Tags:
Paleontology,
Paleobiology,
Community ecology,
Macroecology,
Macroevolution,
Phylogenetics,
Biogeography
Publications
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Yan, Feng,; Daoliang, Chu,; Yunfei, Huang,; Jiankang, Lai,; Liow, Lee Hsiang & Xiaokang, Liu,
[Show all 9 contributors for this article]
(2026).
ESSDD - PhaFoS: A Global Database of Phanerozoic Foraminiferal Size.
Earth System Science Data.
doi:
10.5194/essd-2026-458.
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Body size is a key phenotypic trait of living organisms, reflecting ecological function and individual metabolism. Evolutionary changes in body size also provide information on interactions between the organisms and their changing physical and biotic environments. Despite the utilitarian value of body size for understanding evolution and past environments, we lack a standardized, occurrence-based, Phanerozoic body size database for most groups of organisms, limiting large-scale studies of size evolution and size-environment interactions. Foraminifera are an ideal group to fill this data gap, given their abundant fossil record, extensive palaeogeographic distribution, and sensitivity to environmental changes. Here, we present PhaFoS, short for Phanerozoic Foraminifera Size database. PhaFoS compiles 118,885 specimens, of which 103,121 from 963 published papers and the remaining 15,764 from our field colletions, representing 4,167 genera and 34,256 species. Each record is linked to standardized and queryable metadata fields, including test volume (log₁₀ μm³), taxonomy, stratigraphic age, and both modern and paleogeographic coordinates. This database can be used to quantify temporal and spatial patterns of foraminiferal body-size over the Phanerozoic, and to explore the body size relationships with environmental conditions and their changes. The data files described in this paper are available at https://doi.org/10.5281/zenodo.20777319 (Feng et al., 2026).
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Liow, Lee Hsiang; Saulsbury, James G & Taylor, Paul D
(2026).
Enhanced dominance by cheilostomes relative to cyclostomes in low-latitude bryozoan assemblages through 100 million years.
Evolutionary Journal of the Linnean Society.
doi:
10.1093/evolinnean/kzag027.
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Abstract Clade-clade interactions are thought to be a major force in the changing representation of organisms with similar ecological niches over time and space. It has long been known that the global number of cheilostome bryozoan species have increasingly outnumbered cyclostome bryozoan species, due to higher rates of both origination and extinction in cheilostomes. However, the latitudinal differences in this evolutionary turnover, and their ecological mechanisms, have been underexplored. Here we test the hypothesis that the numerical dominance of cheilostome species is enhanced at low latitudes today, and quantify this dominance in the geological past. Our data comes from 288 extant and 1257 fossil bryozoan assemblages reported in the published literature. We show using generalized linear mixed models that assemblages contain a greater proportion of cheilostome species in lower latitudes through the last 100 million years. We discuss why higher latitudes may have represented a stronghold for cyclostomes, even as cheilostomes have continued to outnumber cyclostomes in species richness over the Cenozoic. We hypothesize that a combination of lower average temperatures and greater seasonality could give cyclostome bryozoans with relatively slower metabolism an edge in higher latitudes, even as cheilostome bryozoan species numbers dominate globally.
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Dowding, Elizabeth M.; Skawina, Aleksandra; Baets, Kenneth De; Clements, Thomas; Dentzien-Dias, Paula & Huntley, John W.
[Show all 14 contributors for this article]
(2026).
Interpreting Biotic Interactions in the Fossil Record: Evidence and Evolutionary Significance.
Annual Review of Ecology, Evolution and Systematics.
ISSN 1543-592X.
doi:
https:/www.annualreviews.org/content/journals/10.1146/annurev-ecolsys-102924-044136.
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Fossil biotic interactions (fBIs) provide a critical but underutilized window into the ecological and evolutionary dynamics of life through time. Unlike modern ecological data, the fossil record captures the long-term consequences of short-term and local interactions, offering insights into biodiversity, extinction, adaptation, and ecosystem function. We review the contributions of the fossil record to studies of biotic interactions, propose a unified framework for reporting fBI data, and outline the interpretative challenges unique to fossils, including taphonomy and the inability to directly observe behavior. This review traces the process of knowledge creation from specimen-level evidence to inferred interactions, highlights insights gained from different fBI types, and advocates for standardized nomenclature and reporting. The fossil record is indispensable for understanding how interactions evolve, collapse, or persist across environmental crises, providing the foundation for linking organismal observations to evolutionary insights on how life has shaped—and been shaped by—biotic interactions.
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Baalsrud, Helle T; Tørresen, Ole K; Danneels, Bram; Ferrari, Giada; Tooming-Klunderud, Ave & Skage, Morten
[Show all 12 contributors for this article]
(2026).
Chromosomal fusions shaped the genome of the greater hornwrack bryozoan (Flustra foliacea) (Linnaeus, 1758).
Journal of Heredity.
ISSN 0022-1503.
117(4),
p. 750–760.
doi:
https:/academic.oup.com/jhered/article/117/4/750/8497176.
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The phylum Bryozoa is an understudied, yet commonly occurring, globally distributed bilaterian metazoan organismal group. They have a colonial lifestyle and an evolutionary history that spans at least 480 million years but likely longer. Despite their contentious phylogenetic affinities among metazoans, disproportionately few genomic investigations have been performed thus far. Here, we describe the first chromosome-level genome assembly of an individual Flustra foliacea colony belonging to the order Cheilostomatida, collected in southern Norway. The haplotype-resolved assembly of F. foliacea contains two pseudo-haplotypes spanning 956 megabases and 880 megabases, respectively. Both assemblies are highly complete both in terms of scaffolding (>90% of sequences placed in eight autosomal chromosomal pseudomolecules), and gene content (BUSCO completeness scores >90%). We also present gene and repeat annotations of the two assemblies. A comparison of our newly sequenced F. foliacea with five previously published bryozoan genomes supports the hypothesis that the group has undergone extensive genome rearrangements. This includes multiple chromosomal fusions in F. foliacea since their split with other cheilostome bryozoans. These fusions were enriched with long terminal repeat retrotransposons, highlighting the complex interplay between genome organization and genomic repeats. Our study contributes to a deeper understanding of bryozoan genome evolution and the role of repeats in metazoan genome organization.
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Dowding, Elizabeth M.; Dunne, Emma M.; Collins, Katie S.; Cryer, Katheryn; Baets, Kenneth De & Dimitrijević, Danijela
[Show all 22 contributors for this article]
(2026).
The billion-dollar case for sustaining palaeontology’s digital databases.
Nature Ecology and Evolution.
doi:
10.1038/s41559-026-02985-8.
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The digital revolution has transformed palaeontology through the development of openly accessible, community-driven databases that underpin some of the most complex and large-scale empirical studies of the history of life on Earth. These systems safeguard high-effort, volunteered data and have revealed major macroevolutionary patterns, including the ‘Big 5’ mass extinctions. These efforts also represent remarkable global scientific and financial investment, which is continually required to support the next generation of databases and associated research. Here we conducted a survey of 118 palaeontological and allied Earth science databases, analysing their diversity dynamics, including origination and extinction rates. We show that approximately 85% of all community-curated databases have lifespans of less than 15 years, putting decades of investment at risk. We show that database creation effort has increased in the past 30 years, with peaks in database loss related to 5-year funding cycles. We advocate for strategies to enhance database longevity, including sustained funding models, stronger institutional support and modular backend architectures that better link international community databases to each other and to fossil specimens.
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Ma, Junye; Liow, Lee Hsiang & Taylor, Paul D.
(2025).
Zooid size reduction in cyclostome bryozoans from the Late Triassic to the present‐day.
Palaeontology.
ISSN 0031-0239.
68(5).
doi:
10.1111/pala.70027.
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Body size evolution is a focus of palaeobiological interest, but few studies have examined long‐term changes in the size of the modular zooids of colonial animals. Here we investigate changes in zooid size from the Late Triassic to the present‐day among encrusting cyclostome bryozoans of a common morphotype attributed informally to ‘ Berenicea ’. We begin with the naïve hypothesis that cyclostome bryozoans should demonstrate size evolution similar to cheilostome bryozoans, which have maintained a constant mean zooid size. Unexpectedly, a striking pattern of decreasing zooid size through time was found in ‘ Berenicea ’. We then hypothesized that decreasing levels of oxygen could make smaller zooid sizes more optimal because of their greater surface area/volume; cyclostome zooid size might be tracking a changing adaptive landscape over 200 million years. Despite some evidence for a statistical correlation between ‘ Berenicea ’ zooid size and oxygen, there is no hint of any causal relationship between them when formal timeseries analysis tools, based on linear stochastic differential equations, are applied. Furthermore, neither origination rates of cheilostomes, known to be superior spatial competitors, nor assemblage‐level increases in cheilostome representation, are associated with ‘ Berenicea ’ zooid size changes. However, there is some support for a switch in the tempo of cyclostome zooid size change at c. 165 to 160 Ma and then again at c. 78 Ma.
