mass extinctions: what survives is not "the most complex" or "the most adapted," but the lineage with the richest remainder—the greatest uncommitted degrees of freedom. Small body size, broad dietary range, wide geographic distribution, high reproductive rate, flexible metabolic capacity—these are all empirical manifestations of rich remainder: adaptive potential that has not yet been committed to a specific direction.
3. The Five Extinctions: Lock-in Depth as the Unifying Variable
3.1 End-Ordovician
Pre-extinction deterioration. The end-Ordovician extinction is increasingly understood as a prolonged, punctuated climate-sea level-habitat crisis rather than a short Hirnantian catastrophe (Rasmussen et al. 2019). Global redox proxy data document a global-scale anoxic event (HOAE) coincident with extinction onset and persisting through glaciation and deglaciation (Bartlett et al. 2018). Quantitative analysis supports a "common cause" signal: glacioeustatic sea-level fall and tropical cooling are implicated in the primary extinction pulse (Finnegan et al. 2012).
Lock-in and selectivity. Extinction risk correlates with maximum paleolatitude (a thermal tolerance proxy) and with the fraction of geographic range impacted by stratigraphic truncation (Finnegan et al. 2012). Exclusively tropical taxa—those most deeply locked into warm-water niches—are disproportionately eliminated. Models trained on earlier intervals underpredict extinction of tropical specialists, consistent with the framework's prediction: lock-in to a narrow thermal niche produces fragility when that niche contracts.
Post-extinction radiation. The aftermath catalyzed early radiations of jawed vertebrates (gnathostomes), facilitated by ecological release and atmospheric oxygen increases. The relevant novelty is functional: jaws and higher-activity predation niches represent new degrees of freedom in ecological space.
3.2 Late Devonian
Pre-extinction deterioration. The Late Devonian crisis is intrinsically multi-pulse. Astronomical tuning constrains the Kellwasser anoxic horizons to ~90–110 kyr durations, with environmental disruption beginning hundreds of kyr before the Frasnian-Famennian boundary (De Vleeschouwer et al. 2017). Terrestrial records reveal ecosystem collapse linked to ozone-layer reduction and elevated UV-B during rapid warming (Marshall et al. 2020).
Lock-in and selectivity. The clearest selectivity signal is vertebrate body size and life-history filtering: post-extinction ecosystems are dominated by small, fast-breeding ray-finned fishes, sharks, and tetrapods, while large, slow-breeding survivors fail to diversify (Sallan & Galimberti 2015). Large body size and slow reproduction are indicators of deep lock-in: long generation times, high energetic investment per offspring, narrow adaptive flexibility.
Post-extinction radiation. The Devonian-Carboniferous transition sees the diversification of crown-group tetrapods and later amniote origins, representing a fundamental expansion of terrestrial vertebrate functional space.
3.3 End-Permian
Pre-extinction deterioration. High-precision U-Pb chronology constrains the main extinction interval to ~60 ± 48 kyr, embedded in a longer-lived carbon-cycle disturbance persisting ~500 kyr (Burgess et al. 2014). Ultra-high-resolution proxy work documents a cascading sequence in the ~2,000 years preceding collapse: wildfires → enhanced terrestrial input → marine euxinia, with terrestrial ecosystem collapse preceding marine collapse (Dal Corso et al. 2022).
Lock-in and selectivity. The end-Permian provides the strongest case for explicitly physiological selectivity. Song et al. (2024) demonstrate that marine clades with lower oxygen-carrying capacity (hemerythrin proteins, O₂ diffusion-dependent respiration) experienced significantly greater extinction intensity and body-size reduction than clades with hemoglobin or hemocyanin. This respiratory-protein selectivity persists after controlling for geographic range and skeletal mineralogy. Knoll et al. (2007) independently identify preferential elimination of heavily calcified groups with limited respiratory and circulatory systems.
In the framework's terms, respiratory complexity is a measure of remainder richness at the physiological level. Hemoglobin/hemocyanin systems provide degrees of freedom for oxygen management under stress—adaptive capacity not yet committed to a single environmental regime. Hemerythrin systems and diffusion-dependent respiration represent deeper lock-in: functional, but only under stable oxygen conditions.
