Lee Hsiang Liow

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).

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 numbers of cheilostome bryozoan species have increased relative to 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 come 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 advantage in higher latitudes, even as cheilostome bryozoan species numbers dominate globally.

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.

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.

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 little 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 8 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 s ince their split with other cheilostome bryozoans. These fusions were enriched with long terminal repeat (LTR) 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.

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 10 ¹ to 10 ⁵ 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.

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.

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 50 ^th 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.

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.