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Saulsbury, James; Piwoni-Piórewicz, Anna; Kuklinski, Piotr; Martino, Emanuela Di & Liow, Lee Hsiang
(2025).
Evolution of skeletal mineralogy in cheilostome bryozoans from calcite to aragonite seas.
Geology.
ISSN 0091-7613.
doi:
10.1130/g53795.1.
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Under the calcite-aragonite seas hypothesis, the evolutionary history of calcifying marine organisms reflects changes in global seawater chemistry, alternately favoring precipitation of skeletons made of calcite or aragonite. Most calcifying groups including corals, coccolithophores, and stromatoporoids do not switch mineralogies in response to these changes; instead, they expand and dwindle as their favored seawater conditions come and go. Cheilostome bryozoans have been suggested as an exception to this rule, apparently transitioning between aragonite and calcite many times. These changes have never been surveyed in detail, but have important consequences for material properties, fossil preservation, and the capacity of marine organisms to adapt to environmental change. We used new large-scale phylogenetic, paleontological, and mineralogical data sets to analyze the evolution of skeletal mineralogy in cheilostomes as they diversified across the early Cenozoic calcite-aragonite seas transition. Ancestral state reconstructions and stochastic character maps indicate at least 50 independent acquisitions of partly or fully aragonitic skeletons from calcitic ancestors, with many more transitions toward the aragonitic state than away from it. Fossil faunas are dominated almost entirely by calcitic species in the Cretaceous, but bimineralic species become common by the Oligocene, and aragonitic species by the Pliocene−Pleistocene. Phylogenetic and fossil analyses reveal a coherent timeline consistent with the shift to aragonite seas. Cheilostome skeletal development may be predisposed to mineralogical flexibility, with adaptive consequences for colony construction and modularity.
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Fastovich, David; Meyers, Stephen; Saupe, Erin E.; Williams, John W.; Dornelas, Maria & Dowding, Elizabeth M.
[Show all 24 contributors for this article]
(2025).
Coupled, decoupled, and abrupt responses of vegetation to climate across timescales.
Science.
ISSN 0036-8075.
389(6755),
p. 64–68.
doi:
10.1126/science.adr6700.
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Climate and ecosystem dynamics vary across timescales, but research into climate-driven vegetation dynamics usually focuses on singular timescales. We developed a spectral analysis–based approach that provides detailed estimates of the timescales at which vegetation tracks climate change, from 101 to 105 years. We report dynamic similarity of vegetation and climate even at centennial frequencies (149−1 to 18,012−1 year−1, that is, one cycle per 149 to 18,012 years). A breakpoint in vegetation turnover (797−1 year−1) matches a breakpoint between stochastic and autocorrelated climate processes, suggesting that ecological dynamics are governed by climate across these frequencies. Heightened vegetation turnover at millennial frequencies (4650−1 year−1) highlights the risk of abrupt responses to climate change, whereas vegetation-climate decoupling at frequencies >149−1 year−1 may indicate long-lasting consequences of anthropogenic climate change for ecosystem function and biodiversity.
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Liow, Lee Hsiang & Quental, Tiago B.
(2025).
Biotic interactions and their consequences for macroevolution: learning from the fossil record and beyond.
Paleobiology.
ISSN 0094-8373.
51(1),
p. 71–82.
doi:
10.1017/pab.2024.32.
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Every organism interacts with a host of other organisms of the same and different species throughout its life. These biotic interactions have varying influences on the reproduction and dispersal of the organism, and hence also the population and species lineage to which the organism belongs. By extension, biotic interactions must contribute to the macroevolutionary patterns that we observe in the fossil record, but exactly how, when, and why are research questions we have been asking before the start of the journal Paleobiology. In this contribution for Paleobiology’s 50th anniversary, we present a brief overview of how paleobiologists have studied biotic interactions and their macroevolutionary consequences, recognizing paleontology’s unique position to contribute data and insights to the topic of interspecies interactions. We then explore, in a semi-free-form manner, what promising avenues might be open to those of us who use the fossil record to understand biotic interactions. In general, we emphasize the need for increased effort surrounding the understanding of ecological details, integration of different types of information, and model-based approaches.
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Pham, Karen Van-Thu; Liow, Lee Hsiang & Ivory, Sarah J
(2025).
Diverging evolutionary trajectories for palm seed sizes in mainland Africa and Madagascar.
Evolution.
ISSN 0014-3820.
79(5),
p. 711–723.
doi:
10.1093/evolut/qpaf010.
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Seed size is a trait which determines survival rates for individual plants and can vary as a result of numerous trade-offs. In the palm family (Arecaceae) today, there is great variation in seed sizes. Past studies attempting to establish drivers for palm seed evolution have sometimes yielded contradictory findings in part because modern seed size variations are complicated by long-term legacies, including biogeographic differences across lineages. Here, we examined palm seed size evolution in 2 adjacent regions (mainland Africa and Madagascar) utilizing single- and multi-regime Brownian Motion and Ornstein-Uhlenbeck processes. We explicitly take into account species’ evolutionary histories to investigate whether there may be shared evolutionary pressures over regional scales. We found that regional selection pressures do exist for palm seed lengths, but these pressures are distinct in mainland Africa and Madagascar, despite the 2 regions’ proximity. Our study indicates that evolutionary drivers may differ in these 2 regions, highlighting the importance of reconsidering the widespread assumption to view mainland Africa and Madagascar as a single evolutionary region.
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Hunt, Gene; Voje, Kjetil L. & Liow, Lee Hsiang
(2025).
Punctuated equilibrium: State of the evidence.
Paleobiology.
ISSN 0094-8373.
51(4),
p. 652–661.
doi:
10.1017/pab.2024.31.
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Despite its many extensions and implications, we argue that punctuated equilibrium itself has two core, empirical claims: (1) stasis dominates within fossil species; and (2) morphological change is concentrated in pulses that occur associated with speciation. Here we assess the state of the evidence for these two claims, 50 years after punctuated equilibrium’s foundational paper. Spurred by controversy, paleontologists have amassed a large number of case studies in which morphology in species-level lineages is tracked over time. Modern, likelihood-based methods have been used to fit to these data models of stasis, random walks, and directional trends, as well as more complex dynamics. Compilations reveal that the directional trends predicted by gradualist expectations are infrequent. Although stasis is commonly observed, it is favored in less than half of cases, and meandering random walks or more complex models generally account for the majority of cases. The second claim of punctuated equilibrium has received much less empirical scrutiny than the first. Although speciational pulses are plausible in theory, only a few paleontological studies integrate ancestor–descendant time series into a phylogenetic framework as is needed to estimate cladogenetic change and compare it with anagenesis. These studies, as well as more indirect analyses of extant clades, suggest that speciational change can occur, but we cannot yet assess with confidence its frequency or importance compared with anagenetic changes.
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Wilson, Connor J.; Reitan, Trond & Liow, Lee Hsiang
(2024).
Unveiling the underlying drivers of Phanerozoic marine diversification.
Proceedings of the Royal Society of London. Biological Sciences.
ISSN 0962-8452.
291.
doi:
10.1098/rspb.2024.0165.
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In investigating global patterns of biodiversity through deep time, many large-scale drivers of diversification have been proposed, both biotic and abiotic. However, few robust conclusions about these hypothesized effectors or their roles have been drawn. Here, we use a linear stochastic differential equation (SDE) framework to test for the presence of underlying drivers of diversification patterns before examining specific hypothesized drivers. Using a global dataset of observations of skeletonized marine fossils, we infer origination, extinction and sampling rates (collectively called fossil time series) throughout the Phanerozoic using a capture–mark–recapture approach. Using linear SDEs, we then compare models including and excluding hidden (i.e. unmeasured) drivers of these fossil time series. We find evidence of large-scale underlying drivers of marine Phanerozoic diversification rates and present quantitative characterizations of these. We then test whether changing global temperature, sea-level, marine sediment area or continental fragmentation could act as drivers of the fossil time series. We show that it is unlikely any of these four abiotic factors are the hidden drivers we identified, though there is evidence for correlative links between sediment area and origination/extinction rates. Our characterization of the hidden drivers of Phanerozoic diversification and sampling will aid in the search for their ultimate identities.
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Liow, Lee Hsiang; Porto, Arthur & Martino, Emanuela Di
(2024).
Trait-Fitness Associations via Fecundity and Competition in a Two-Million-Year-Long Fossil Record.
The American Naturalist.
ISSN 0003-0147.
204(3),
p. 258–273.
doi:
10.1086/731332.
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The evolution of phenotypic traits is usually studied on generational times or across species on million-year timescales. We bridge this conceptual gap by using high density sampling of a species lineage, Microporella agonistes (Bryozoa, Cheilostomatida), over 2 million years of its evolutionary history, to ask if trait-fitness associations are consistent with evolutionary trait models often applied to phenotypic time series. We use average fecundity and competitive outcome as two different fitness components, where competitive outcome is a proxy for partial survival. Examining three quantitative traits in multivariate analyses, we present evidence that some traits experienced substantial selective pressures, in part controlled by past environments. A complex interplay of resource competition with an altering set of competitors and past temperatures, has contributed to the changing patterns of phenotypes within the focal species. A comparison with congeneric species living in the same regional community suggests that size traits are more temporally variable and less constrained than shape traits. Our analyses also show that while controls on phenotypes are complex and varied in time, ecological and evolutionary processes that unfold on shorter time scales are not inconsistent with macroevolutionary patterns observed on longer timescales.