Post-extinction radiation. The transition produces the "Modern/Mesozoic" evolutionary fauna: more diverse predators, more complex predator-prey interactions, and a two-step ecosystem modernization across the Triassic. The respiratory-protein selectivity directly channels subsequent dominance structure: lineages with advanced oxygen-transport systems disproportionately populate the rebuilt ecosystems.
3.4 End-Triassic
Pre-extinction deterioration. High-precision U-Pb constraints link the extinction tightly to the onset of Central Atlantic Magmatic Province (CAMP) activity, with volcanism and associated atmospheric flux occurring in four pulses over ~600 kyr (Blackburn et al. 2013). Carbon-cycle perturbations and ocean acidification are documented as pre-boundary and boundary-crossing stressors.
Lock-in and selectivity. Functional/ecological selectivity analysis shows strong filtering against sessile suspension feeders, with pronounced tropical and reef-system impacts (Dunhill et al. 2018). Sessile, filter-feeding lifestyles in tropical reef settings represent triple lock-in: positional (attached to substrate), trophic (dependent on suspended particles), and thermal (restricted to warm, shallow water). Mobile, deposit-feeding, and broadly distributed forms survive preferentially.
Post-extinction radiation. The aftermath sets the stage for dinosaur dominance across ~136 Myr and, in the marine realm, accelerates the Mesozoic Marine Revolution—a long-term escalation of predator-prey interactions toward more active, mobile, and heavily defended forms (Vermeij 1977).
3.5 End-Cretaceous
Pre-extinction deterioration. Multiproxy temperature syntheses support significant global surface-ocean cooling through the Campanian-Maastrichtian interval (Linnert et al. 2014). Whether this climatic trend produced a measurable pre-impact decline in dinosaur diversity remains actively contested. Condamine et al. (2021) report declining diversification across six major dinosaur families beginning ~76 Ma. Dean et al. (2025) challenge this conclusion using Bayesian occupancy modeling, arguing that decreasing fossil detection probability can mimic biological decline.
The framework's position on this debate is that the specific question—whether dinosaurs were declining before impact—is structurally secondary. What matters is that non-avian dinosaurs, as large-bodied, long-generation, highly specialized megafauna, were deeply locked in by the Late Cretaceous. Whether environmental deterioration had already begun to expose this lock-in or whether the lock-in remained latent until the impact exposed it, the structural vulnerability was the same.
Lock-in and selectivity. Selectivity at the K-Pg is highly clade-dependent. Marine bivalves show few classic trait selectivities beyond geographic range (Jablonski & Raup 1995). For birds, survivorship is biased toward non-arboreal ecology, consistent with global forest collapse as an ecological filter (Field et al. 2018). Non-avian dinosaurs represent extreme lock-in: large body size, long generation times, likely dependence on warm temperatures, and dietary specialization.
Post-extinction radiation. The aftermath produces the radiation of crown birds and placental mammals. Mammalian radiation follows the pattern predicted by the framework: small-bodied, generalist, high-reproductive-rate lineages—those with the richest remainder—fill the vacated ecological space and subsequently diversify into the full range of Cenozoic ecological niches.
4. Directionality Without Teleology
4.1 The Passive-vs-Driven Trend Debate
A central methodological challenge is the distinction between passive and driven trends (McShea 1994). A passive trend—the expansion of variance away from a lower bound without directional selection—can produce an apparent increase in maximum complexity without any organism being selected for greater complexity as such. A driven trend requires directional selection.
The framework's contribution is to recast the question. The directionality observed across extinction-radiation cycles is neither passive diffusion nor driven selection toward complexity. It is a structural consequence of the remainder principle: each extinction event selectively removes the most deeply locked-in lineages (those with the least remainder) and preserves those with the most remainder. Over multiple extinction-radiation cycles, this filtering produces a ratchet-like pattern: each post-extinction radiation begins from a surviving pool enriched in remainder, and each new adaptive radiation explores a wider functional space than the pre-extinction radiation it replaces.
4.2 Empirical Anchors for the Remainder-Enrichment Ratchet
Sepkoski's evolutionary faunas. Factor-analytic identification of stepwise Phanerozoic transitions reveals abrupt reorganizations of dominance structure broadly associated with major crises (Sepkoski 1981). Each successive evolutionary fauna dominates a broader range of ecological space than its predecessor—consistent with remainder enrichment through iterative filtering.
The Mesozoic Marine Revolution. Vermeij (1977) documents long-term escalation of predator-prey interactions and the rise of mechanically more durable, more mobile, more actively defended forms in post-Permian and post-Triassic marine ecosystems. The survivors of end-Permian and end-Triassic filtering were disproportionately mobile, metabolically active, and physiologically flexible—remainder-rich—and their subsequent radiation intensified ecological interactions.
Respiratory-protein selectivity at the end-Permian. Song et al. (2024) provide the most direct empirical link between physiological remainder and post-extinction dominance structure: preferential survival of clades with advanced oxygen-transport systems directly channels the composition of the subsequent Mesozoic fauna.
Incumbent replacement. Rosenzweig & McCord (1991) define evolutionary progress as the spread of key adaptations that relax trade-offs. In the framework's terms, each "key adaptation" is a new degree of freedom—a new dimension of remainder—that expands the functional space available to the lineage.
4.3 Arguments Against a Universal Ratchet—and the Framework's Response
Passive trend mechanisms (McShea 1994): the framework does not claim directional selection toward complexity but structural filtering by remainder richness, producing a driven trend by selective removal of low-remainder lineages.
Inconsistent selectivity across events and taxa (Payne & Finnegan 2023): the framework predicts selectivity on remainder richness, not on any single trait. Remainder richness manifests differently: as respiratory physiology in marine invertebrates, as ecological flexibility in birds, as body size and reproductive rate in vertebrates.
Post-extinction ecological simplification (Hull 2015): remainder-rich survivors are not pre-adapted to the post-extinction environment; they have potential, not pre-built solutions. Initial simplification reflects the gap between surviving with degrees of freedom and deploying them.
Heterogeneous environmental drivers: the heterogeneity of kill mechanisms is not a problem to be explained away but the feature that confirms the structural nature of vulnerability. Lock-in depth predicts fragility regardless of perturbation direction.
5. The Trigger as Interaction Partner
A key implication of the framework is that the specific nature of the terminal trigger—asteroid impact, flood basalt volcanism, glaciation, marine transgression—is neither the root cause of extinction (as strong catastrophism holds) nor merely a timing device. The trigger is an interaction partner: it determines which axes of the pre-existing lock-in profile are activated, and therefore which lineages cross the threshold from latent vulnerability to actual extinction.
At the K-Pg, the Chicxulub impact produced global forest collapse, which activated the habitat-dependence axis: arboreal bird lineages died because their ecological substrate was physically destroyed (Field et al. 2018). Had the same biota faced a slow warming event instead, the habitat-dependence axis might not have been activated, and a different subset of locked-in lineages—those locked on the thermal-buffering axis—would have been preferentially eliminated. At the end-Permian, rapid warming and ocean deoxygenation activated the respiratory-buffering axis (Song et al. 2024). The lock-in profile was pre-existing; the perturbation determined which part of it became lethal.
Gradualism correctly identifies that vulnerability builds over extended timescales through the positive feedback loop of lock-in. Pre-extinction environmental deterioration, documented across all five events (Payne & Finnegan 2023), is the observable trace of this vulnerability accumulation.
Catastrophism correctly identifies that the interruption of the loop requires an external force of sufficient magnitude to overcome the inertia of locked-in systems.
The synthesis: catastrophe and gradualism are not competing causes but sequential phases of the same process—the feedback loop deepens vulnerability (gradual phase), and an external perturbation exceeds the loop's absorption capacity on specific axes (catastrophic phase). The trigger does not merely select the timing; it selects the filter.
6. Predictions
Lock-in depth should predict extinction risk better than any single trait. Composite indices of lock-in (combining niche breadth, geographic range, dietary specialization, generation time, and genetic diversity) should outperform single-trait models in predicting genus-level extinction across events.
The most specialized species should show suppressed genetic variation. Extremely specialized lineages approaching extinction should exhibit lower genetic diversity than sympatric generalists, even controlling for population size. Modern comparative genomics of endangered specialists (cheetah, giant panda, koala) versus sympatric generalists provides a contemporary test.