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Piwoni-Piórewicz, Anna; Liow, Lee Hsiang; Krzemińska, Małgorzata; Chełchowski, Maciej; Iglikowska, Anna & Ronco, Fabrizia Nina
[Show all 28 contributors for this article]
(2024).
Skeletal mineralogy of marine calcifying organisms shaped by seawater temperature and evolutionary history—A case study of cheilostome bryozoans.
Global Ecology and Biogeography.
ISSN 1466-822X.
33(8).
doi:
10.1111/geb.13874.
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Aim Quantify the contribution of environmental factors (water temperature, salinity and depth) and evolutionary history to varied skeletal mineralogy in calcifying marine organisms. Location Global Ocean. Time period Present. Major taxa studied Order: Cheilostomatida; Phylum: Bryozoa. Methods We employed X-ray diffraction (XRD) to analyse the skeletal mineral composition of 872 individual colonies, representing 437 bryozoan species, in terms of calcite/aragonite ratios. We integrated these data with equivalent published data, thus reaching 981 species, and applied linear models (LMs), generalized linear models (GLMs) and phylogenetic generalized least squares models (PGLSs) to investigate the influences of temperature, salinity, depth and phylogenetic history on the mineralogy of nearly 1000 cheilostome bryozoan species. Results Cheilostome bryozoans vary considerably in their skeletal mineral composition: in our dataset 65% of the species possess purely calcite skeletons, 15% exclusively employ aragonite and 20% exhibit mixed (i.e. calcite and aragonite) mineralogies. Temperature is the predominant measured environmental factor influencing bryozoan skeletal mineralogy, accounting for 20% of its variability across species, when phylogenetic relatedness is unaccounted for. Bryozoans in lower latitudes, characterized by higher seawater temperatures, have higher aragonite concentrations. By accounting for phylogenetic structure using a subset of 87 species for which we have topological information, 40% of the observed mineralogical variability could be attributed to present-day temperature. In contrast, depth and salinity played minor roles, explaining less than 1% of the mineralogical variation each. Main conclusions This study emphasizes the influence of evolutionary history on the mineralogical variability of calcifying organisms, even when it can be shown that a single environmental factor (temperature) explains a substantial amount of this variability. When confronted with changing temperature, calcifiers such as bryozoans are likely to respond in diverse ways, depending on the species, given their phylogenetic relatedness and the external conditions they meet.
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Tsuboi, Masahito; Sztepanacz, Jacqueline; Lisle, Stephen De; Voje, Kjetil L.; Grabowski, Mark & Hopkins, Melanie J.
[Show all 25 contributors for this article]
(2024).
The paradox of predictability provides a bridge between micro- and macroevolution.
Journal of Evolutionary Biology.
ISSN 1010-061X.
37(12),
p. 1413–1432.
doi:
10.1093/jeb/voae103.
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The relationship between the evolutionary dynamics observed in contemporary populations (microevolution) and evolution on timescales of millions of years (macroevolution) has been a topic of considerable debate. Historically, this debate centers on inconsistencies between microevolutionary processes and macroevolutionary patterns. Here, we characterize a striking exception: emerging evidence indicates that standing variation in contemporary populations and macroevolutionary rates of phenotypic divergence is often positively correlated. This apparent consistency between micro- and macroevolution is paradoxical because it contradicts our previous understanding of phenotypic evolution and is so far unexplained. Here, we explore the prospects for bridging evolutionary timescales through an examination of this “paradox of predictability.” We begin by explaining why the divergence–variance correlation is a paradox, followed by data analysis to show that the correlation is a general phenomenon across a broad range of temporal scales, from a few generations to tens of millions of years. Then we review complementary approaches from quantitative genetics, comparative morphology, evo-devo, and paleontology to argue that they can help to address the paradox from the shared vantage point of recent work on evolvability. In conclusion, we recommend a methodological orientation that combines different kinds of short-term and long-term data using multiple analytical frameworks in an interdisciplinary research program. Such a program will increase our general understanding of how evolution works within and across timescales.
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Zenil-Ferguson, Rosana & Liow, Lee Hsiang
(2024).
Simpson's tachytely or bradytely? The importance of
quantifying rate uncertainty.
Methods in Ecology and Evolution.
doi:
10.1111/2041-210X.14442.
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The spectacular variation in species forms and richness across space and time can be explored using sophisticated and powerful tools recently developed by evolutionary modellers. In this contribution, we ask if the classic ‘Simpsonian’ view of tachytelic (fast), horotelic (standard) and bradytelic (slow) diversification rates can be distinguished with currently available tools and data. A neglected topic here is the role that the uncertainty of diversification rate estimates plays, where the lack of in-depth uncertainty measures could hinder our ability to confidently suggest differences in speciation or extinction rates in any given comparison. We propose quantifying the relative uncertainty of diversification estimates, to better compare diversification tempo across phylogenies of different sizes and ages. We present three case studies, using the most popular models for diversification rate estimation, with or without fossils, to investigate claims of bradytely or tachytely. Using summary statistics and linear models, we ask if point estimates of diversification rates are comparable across clades. More specifically, we fit a linear model to understand which phylogenetic tree properties (including size and age) may affect the uncertainty of diversification estimates. We found the ‘Goldilocks of uncertainty’: Phylogenies that are young with insufficient tips or that are old increase the uncertainty of diversification estimates. The choice of diversification modelling approach is independent of the pattern of diversification rates decaying exponentially with clade age. In practice, we still cannot confidently compare diversification rates or their variation, due to uncertainties stemming from clade age, sample size and biased sampling. We emphasize the need for researchers to focus on estimating and presenting uncertainty in their estimates. Such uncertainty estimates are currently absent from many publications, limiting our ability to compare the tempo of diversifications across the tree of life. We conclude by proposing solutions and guidelines to encourage new studies for measure uncertainty.
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Gordon, Dennis P.; Quek, Randolph Z B; Orr, Russell John Scott; Waeschenbach, Andrea; Huang, Danwei & Strano, Francesca
[Show all 8 contributors for this article]
(2023).
Morphological diversity and a ribosomal phylogeny of Rhabdopleura (Hemichordata: Graptolithina) from the Western Pacific (Singapore and New Zealand), with implications for a re-evaluation of rhabdopleurid species diversity.
Marine Biodiversity.
ISSN 1867-1616.
53.
doi:
10.1007/s12526-022-01310-3.
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Abstract The recent discovery of Rhabdopleura in Singapore and the chance collecting of fresh material from northern New Zealand (Three Kings Shelf) provided an opportunity to sequence the specimens with an aim to determine their species identity. Phylogeny reconstructions of two new Rhabdopleura taxa based on ribosomal and mitochondrial genes suggest a different identity from known samples, including putative Rhabdopleura annulata , first described from the Three Kings Shelf but sequenced from the Great Barrier Reef. Pairwise distances between rhabdopleurids for the 16S rRNA locus were several magnitudes larger than that of 18S rRNA, and might potentially be a suitable barcoding gene once sufficient samples of conspecifics are collected to determine the barcoding gaps. Type material of R. annulata was re-examined, as well as Rhabdopleura material from eight other New Zealand localities from north of subtropical Raoul Island (Kermadec Ridge) at ~29° S to the subantarctic Campbell Plateau at ~49° S. Six morphological characters, four of them new, were applied to all samples. The findings from morphology suggest (1) the holotype and cotype of R. annulata might not be conspecific; (2) there are 3–4 variants (species?) on the Three Kings Shelf; and (3) there are 2–3 additional variants (species?) elsewhere in the New Zealand region.
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Reitan, Trond; Martino, Emanuela Di & Liow, Lee Hsiang
(2023).
Estimating relative species abundance using fossil data identified to different taxonomic levels.
Ecography.
ISSN 0906-7590.
2024(1).
doi:
10.1111/ecog.06866.
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Site‐occupancy modelling is widely used in ecology for understanding species distribution, habitat‐use and community changes but its application is still limited in paleoecology, where incomplete detection is also routine. Here, we make extensive expansions to an earlier multispecies occupancy model used to estimate the dynamics of relative species abundance in fossil communities. These expansions include incorporating counts of individuals at sites, explicitly allowing for the inclusion of specimens assignable to genus – but not species‐level, a situation common in paleontology, and modelling regional presence/absence. We provide simulations to check the performance of this new model, as well as simulations to quantify the benefits of using individual count data versus subsample occupancy data, and model estimates versus face‐value (raw) estimates, respectively. We also provide an empirical case study using occupancy data from a community of marine benthic colonial animals preserved in the Pleistocene of New Zealand. We find that the new model performs well, especially when it comes to recovering relative abundance dynamics and that it is well worth the effort to both collect individual count data and to include individuals unidentified to species‐level in the site‐occupancy modelling framework. This extended model can be widely applied in paleoecological settings and is necessary when both the average and uncertainty values of relative abundance dynamics need to be robustly estimated.