Post-extinction recovery rate should correlate inversely with pre-extinction community lock-in depth. Events that eliminate more deeply locked-in communities (the end-Permian, with 96% marine species loss) should show slower recovery than events that eliminate less deeply locked-in communities. The empirical pattern—end-Permian recovery ~5–10 Myr versus K-Pg recovery ~1–3 Myr—is consistent.
The greatest adaptive radiations should follow the most thorough clearings of lock-in. The magnitude of post-extinction radiation should correlate with the completeness with which the preceding extinction eliminated deeply locked-in lineages, not simply with the percentage of species lost.
Kill mechanism should not predict post-extinction radiation structure. Events with different kill mechanisms (warming vs. cooling vs. impact) but similar pre-extinction lock-in distributions should produce similar post-extinction radiation patterns. Conversely, events with similar kill mechanisms but different pre-extinction lock-in distributions should produce different radiation patterns.
7. Discussion: What the Framework Does Not Explain
The framework deliberately leaves two questions open.
The first concerns scope. If lock-in depth is a continuous variable and perturbation severity is a continuous variable, their interaction should produce a continuous distribution of extinction outcomes, not a discrete binary of "bridge" and "catastrophe." The framework predicts the same structural logic applies across the spectrum. The Big Five are distinguished not by a qualitatively different mechanism but by quantitative extremity—perturbations severe enough to exceed the absorption capacity of even moderately locked-in lineages, producing biosphere-scale clearance and radiation. Whether this can be formalized into a predictive model of extinction severity as a function of lock-in distribution × perturbation magnitude is a challenge for future work.
The second concerns directionality. The remainder-enrichment ratchet explains why each post-extinction radiation tends to produce organisms with richer adaptive potential than the pre-extinction dominants. It does not explain why the sequence of extinction-radiation cycles, viewed across the full Phanerozoic, produces an apparent trajectory from simple marine invertebrates to complex terrestrial vertebrates to self-aware primates. This trajectory may be fully explicable as the cumulative effect of five rounds of remainder-enrichment filtering operating on a biosphere that began near the lower bound of complexity. Whether the pattern requires a deeper explanation is left to the reader.
8. Conclusion
The Big Five mass extinctions are unified not by a shared kill mechanism but by a shared structural dynamic: the progressive foreclosure of replicative freedom through path dependence, confirmation bias, and energetic streamlining, followed by violent interruption and selective clearance. The depth of evolutionary lock-in—not the direction of environmental change—determines which lineages are vulnerable. The richness of evolutionary remainder—not physiological complexity per se—determines which lineages survive and radiate.
This framework resolves the apparent paradox that mass extinctions are simultaneously destructive and generative: destruction falls preferentially on the most locked-in (least remainder), while generation arises preferentially from the least locked-in (most remainder). The iterative application of this filter across five major events produces a ratchet-like enrichment of adaptive potential in the surviving biota, which manifests empirically as the stepwise increase in organizational complexity across the Phanerozoic.
The specific trigger—asteroid, flood basalt, glaciation—selects the timing. The structure selects the outcome.
DOI: 10.5281/zenodo.19225113References
Alvarez, L.W., Alvarez, W., Asaro, F., & Michel, H.V. (1980). Extraterrestrial cause for the Cretaceous-Tertiary extinction. Science, 208, 1095–1108.
Bartlett, R., et al. (2018). Abrupt global-ocean anoxia during the Late Ordovician–early Silurian detected using uranium isotopes of marine carbonates. PNAS, 115, 5896–5901.
Blackburn, T.J., et al. (2013). Zircon U-Pb geochronology links the end-Triassic extinction with the Central Atlantic Magmatic Province. Science, 340, 941–945.
Burgess, S.D., Bowring, S., & Shen, S. (2014). High-precision timeline for Earth's most severe extinction. PNAS, 111, 3316–3321.
Condamine, F.L., Guinot, G., Benton, M.J., & Currie, P.J. (2021). Dinosaur biodiversity declined well before the asteroid impact, influenced by ecological and environmental pressures. Nature Communications, 12, 3833.