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Voje, Kjetil L.; Saulsbury, James Gabriel; Starrfelt, Jostein; Latorre, Daniel Varajão; Rojas, Alexis & Kinneberg, Vilde Bruhn
[Show all 10 contributors for this article]
(2023).
Measurement theory and paleobiology.
Trends in Ecology & Evolution.
ISSN 0169-5347.
38,
p. 1165–1176.
doi:
10.1016/j.tree.2023.08.005.
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Measurement theory, a branch of applied mathematics, offers guiding principles for extracting meaning from empirical observations and is applicable to any science involving measurements. Measurement theory is highly relevant in paleobiology because statistical approaches assuming ratio-scaled variables are commonly used on data belonging to nominal and ordinal scale types. We provide an informal introduction to representational measurement theory and argue for its importance in robust scientific inquiry. Although measurement theory is widely applicable in paleobiology research, we use the study of disparity to illustrate measurement theoretical challenges in the quantitative study of the fossil record. Respecting the inherent properties of different measurements enables meaningful inferences about evolutionary and ecological processes from paleontological data.
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Martino, Emanuela Di; Berning, Björn; Gordon, Dennis P; Kuklinski, Piotr; Liow, Lee Hsiang & Ramsfjell, Mali Hamre
[Show all 12 contributors for this article]
(2023).
DeepBryo: A web app for AI-assisted morphometric characterization of cheilostome bryozoans.
Limnology and Oceanography : Methods.
doi:
10.1002/lom3.10563.
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Abstract Bryozoans are becoming an increasingly popular study system in macroevolutionary, ecological, and paleobiological research. Members of this colonial invertebrate phylum display an exceptional degree of division of labor in the form of specialized modules, which allows for the inference of individual allocation of resources to reproduction, defense, and growth using simple morphometric tools. However, morphometric characterizations of bryozoans are notoriously labored. Here, we introduce DeepBryo, a web application for deep‐learning‐based morphometric characterization of cheilostome bryozoans. DeepBryo is capable of detecting objects belonging to six classes and outputting 14 morphological shape measurements for each object. The users can visualize the predictions, check for errors, and directly filter model outputs on the web browser. DeepBryo was trained and validated on a total of 72,412 structures in six different object classes from images of 109 different families of cheilostome bryozoans. The model shows high (> 0.8) recall and precision for zooid‐level structures. Its misclassification rate is low (~ 4%) and largely concentrated in two object classes. The model's estimated structure‐level area, height, and width measurements are statistically indistinguishable from those obtained via manual annotation. DeepBryo reduces the person‐hours required for characterizing individual colonies to less than 1% of the time required for manual annotation. Our results indicate that DeepBryo enables cost‐, labor,‐ and time‐efficient morphometric characterization of cheilostome bryozoans. DeepBryo can greatly increase the scale of macroevolutionary, ecological, taxonomic, and paleobiological analyses, as well as the accessibility of deep‐learning tools for this emerging model system.
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Saulsbury, James; Parins-Fukuchi, C. Tomomi; Wilson, Connor J.; Reitan, Trond & Liow, Lee Hsiang
(2023).
Age-dependent extinction and the neutral theory of biodiversity.
Proceedings of the National Academy of Sciences of the United States of America (PNAS).
ISSN 0027-8424.
121(1).
doi:
10.1073/pnas.2307629121.
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Red Queen (RQ) theory states that adaptation does not protect species from extinction because their competitors are continually adapting alongside them. RQ was founded on the apparent independence of extinction risk and fossil taxon age, but analytical developments have since demonstrated that age-dependent extinction is widespread, usually most intense among young species. Here, we develop ecological neutral theory as a general framework for modeling fossil species survivorship under incomplete sampling. We show that it provides an excellent fit to a high-resolution dataset of species durations for Paleozoic zooplankton and more broadly can account for age-dependent extinction seen throughout the fossil record. Unlike widely used alternative models, the neutral model has parameters with biological meaning, thereby generating testable hypotheses on changes in ancient ecosystems. The success of this approach suggests reinterpretations of mass extinctions and of scaling in eco-evolutionary systems. Intense extinction among young species does not necessarily refute RQ or require a special explanation but can instead be parsimoniously explained by neutral dynamics operating across species regardless of age.
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Reitan, Trond; Ergon, Torbjørn & Liow, Lee Hsiang
(2022).
Relative species abundance and population densities of the past: Developing multispecies occupancy models for fossil data.
Paleobiology.
ISSN 0094-8373.
49(1),
p. 23–38.
doi:
10.1017/pab.2022.17.
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Abstract The number of individuals of species varies, but estimating abundance, given incomplete and biased sampling in both contemporary and fossilized communities, is challenging. Here, we describe a new occupancy model in a hierarchical Bayesian framework with random effects, in which multispecies occupancy and detection are modeled as a means to estimate relative species abundance and relative population densities. The modeling framework is suited for temporal samples of fossil communities with repeated sampling including multiple species with similar preservation potential. We demonstrate our modeling framework using a fossil community of benthic organisms to estimate relative species abundance dynamics and changing relative population densities of focal species in nine (geological) time intervals over 2.3 Myr. We also explore potential explanatory factors (paleoenvironmental proxies) and temporal autocorrelation that could provide extra information on unsampled time intervals. The modeling framework is applicable across a wide range of questions on species-level dynamics in paleoecological community settings.
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Martino, Emanuela Di & Liow, Lee Hsiang
(2022).
Changing allometric relationships among fossil and Recent populations in two colonial species.
Evolution.
ISSN 0014-3820.
76(10),
p. 2424–2435.
doi:
10.1111/evo.14598.
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Allometry is vital for understanding the mechanisms underlying phenotypic evolution. Despite a large body of literature on allometry, studies based on fossil time series are limited for solitary organisms and nonexistent for colonial organisms. Allometric relationships have been found to be relatively constant across Recent populations of the same species, separated by space, but variable among fossil populations separated by thousands of years. How stable are allometric relationships at the module level for colonial organisms? We address this question using two extant species of the cheilostome bryozoan Microporella with fossil records spanning the Pleistocene of New Zealand. We investigate size covariation between feeding modules and three traits with separate functions (reproductive, resource uptake, and defense). We found that within‐population (static) allometry can change on timescales of at least 0.1 million years. These within‐population relationships do not consistently predict overintraspecific evolutionary allometry, which in turn does not predict those estimated at the genus level. Different functional traits are constrained to different extents by module size with defensive traits being the least constrained and most evolvable, compared with reproductive and resource uptake traits. Our study highlights the potential of colonial organisms in understanding the constraints and drivers of long‐term phenotypic change.
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Jain, Sudhanshi S; Gordon, Dennis P; Huang, Danwei; Kuklinski, Piotr & Liow, Lee Hsiang
(2022).
Targeted collections reveal new species and records of Bryozoa and the discovery of Pterobranchia in Singapore.
The Raffles bulletin of zoology.
ISSN 0217-2445.
70,
p. 257–274.
doi:
10.26107/RBZ-2022-0011.
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Orr, Russell John Scott; Martino, Emanuela Di; Ramsfjell, Mali Hamre; Gordon, Dennis P.; Berning, Björn & Chowdhury, Ismael
[Show all 34 contributors for this article]
(2022).
Paleozoic origins of cheilostome bryozoans and their parental care inferred by a new genome-skimmed phylogeny.
Science Advances.
8(13).
doi:
10.1126/sciadv.abm7452.
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Phylogenetic relationships and the timing of evolutionary events are essential for understanding evolution on longer time scales. Cheilostome bryozoans are a group of ubiquitous, species-rich, marine colonial organisms with an excellent fossil record but lack phylogenetic relationships inferred from molecular data. We present genome-skimmed data for 395 cheilostomes and combine these with 315 published sequences to infer relationships and the timing of key events among c. 500 cheilostome species. We find that named cheilostome genera and species are phylogenetically coherent, rendering fossil or contemporary specimens readily delimited using only skeletal morphology. Our phylogeny shows that parental care in the form of brooding evolved several times independently but was never lost in cheilostomes. Our fossil calibration, robust to varied assumptions, indicates that the cheilostome lineage and parental care therein could have Paleozoic origins, much older than the first known fossil record of cheilostomes in the Late Jurassic.
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Kopperud, Bjørn Tore; Lidgard, Scott & Liow, Lee Hsiang
(2022).
Enhancing georeferenced biodiversity inventories: automated information extraction from literature records reveal the gaps.
PeerJ.
10,
p. 1–22.
doi:
10.7717/peerj.13921.
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We use natural language processing (NLP) to retrieve location data for cheilostome bryozoan species (text-mined occurrences (TMO)) in an automated procedure. We compare these results with data combined from two major public databases (DB): the Ocean Biodiversity Information System (OBIS), and the Global Biodiversity Information Facility (GBIF). Using DB and TMO data separately and in combination, we present latitudinal species richness curves using standard estimators (Chao2 and the Jackknife) and range-through approaches. Our combined DB and TMO species richness curves quantitatively document a bimodal global latitudinal diversity gradient for extant cheilostomes for the first time, with peaks in the temperate zones. A total of 79% of the georeferenced species we retrieved from TMO ( N = 1,408) and DB ( N = 4,549) are non-overlapping. Despite clear indications that global location data compiled for cheilostomes should be improved with concerted effort, our study supports the view that many marine latitudinal species richness patterns deviate from the canonical latitudinal diversity gradient (LDG). Moreover, combining online biodiversity databases with automated information retrieval from the published literature is a promising avenue for expanding taxon-location datasets.
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Liow, Lee Hsiang; Uyeda, Josef & Hunt, Gene
(2022).
Cross-disciplinary information for understanding macroevolution.
Trends in Ecology & Evolution.
ISSN 0169-5347.
doi:
10.1016/j.tree.2022.10.013.
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Many different macroevolutionary models can produce the same observations. Despite efforts in building more complex and realistic models, it may still be difficult to distinguish the processes that have generated the biodiversity we observe. In this opinion we argue that we can make new progress by reaching out across disciplines, relying on independent data and theory to constrain macroevolutionary inference. Using mainly paleontological insights and data, we illustrate how we can eliminate less plausible or implausible models, and/or parts of parameter space, while applying comparative phylogenetic approaches. We emphasize that such cross-disciplinary insights and data can be drawn between many other disciplines relevant to macroevolution. We urge cross-disciplinary training, and collaboration using common-use databases as a platform for increasing our understanding.
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Orr, Russell John Scott; Martino, Emanuela Di; Gordon, Dennis P.; Ramsfjell, Mali Hamre; Mello, Hannah & Smith, Abigail M.
[Show all 7 contributors for this article]
(2021).
A broadly resolved molecular phylogeny of New Zealand cheilostome bryozoans as a framework for hypotheses of morphological evolution.
Molecular Phylogenetics and Evolution.
ISSN 1055-7903.
161.
doi:
10.1016/j.ympev.2021.107172.
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Larger molecular phylogenies based on ever more genes are becoming commonplace with the advent of cheaper and more streamlined sequencing and bioinformatics pipelines. However, many groups of inconspicuous but no less evolutionarily or ecologically important marine invertebrates are still neglected in the quest for understanding species- and higher-level phylogenetic relationships. Here, we alleviate this issue by presenting the molecular sequences of 165 cheilostome bryozoan species from New Zealand waters. New Zealand is our geographic region of choice as its cheilostome fauna is taxonomically, functionally and ecologically diverse, and better characterized than many other such faunas in the world. Using this most taxonomically broadly-sampled and statistically-supported cheilostome phylogeny comprising 214 species, when including previously published sequences, and 17 genes (2 nuclear and 15 mitochondrial) we tested several existing systematic hypotheses based solely on morphological observations. We find that lower taxonomic level hypotheses (species and genera) are robust while our inferred trees did not reflect current higher-level systematics (family and above), illustrating a general need for the rethinking of current hypotheses. To illustrate the utility of our new phylogeny, we reconstruct the evolutionary history of frontal shields (i.e., a calcified body-wall layer in ascus-bearing cheilostomes) and ask if its presence has any bearing on the diversification rates of cheilostomes.
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Love, Alan; Grabowski, Mark Walter; Houle, David; Liow, Lee Hsiang; Porto, Arthur Guimaraes Carvalho & Tsuboi, Masahito
[Show all 8 contributors for this article]
(2021).
Evolvability in the fossil record.
Paleobiology.
ISSN 0094-8373.
p. 1–24.
doi:
10.1017/pab.2021.36.
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Abstract The concept of evolvability—the capacity of a population to produce and maintain evolutionarily relevant variation—has become increasingly prominent in evolutionary biology. Paleontology has a long history of investigating questions of evolvability, but paleontological thinking has tended to neglect recent discussions, because many tools used in the current evolvability literature are challenging to apply to the fossil record. The fundamental difficulty is how to disentangle whether the causes of evolutionary patterns arise from variational properties of traits or lineages rather than being due to selection and ecological success. Despite these obstacles, the fossil record offers unique and growing sources of data that capture evolutionary patterns of sustained duration and significance otherwise inaccessible to evolutionary biologists. Additionally, there exist a variety of strategic possibilities for combining prominent neontological approaches to evolvability with those from paleontology. We illustrate three of these possibilities with quantitative genetics, evolutionary developmental biology, and phylogenetic models of macroevolution. In conclusion, we provide a methodological schema that focuses on the conceptualization, measurement, and testing of hypotheses to motivate and provide guidance for future empirical and theoretical studies of evolvability in the fossil record.
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Martino, Emanuela Di & Liow, Lee Hsiang
(2021).
Larger offspring associated with lower temperatures across species of Microporella, a widespread colonial invertebrate.
Marine Ecology Progress Series.
ISSN 0171-8630.
662,
p. 1–13.
doi:
10.3354/meps13656.
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Among life history traits, offspring size has one of the most direct impacts on fitness, influencing growth, recruitment and survival of the individual, therefore affecting population, and ultimately macroevolutionary outcomes. Despite its ecological and evolutionary importance, little is known about how offspring size varies in lineages over macroevolutionary timescales, especially for colonial organisms. Here, we use the cheilostome bryozoan genus Microporella to investigate variation in offspring size over the history of the lineage. The genus Microporella is species-rich, cosmopolitan, has a calcified skeleton (and is hence readily preserved in the fossil record), and is a brooder. The brood structure (ovicell) reliably reflects the space occupied by a larva and hence ovicell size is a good proxy for offspring size. Using a suite of biotic and abiotic factors, we ask what best explains offspring/larval size variation in contemporary and fossil species of Microporella , and how offspring/larval size changes through the millions of years of the history of the lineage. We find that offspring size is affected by a combination of module size and water temperature (or latitude when fossil species are included), while fecundity and levels of nutrients have a weak to no effect on this life history trait. Among Microporella species, descendant species are statistically more likely to have larger offspring than their putative ancestors, with the size difference between species pairs little explained by temporal latitudinal shifts. Our results suggest that both contemporary ecological controls and historical considerations are important in understanding life history trait evolution.
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Lidgard, Scott; Martino, Emanuela Di; Zagorszek, Kamil & Liow, Lee Hsiang
(2021).
When fossil clades ‘compete’: local dominance, global diversification dynamics and causation.
Proceedings of the Royal Society of London. Biological Sciences.
ISSN 0962-8452.
288,
p. 1–10.
doi:
10.1098/rspb.2021.1632.
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Examining the supposition that local-scale competition drives macroevolutionary patterns has become a familiar goal in fossil biodiversity studies. However, it is an elusive goal, hampered by inadequate confirmation of ecological equivalence and interactive processes between clades, patchy sampling, few comparative analyses of local species assemblages over long geological intervals, and a dearth of appropriate statistical tools. We address these concerns by reevaluating one of the classic examples of clade displacement in the fossil record, in which cheilostome bryozoans surpass the once dominant cyclostomes. Here, we analyse a newly expanded and vetted compilation of 40 190 fossil species occurrences to estimate cheilostome and cyclostome patterns of species proportions within assemblages, global genus richness and genus origination and extinction rates while accounting for sampling. Comparison of time-series models using linear stochastic differential equations suggests that inter-clade genus origination and extinction rates are causally linked to each other in a complex feedback relationship rather than by simple correlations or unidirectional relationships, and that these rates are not causally linked to changing within-assemblage proportions of cheilostome versus cyclostome species.
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Martino, Emanuela Di & Liow, Lee Hsiang
(2021).
Trait-fitness associations do not predict within-species phenotypic evolution over 2 million years.
Proceedings of the Royal Society of London. Biological Sciences.
ISSN 0962-8452.
288(1943),
p. 1–9.
doi:
10.1098/rspb.2020.2047.
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Long-term patterns of phenotypic change are the cumulative results of tens of thousands to millions of years of evolution. Yet, empirical and theoretical studies of phenotypic selection are largely based on contemporary populations. The challenges in studying phenotypic evolution, in particular trait–fitness associations in the deep past, are barriers to linking micro- and macroevolution. Here, we capitalize on the unique opportunity offered by a marine colonial organism commonly preserved in the fossil record to investigate trait–fitness associations over 2 Myr. We use the density of female polymorphs in colonies of Antartothoa tongima as a proxy for fecundity, a fitness component, and investigate multivariate signals of trait–fitness associations in six time intervals on the backdrop of Pleistocene climatic shifts. We detect negative trait–fitness associations for feeding polymorph (autozooid) sizes, positive associations for autozooid shape but no particular relationship between fecundity and brood chamber size. In addition, we demonstrate that long-term trait patterns are explained by palaeoclimate (as approximated by ∂18O), and to a lesser extent by ecological interactions (i.e. overgrowth competition and substrate crowding). Our analyses show that macroevolutionary outcomes of trait evolution are not a simple scaling-up from the trait–fitness associations.