Dal Corso, J., et al. (2022). Environmental crises at the Permian-Triassic mass extinction. Nature Reviews Earth & Environment, 3, 197–214.
Dean, C.D., et al. (2025). The structure of the end-Cretaceous dinosaur fossil record in North America. Current Biology, 35.
De Vleeschouwer, D., et al. (2017). Timing and pacing of the Late Devonian mass extinction event regulated by eccentricity and obliquity. Nature Communications, 8, 2268.
Dunhill, A.M., Foster, W.J., Sciberras, J., & Twitchett, R.J. (2018). Impact of the Late Triassic mass extinction on functional diversity and composition of marine ecosystems. Palaeontology, 61, 133–148.
Field, D.J., et al. (2018). Early evolution of modern birds structured by global forest collapse at the end-Cretaceous mass extinction. Current Biology, 28, 1825–1831.
Finnegan, S., et al. (2012). Climate change and the selective signature of the Late Ordovician mass extinction. PNAS, 109, 6829–6834.
Hull, P.M. (2015). Life in the aftermath of mass extinctions. Current Biology, 25, R941–R952.
Jablonski, D. (1986). Background and mass extinctions: the alternation of macroevolutionary regimes. Science, 231, 129–133.
Jablonski, D. & Raup, D.M. (1995). Selectivity of end-Cretaceous marine bivalve extinctions. Science, 268, 389–391.
Jablonski, D. & Edie, S.M. (2025). Mass extinctions and their rebounds: a macroevolutionary framework. Paleobiology.
Knoll, A.H., Bambach, R.K., Payne, J.L., Pruss, S., & Fischer, W.W. (2007). Paleophysiology and end-Permian mass extinction. Earth and Planetary Science Letters, 256, 295–313.
Linnert, C., et al. (2014). Evidence for global cooling in the Late Cretaceous. Nature Communications, 5, 4194.
Marshall, J.E.A., et al. (2020). UV-B radiation was the Devonian-Carboniferous boundary terrestrial extinction kill mechanism. Science Advances, 6, eaba0768.
McShea, D.W. (1994). Mechanisms of large-scale evolutionary trends. Evolution, 48, 1747–1763.
Payne, J.L. & Finnegan, S. (2023). Selectivity of mass extinctions: Patterns, processes, and future directions. Cambridge Prisms: Extinction, 1, e10.
Qin, H. (2025a). Fixation and Selection (I)—Causal Law Forecloses Distinction. Self-as-an-End Theory Series. DOI: 10.5281/zenodo.18859363.
Qin, H. (2025b). Fixation and Selection (II)—Reproductive Law Forecloses Replication. Self-as-an-End Theory Series. DOI: 10.5281/zenodo.18859393.
Qin, H. (2025c). SAE Methodological Overview: The Chisel-Construct Cycle. DOI: 10.5281/zenodo.18842450.
Qin, H. (2025d). From Replication to Cognition: The Chisel-Construct Cycle of Life (5D–8D). DOI: 10.5281/zenodo.18807376.
Qin, H. (2025e). Periodic Table of Life (Part I)—From Causality to Reproduction. DOI: 10.5281/zenodo.18818107.
Qin, H. (2025f). Periodic Table of Life (Part II)—From Reproduction to Prediction. DOI: 10.5281/zenodo.18818149.
Rasmussen, C.M.Ø., et al. (2019). Cascading trend of Early Paleozoic marine radiations paused by Late Ordovician extinctions. PNAS, 116, 7207–7213.
Rosenzweig, M.L. & McCord, R.D. (1991). Incumbent replacement: evidence for long-term evolutionary progress. Paleobiology, 17, 202–213.
Sallan, L. & Galimberti, A.K. (2015). Body-size reduction in vertebrates following the end-Devonian mass extinction. Science, 350, 812–815.
Sepkoski, J.J. (1981). A factor analytic description of the Phanerozoic marine fossil record. Paleobiology, 7, 36–53.
Song, H., et al. (2024). Respiratory protein-driven selectivity during the Permian-Triassic mass extinction. The Innovation, 5, 100618.
Vermeij, G.J. (1977). The Mesozoic Marine Revolution: evidence from snails, predators, and grazers. Paleobiology, 3, 245–258.