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Martino, Emanuela Di; Liow, Lee Hsiang; Perkins, Tom; Portell, Roger W. & Taylor, Paul D.
(2020).
Sneaking up on ‘enemies’: alleviating inherent disadvantages in competitive outcomes in a nearly 3-million-year-old palaeocommunity from Florida, USA.
Lethaia: An International Journal of Palaeontology and Stratigraphy.
ISSN 0024-1164.
53(4),
p. 553–562.
doi:
10.1111/let.12376.
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Bryozoans offer one of the few systems in which competitive interactions for living space can be studied in the fossil record. Here, we describe the outcome of competitive overgrowths in a 3‐million‐year‐old bryozoan palaeocommunity encrusting shells of the bivalve Anomia simplex from the lower Tamiami Formation in Florida (upper Pliocene, Piacenzian). We found that win–lose overgrowths are more common than stand‐offs in interspecific encounters, while stand‐offs are more common than win–lose overgrowths in intraspecific encounters. We observed more intraspecific encounters and fewer interspecific interactions than expected under a null hypothesis, suggesting that bryozoans of the same species are likely to be clustered. For some species, intraspecific encounters are more likely to result in the apparent fusion of the two colonies, with the development of rows of kenozooids along the contact edge, probably reflecting relatively low dispersal. We also identified some clear winners and some clear losers. A negative correlation was found between the number of colonies observed and the probability of winning for a species, resulting in a dominance of loser species in the assemblage, a pattern previously described as typical for early colonizers of hard substrates. Our results also confirm the finding of earlier studies that having large zooids and, subordinately, multilayered growth are key traits for success in overgrowth competition, with angle of encounter also having an effect for both poor and good competitors that take advantage of ‘attacking’ colonies of other species from the rear and the flank.
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Franeck, Franziska & Liow, Lee Hsiang
(2020).
Did hard substrate taxa diversify prior to the Great Ordovician Biodiversification Event?
Palaeontology.
ISSN 0031-0239.
63(4),
p. 675–687.
doi:
10.1111/pala.12489.
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The Great Ordovician Biodiversification Event (GOBE) refers to one of the greatest increases in biodiversity during the Phanerozoic. Recent studies have shown that this taxonomic increase can be attributed to elevated origination rates around the Dapingian–Darriwilian boundary in the Middle Ordovician, while extinction rates stayed relatively constant throughout the Ordovician. Even though this global pattern of origination and extinction appears similar across diverse groups and geographical areas, earlier studies suggested that hard substrate taxa may have diversified prior to the GOBE, during the Early Ordovician. Here, we quantify Ordovician diversification dynamics of hard substrate taxa while simultaneously accounting for temporally varying sampling probabilities. Diversification rates of hard substrate taxa, both as a whole and when analysed as separate groups, appear to be very similar to those of free‐living benthic taxa. The observation that the diversification dynamics of many different taxonomic and ecological groups show the same temporal pattern, suggests a common cause of Ordovician diversification dynamics.
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Orr, Russell; Sannum, Maja Margret; Boessenkool, Sanne; Martino, Emanuela Di; Gordon, Dennis & Mello, Hannah
[Show all 10 contributors for this article]
(2020).
A molecular phylogeny of historical and contemporary specimens of an under‐studied micro‐invertebrate group.
Ecology and Evolution.
11(1),
p. 309–320.
doi:
10.1002/ece3.7042.
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Resolution of relationships at lower taxonomic levels is crucial for answering many evolutionary questions, and as such, sufficiently varied species representation is vital. This latter goal is not always achievable with relatively fresh samples. To alleviate the difficulties in procuring rarer taxa, we have seen increasing utilization of historical specimens in building molecular phylogenies using high throughput sequencing. This effort, however, has mainly focused on large‐bodied or well‐studied groups, with small‐bodied and under‐studied taxa under‐prioritized. Here, we utilize both historical and contemporary specimens, to increase the resolution of phylogenetic relationships among a group of under‐studied and small‐bodied metazoans, namely, cheilostome bryozoans. In this study, we pioneer the sequencing of air‐dried cheilostomes, utilizing a recently developed library preparation method for low DNA input. We evaluate a de novo mitogenome assembly and two iterative methods, using the sequenced target specimen as a reference for mapping, for our sequences. In doing so, we present mitochondrial and ribosomal RNA sequences of 43 cheilostomes representing 37 species, including 14 from historical samples ranging from 50 to 149 years old. The inferred phylogenetic relationships of these samples, analyzed together with publicly available sequence data, are shown in a statistically well‐supported 65 taxa and 17 genes cheilostome tree, which is also the most broadly sampled and largest to date. The robust phylogenetic placement of historical samples whose contemporary conspecifics and/or congenerics have been sequenced verifies the appropriateness of our workflow and gives confidence in the phylogenetic placement of those historical samples for which there are no close relatives sequenced. The success of our workflow is highlighted by the circularization of a total of 27 mitogenomes, seven from historical cheilostome samples. Our study highlights the potential of utilizing DNA from micro‐invertebrate specimens stored in natural history collections for resolving phylogenetic relationships among species.
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Franeck, Franziska & Liow, Lee Hsiang
(2019).
Dissecting the paleocontinental and paleoenvironmental dynamics of the great Ordovician biodiversification.
Paleobiology.
ISSN 0094-8373.
45(2),
p. 221–234.
doi:
10.1017/pab.2019.4.
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The Ordovician was a time of drastic biological and geological change. Previous work has suggested that there was a dramatic increase in global diversity during this time, but also has indicated that regional dynamics and dynamics in specific environments might have been different. Here, we contrast two paleocontinents that have different geological histories through the Ordovician, namely Laurentia and Baltica. The first was situated close to the equator throughout the whole Ordovician, while the latter has traversed tens of latitudes during the same time. We predict that Baltica, which was under long-term environmental change, would show greater average and interval-to-interval origination and extinction rates than Laurentia. In addition, we are interested in the role of the environment in which taxa originated, specifically, the patterns of onshore–offshore dynamics of diversification, where onshore and offshore areas represent high-energy and low-energy environments, respectively. Here, we predict that high-energy environments might be more conducive for originations.Our new analyses show that the global Ordovician spike in genus richness from the Dapingian to the Darriwilian Stage resulted from a very high origination rate at the Dapingian/Darriwilian boundary, while the extinction rate remained low. We found substantial interval-to-interval variation in the origination and extinction rates in Baltica and Laurentia, but the probabilities of origination and extinction are somewhat higher in Baltica than Laurentia. Onshore and offshore areas have largely indistinguishable origination and extinction rates, in contradiction to our predictions. The global spike in origination rates at the Dapingian/Darriwilian boundary is apparent in Baltica, Laurentia, and onshore and offshore areas, and abundant variability in diversification rates is apparent over other time intervals for these paleocontinents and paleoenvironments. This observation hints at global mechanisms for the spike in origination rates at the Dapingian/Darriwilian boundary but a domination of more regional and local mechanisms over other time intervals in the Ordovician.
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Liow, Lee Hsiang; Reitan, Trond; Voje, Kjetil L.; Taylor, Paul D. & Martino, Emanuela Di
(2019).
Size, weapons, and armor as predictors of competitive outcomes in fossil and contemporary marine communities.
Ecological Monographs.
ISSN 0012-9615.
p. 1–15.
doi:
10.1002/ecm.1354.
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Orr, Russell; Haugen, Marianne Nilsen; Berning, Björn; Bock, Phil; Cumming, Robyn L. & Florence, Wayne
[Show all 14 contributors for this article]
(2019).
A genome-skimmed phylogeny of a widespread bryozoan family, Adeonidae.
BMC Evolutionary Biology.
19(235).
doi:
10.1186/s12862-019-1563-4.
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Background Understanding the phylogenetic relationships among species is one of the main goals of systematic biology. Simultaneously, credible phylogenetic hypotheses are often the first requirement for unveiling the evolutionary history of traits and for modelling macroevolutionary processes. However, many non-model taxa have not yet been sequenced to an extent such that statistically well-supported molecular phylogenies can be constructed for these purposes. Here, we use a genome-skimming approach to extract sequence information for 15 mitochondrial and 2 ribosomal operon genes from the cheilostome bryozoan family, Adeonidae, Busk, 1884, whose current systematics is based purely on morphological traits. The members of the Adeonidae are, like all cheilostome bryozoans, benthic, colonial, marine organisms. Adeonids are also geographically widely-distributed, often locally common, and are sometimes important habitat-builders. Results We successfully genome-skimmed 35 adeonid colonies representing 6 genera (Adeona, Adeonellopsis, Bracebridgia, Adeonella, Laminopora and Cucullipora). We also contributed 16 new, circularised mitochondrial genomes to the eight previously published for cheilostome bryozoans. Using the aforementioned mitochondrial and ribosomal genes, we inferred the relationships among these 35 samples. Contrary to some previous suggestions, the Adeonidae is a robustly supported monophyletic clade. However, the genera Adeonella and Laminopora are in need of revision: Adeonella is polyphyletic and Laminopora paraphyletically forms a clade with some Adeonella species. Additionally, we assign a sequence clustering identity using cox1 barcoding region of 99% at the species and 83% at the genus level. Conclusions We provide sequence data, obtained via genome-skimming, that greatly increases the resolution of the phylogenetic relationships within the adeonids. We present a highly-supported topology based on 17 genes and substantially increase availability of circularised cheilostome mitochondrial genomes, and highlight how we can extend our pipeline to other bryozoans.
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Reitan, Trond & Liow, Lee Hsiang
(2019).
layeranalyzer: inferring correlative and causal connections from time series data in R.
Methods in Ecology and Evolution.
10(12),
p. 2183–2188.
doi:
10.1111/2041-210X.13299.
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1. Distinguishing correlative and causal connections among time series is an important challenge in evolutionary biology, ecology, macroevolution and palaeobiology. 2. Here, we present layeranalyzer, an r package that uses linear stochastic differential equations as a tool for parametrically describing evolutionary and ecological processes and for modelling temporal correlation and Granger causality between two or more time series. 3. We describe the basic functions in layeranalyzer and briefly discuss modelling strategies by demonstrating our tool with three disparate case studies. First, we model a single time series of phenotypic evolution in a bird species; second, we extract cyclical connections in the well‐known hare‐lynx dataset; third, we infer the correlative and causal connections among the genus origination and extinction rates of brachiopods and bivalves. 4. We summarize the advantages and limitations of using linear stochastic differential equations and layeranalyzer for studying correlative and causal connections.
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Kopperud, Bjørn Tore; Lidgard, Scott & Liow, Lee Hsiang
(2019).
Text-mined fossil biodiversity dynamics using machine learning.
Proceedings of the Royal Society of London. Biological Sciences.
ISSN 0962-8452.
286(1901).
doi:
10.1098/rspb.2019.0022.
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Documented occurrences of fossil taxa are the empirical foundation for understanding large-scale biodiversity changes and evolutionary dynamics in deep time. The fossil record contains vast amounts of understudied taxa. Yet the compilation of huge volumes of data remains a labour-intensive impediment to a more complete understanding of Earth’s biodiversity history. Even so, many occurrence records of species and genera in these taxa can be uncovered in the palaeontological literature. Here, we extract observations of fossils and their inferred ages from unstructured text in books and scientific articles using machine-learning approaches. We use Bryozoa, a group of marine invertebrates with a rich fossil record, as a case study. Building on recent advances in computational linguistics, we develop a pipeline to recognize taxonomic names and geologic time intervals in published literature and use supervised learning to machine-read whether the species in question occurred in a given age interval. Intermediate machine error rates appear comparable to human error rates in a simple trial, and resulting genus richness curves capture the main features of published fossil diversity studies of bryozoans. We believe our automated pipeline, that greatly reduced the time required to compile our dataset, can help others compile similar data for other taxa.
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Liow, Lee Hsiang & Taylor, Paul D.
(2019).
Cope's Rule in a modular organism: Directional evolution without an overarching macroevolutionary trend.
Evolution.
ISSN 0014-3820.
73(9),
p. 1863–1872.
doi:
10.1111/evo.13800.
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Cope's Rule describes increasing body size in evolutionary lineages through geological time. This pattern has been documented in unitary organisms but does it also apply to module size in colonial organisms? We address this question using 1169 cheilostome bryozoans ranging through the entire 150 million years of their evolutionary history. The temporal pattern evident in cheilostomes as a whole shows no overall change in zooid (module) size. However, individual subclades show size increases: within a genus, younger species often have larger zooids than older species. Analyses of (paleo)latitudinal shifts show that this pattern cannot be explained by latitudinal effects (Bergmann's Rule) coupled with younger species occupying higher latitudes than older species (an “out of the tropics” hypothesis). While it is plausible that size increase was linked to the advantages of large zooids in feeding, competition for trophic resources and living space, other proposed mechanisms for Cope's Rule in unitary organisms are either inapplicable to cheilostome zooid size or cannot be evaluated. Patterns and mechanisms in colonial organisms cannot and should not be extrapolated from the better‐studied unitary organisms. And even if macroevolution simply comprises repeated rounds of microevolution, evolutionary processes occurring within lineages are not always detectable from macroevolutionary patterns.
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Orr, Russell; Waeschenbach, Andrea; Enevoldsen, Emily; Boeve, Jeroen Pieter; Haugen, Marianne Nilsen & Voje, Kjetil L.
[Show all 11 contributors for this article]
(2018).
Bryozoan genera Fenestrulina and Microporella no longer confamilial; multi-gene phylogeny supports separation.
Zoological Journal of the Linnean Society.
ISSN 0024-4082.
p. 1–10.
doi:
10.1093/zoolinnean/zly055.
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Bryozoans are a moderately diverse, mostly marine phylum with a fossil record extending to the Early Ordovician. Compared to other phyla, little is known about their phylogenetic relationships at both lower and higher taxonomic levels. Hence, an effort is being made to elucidate their phylogenetic relationships. Here, we present newly sequenced nuclear and mitochondrial genes for 21 cheilostome bryozoans. Combining these data with existing orthologous molecular data, we focus on reconstructing the phylogenetic relationships of Fenestrulina and Microporella, two species-rich genera. They are currently placed in Microporellidae, defined by having a semicircular primary orifice and a proximal ascopore. Our six-gene phylogenetic analysis reveals that the genera Fenestrulina and Microporella are each monophyletic, with the sister clade to Microporella comprising non-microporellids. Our result hence supports the reinstatement of the family Fenestrulinidae Jullien, 1888 for Fenestrulina and genera with comparable frontal shield and ooecial morphologies. Our well-supported phylogeny, based on independent molecular data, lends credit to existing phylogenetic hypotheses based on morphological observations but does not conform to the current classification of these bryozoans. This illustrates the general need for a rethink of bryozoan higher level systematics, ideally based on both morphological and molecular data.
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Hannisdal, Bjarte & Liow, Lee Hsiang
(2018).
Causality from palaeontological time series.
Palaeontology.
ISSN 0031-0239.
61(4),
p. 495–509.
doi:
10.1111/pala.12370.
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As custodians of deep time, palaeontologists have an obligation to seek the causes and consequences of long‐term evolutionary trajectories and the processes of ecosystem assembly and collapse. Building explicit process models on the relevant scales can be fraught with difficulties, and causal inference is typically limited to patterns of association. In this review, we discuss some of the ways in which causal connections can be extracted from palaeontological time series and provide an overview of three recently developed analytical frameworks that have been applied to palaeontological questions, namely linear stochastic differential equations, convergent cross mapping and transfer entropy. We outline how these methods differ conceptually, and in practice, and point to available software and worked examples. We end by discussing why a paradigm of dynamical causality is needed to decipher the messages encrypted in palaeontological patterns.
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Toljagic, Olja; Voje, Kjetil L.; Matschiner, Michael; Liow, Lee Hsiang & Hansen, Thomas F
(2018).
Millions of Years Behind: Slow Adaptation of Ruminants to Grasslands.
Systematic Biology.
ISSN 1063-5157.
67(1),
p. 145–157.
doi:
10.1093/sysbio/syx059.
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Voje, Kjetil L.; Starrfelt, Jostein & Liow, Lee Hsiang
(2018).
Model adequacy and microevolutionary explanations for stasis in the fossil record.
The American Naturalist.
ISSN 0003-0147.
191(4),
p. 509–523.
doi:
10.1086/696265.
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Long-term phenotypic stasis is frequently observed in the fossil record, but not readily predicted from microevolutionary theory. To test competing explanations for stasis on macroevolutionary timescales we need reliably estimated parameters from appropriate evolutionary models that adequately describe the evolutionary trait dynamics. Here, we develop tests to assess the adequacy of the most commonly used stasis model in evolutionary biology and apply them to time series of phenotypic traits from fossil lineages. Of the 572 fossil time series we analyzed from the literature, 263 time series showed a better fit to the stasis model relative to alternative models, but only 172 of those fitted the stasis model in both relative and absolute terms. The estimated trait variances from these 172 time series do not correlate with rough proxies of effective population size. Our preliminary investigation of the fixed-optimum hypothesis hence fails to give empirical support to the idea that genetic drift around a constant trait optimum is an explanation for stasis in the fossil record. We argue that optima following stationary processes on the adaptive landscape is a viable hypothesis for stasis that needs further investigation. We end by discussing how investigations of model adequacy can be a valuable approach for increasing our understanding of the dynamics of the adaptive landscape on macroevolutionary timescales.
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Hannisdal, Bjarte; Haaga, Kristian Agasøster; Reitan, Trond; Castro, David Diego & Liow, Lee Hsiang
(2017).
Common species link global ecosystems to climate change: Dynamical evidence in the planktonic fossil record.
Proceedings of the Royal Society of London. Biological Sciences.
ISSN 0962-8452.
284(1858),
p. 1–9.
doi:
10.1098/rspb.2017.0722.
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Common species shape the world around us, and changes in their commonness signify large-scale shifts in ecosystem structure and function. However, our understanding of long-term ecosystem response to environmental forcing in the deep past is centred on species richness, neglecting the disproportional impact of common species. Here, we use common and widespread species of planktonic foraminifera in deep-sea sediments to track changes in observed global occupancy (proportion of sampled sites at which a species is present and observed) through the turbulent climatic history of the last 65 Myr. Our approach is sensitive to relative changes in global abundance of the species set and robust to factors that bias richness estimators. Using three independent methods for detecting causality, we show that the observed global occupancy of planktonic foraminifera has been dynamically coupled to past oceanographic changes captured in deep-ocean temperature reconstructions. The causal inference does not imply a direct mechanism, but is consistent with an indirect, time-delayed causal linkage. Given the strong quantitative evidence that a dynamical coupling exists, we hypothesize that mixotrophy (symbiont hosting) may be an ecological factor linking the global abundance of planktonic foraminifera to long-term climate changes via the relative extent of oligotrophic oceans.
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Struck, Torsten H; Feder, Jeffrey L.; Bendiksby, Mika; Birkeland, Siri; Oliveira, Josè Cerca De & Gusarov, Vladimir
[Show all 13 contributors for this article]
(2017).
Finding Evolutionary Processes Hidden in Cryptic Species.
Trends in Ecology & Evolution.
ISSN 0169-5347.
33(3),
p. 153–163.
doi:
10.1016/j.tree.2017.11.007.
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Cryptic species could represent a substantial fraction of biodiversity. However, inconsistent definitions and taxonomic treatment of cryptic species prevent informed estimates of their contribution to biodiversity and impede our understanding of their evolutionary and ecological significance. We propose a conceptual framework that recognizes cryptic species based on their low levels of phenotypic (morphological) disparity relative to their degree of genetic differentiation and divergence times as compared to non-cryptic species. We discuss how application of a more rigorous definition of cryptic species in taxonomic practice will lead to more accurate estimates of their prevalence in nature, better understanding of their distribution patterns on the tree of life, and increased abilities to resolve the processes underlying their evolution.
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Yehu, Moran,; M, Coelho, Susana; G, Ettema, Thijs J; Cedric, Feschotte,; Martin, Kaltenpoth, & Abderrahman, Khila,
[Show all 14 contributors for this article]
(2026).
EMBO Press co-evolves with molecular ecology and evolutionary biology.
EMBO Journal.
ISSN 0261-4189.
45,
p. 1815–1817.
doi:
10.1038/s44318-026-00723-1.
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Molecular ecology and evolution are central to understanding how biological systems function, interact, and diversify. A special issue of this journal reflects the growing synergy of molecular, genomic and cell biology with ecological and evolutionary reasoning. Accordingly, EMBO Press is recalibrating its editorial practices to better support studies embedded in ecological and evolutionary contexts. Molecular ecology and evolution are central to understanding how biological systems function, interact, and diversify. A special issue of this journal reflects the growing synergy of molecular, genomic and cell biology with ecological and evolutionary reasoning. Accordingly, EMBO Press is recalibrating its editorial practices to better support studies embedded in ecological and evolutionary contexts.
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Liow, Lee Hsiang
(2025).
Drivers of diversification rates and ecological changes: stories of brachiopods, bivalves and coccolithophores.
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Saulsbury, James; Parins-Fukuchi, C. Tomomi; Wilson, Connor J.; Reitan, Trond & Liow, Lee Hsiang
(2025).
Reply to Johnson: Holistic evaluation of ecological models in paleobiology.
Proceedings of the National Academy of Sciences of the United States of America (PNAS).
ISSN 0027-8424.
122(10).
doi:
10.1073/pnas.2415303122.
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Liow, Lee Hsiang; Feng, Yan & Song, Haijun
(2024).
Extinction vulnerability of foraminiferans of differing body sizes.
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Throughout Earth’s history, numerous extinction events have occurred, with mass extinctions
revealing a notable pattern: different biological groups experience distinct extinction risks.
Palaeontologists have long been curious about which traits determine the likelihood of species
extinction. This study investigates the role of three specific traits—body size, species richness,
and geographic range—in influencing the extinction risk of foraminifera across a total of 12,701
specimens. The results highlight body size as a critical determinant of extinction risk, with larger
foraminifera exhibiting heightened vulnerability. This size selectivity was particularly pronounced
during the Guadalupian-Lopingian (259.51 Ma), Permian-Triassic (251.902 Ma), and CretaceousPalaeogene (66.1 Ma) mass extinctions. One possible explanation for this pattern is the increased
difficulty of oxygen diffusion within larger foraminifera, which may have made them more
susceptible to extinction. In contrast, species richness and geographic range showed no statistically
significant effects on extinction risk. We hence propose a hypothesis to explain size-selective
extinction and the Lilliput effect in diffusion-dependent organisms in past extinctions, which may
also apply to future anoxic conditions. We also use newly compiled data to explore the temporal
patterns of foraminiferan size evolution beyond mass extinction events.
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Liow, Lee Hsiang
(2024).
Two million years of biotic interactions & phenotypic evolution: an integrated view from the New Zealand Pleistocene record.
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Liow, Lee Hsiang
(2024).
Contrasting trait-fitness associations
& models of phenotypic change
using fossil cheilostome bryozoans.
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Ramsfjell, Mali Hamre; Martino, Emanuela Di; Kongshavn, Katrine; Kongsrud, Jon Anders; Bakken, Torkild & Liow, Lee Hsiang
(2024).
NorDigBryo - Digitization of Norwegian Bryozoa.
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Liow, Lee Hsiang
(2024).
From biotic interactions to phenotypic evolution:
a view from the fossil record (at Penn State).
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Ramsfjell, Mali Hamre; Martino, Emanuela Di; Kongshavn, Katrine; Kongsrud, Jon Anders; Bakken, Torkild & Liow, Lee Hsiang
(2024).
NorDigBryo – digitization of Norwegian Bryozoa.
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Penny, Amelia; Liow, Lee Hsiang & other, working group authors 30
(2024).
Analysis of neoecological and palaeoecological assemblage time series shows that species-time relationships are not scale-invariant.
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Wilson, Connor J.; Reitan, Trond & Liow, Lee Hsiang
(2023).
Using linear stochastic differential equations to guide the search for the drivers of marine origination and extinction.
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Liow, Lee Hsiang; Reitan, Trond & Martino, Emanuela Di
(2023).
ESTIMATING COMPETITION AND ITS EFFECTS OVER MACROEVOLUTIONARY TIME SCALES.
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Saulsbury, James; Piwoni-Piórewicz, Anna; Kuklinski, Piotr; Martino, Emanuela Di & Liow, Lee Hsiang
(2023).
Phylogenetic and paleontological perspectives on the evolution of skeletal mineralogy in cheilostome bryozoans.
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Martino, Emanuela Di; Porto, Arthur & Liow, Lee Hsiang
(2023).
A cheilostome bryozoan story of fitness and phenotypes across two million years.
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Martino, Emanuela Di & Liow, Lee Hsiang
(2022).
Changing allometric relationships among fossil and Recent populations of two species of Microporella from New Zealand.
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Martino, Emanuela Di & Liow, Lee Hsiang
(2022).
A time-calibrated molecular phylogeny of cheilostome bryozoans
to quantify previously inferred macroevolutionary relationships.
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Saulsbury, James Gabriel; Parins-Fukuchi, Caroline; Reitan, Trond; Wilson, Connor J. & Liow, Lee Hsiang
(2022).
AGE-DEPENDENT EXTINCTION AND THE NEUTRAL THEORY OF BIODIVERSITY.
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Tomasovych, A. & Liow, Lee Hsiang
(2022).
SCALE DEPENDENCY OF TEMPORAL TURNOVER IN COMMUNITY COMPOSITION IN THE FOSSIL RECORD.
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Smith, Jansen & Liow, Lee Hsiang
(2022).
BIODEEPTIME VERSION 1.0: A NEW DATABASE OF BIODIVERSITY TIME SERIES FOR THE CENOZOIC.
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Martino, Emanuela Di & Liow, Lee Hsiang
(2021).
Static and evolutionary allometry in multiple temporal populations of closely related cheilostome bryozoan species.
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Martino, Emanuela Di & Liow, Lee Hsiang
(2021).
Static and evolutionary allometry in multiple temporal populations of closely related cheilostome bryozoan species.
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Liow, Lee Hsiang
(2021).
From “minor phylum” to the Drosophila of macroevolution: elevating Bryozoa by integrating disparate tools and approaches.
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Liow, Lee Hsiang
(2021).
An integrated view of diversification, ecology, life history traits and paleoenvironment: bryozoans as a model.
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Published
Nov. 3, 2010 3:30 PM
- Last modified
Mar. 11, 2011 3:49 PM