Evolutionary History Research Articles

First fossil record of false stag beetles (Coleoptera: Scarabaeoidea: Diphyllostomatidae): Evolutionary and biogeographical implications

The monogeneric scarabaeoid family Diphyllostomatidae contains only three extant false stag beetle species, all of which are restricted to California, USA. In this study, a fossil specimen newly found in mid-Cretaceous Kachin amber of northern Myanmar is putatively assigned to this family, here described as Prodiphyllostoma inexpectatum gen. et sp. nov. The discovery of this rare scarabaeoid as a Mesozoic amber inclusion from Myanmar is significant in consideration of the paleobiogeography and evolutionary history of this family.

Paleoneurology of stem palaeognaths clarifies the plesiomorphic condition of the crown bird central nervous system.

Lithornithidae, an assemblage of volant Palaeogene fossil birds, provide our clearest insights into the early evolutionary history of Palaeognathae, the clade that today includes the flightless ratites and volant tinamous. The neotype specimen of Lithornis vulturinus, from the early Eocene (approximately 53 million years ago) of Europe, includes a partial neurocranium that has never been thoroughly investigated. Here, we describe these cranial remains including the nearly complete digital endocasts of the brain and bony labyrinth. The telencephalon of Lithornis is expanded and its optic lobes are ventrally shifted, as is typical for crown birds. The foramen magnum is positioned caudally, rather than flexed ventrally as in some crown birds, with the optic lobes, cerebellum, and foramen magnum shifted further ventrally. The overall brain shape is similar to that of tinamous, the only extant clade of flying palaeognaths, suggesting that several aspects of tinamou neuroanatomy may have been evolutionarily conserved since at least the early Cenozoic. The estimated ratio of the optic lobe's surface area relative to the total brain suggests a diurnal ecology. Lithornis may provide the clearest insights to date into the neuroanatomy of the ancestral crown bird, combining an ancestrally unflexed brain with a caudally oriented connection with the spinal cord, a moderately enlarged telencephalon, and ventrally shifted, enlarged optic lobes.

Evolución de la biodiversidad amazónica: una revisión

ABSTRACT Amazonia (defined herein as the Amazon basin) is home to the greatest concentration of biodiversity on Earth, providing unique genetic resources and ecological functions that contribute to ecosystem services globally. The lengthy and complex evolutionary history of this region has produced heterogeneous landscapes and riverscapes at multiple scales, altered the geographic and genetic connections among populations, and impacted rates of adaptation, speciation, and extinction. In turn, ecologically diverse Amazonian biotas promoted further diversification, species coexistence, and coevolution, with biodiversity accumulating over tens of millions of years. Important events in Amazonian history included: (i) late Cretaceous and early Paleogene origin of major rainforest plant and animal groups; (ii) Eocene-Oligocene global cooling with rainforests contracting to tropical latitudes separating Atlantic coastal and Amazonian rainforests; (iii) Miocene uplift of central and northern Andes that separated Pacific coastal and Amazonian rainforests, spurred formation of mega-wetlands in the western Amazon, and contributed to the origin of the modern transcontinental Amazon River; (iv) late Neogene formation of the Panamanian Isthmus that facilitated the Great American Biotic Interchange; (v) Pleistocene climate oscillations followed by late Pleistocene-Holocene human colonization and megafaunal extinctions; and (vi) modern era of widespread anthropogenic deforestation, defaunation, and ecological transformations of regional landscapes and global climates. Amazonian conservation requires decade-scale investments into biodiversity documentation and monitoring to leverage existing scientific capacity, and strategic habitat planning to allow continuity of evolutionary and ecological processes now and into the future.

In the Footsteps of Wolfgang Franke: Revisiting Chinese Temples in Bangkok

In the Footsteps of Wolfgang Franke: Revisiting Chinese Temples in Bangkok

Preperation of Sambhar Premix

Abstract: A sambhar premix is a convenient blend of dry spices and lentils essential for preparing the popular South Indian dish, sambhar. Comprising roasted and ground ingredients like lentils (toor dal, masoor dal), spices (coriander, cumin, fenugreek, mustard seeds), dried red chilies, and aromatics (turmeric, asafetida, curry leaves); this premix offers a quick solution to recreate the flavorsome and aromatic sambhar. When stored in an airtight container, this premix maintains its freshness, making it a time-saving and versatile addition to various culinary creations. masala development process would highlight the key steps and considerations in creating this traditional South Indian spice blend. It would cover aspects suchas ingredient selection, proportioning, grinding techniques, and the preservation methods employed. Additionally, the abstract might touch upon the cultural significance of masala and its role in enhancing the flavor profile of the iconic dish. This abstract delves into the historical evolution of masala, exploring its traditional ingredients and tracing the development of a premix. The document outlines the meticulous method of preparation for the premix, emphasizing key steps such as ingredient selection, proportioning, and grinding techniques. Additionally, it includes a comprehensive cost analysis of the production process. Proximate testing is employed to evaluate the nutritional composition of the masala, shedding light on itsdietary implications. This abstract aims to provide a holistic overview of the masala development process, combining historical context, preparation methodology, cost considerations, and nutritional insights. This detailed abstract explores the rich history, intricate ingredients, and methodical preparation of masala powder, with a focus on developing a premix. The historical analysis delves into the origins and evolution of the spice blend, highlighting the regional variations and cultural significance associated with its use in South Indian cuisine. The document provides a comprehensive overview of the ingredients, emphasizing the selection of authentic spices crucial to achieving the distinctive flavor profile. The method of preparation for the premix is detailed, encompassing precise measurements, grinding techniques, and the blending process to ensure consistency and optimal flavor infusion. A meticulous cost analysis is presented, covering raw materials, processing expenses,and packaging costs, offering insights into the economic feasibility of producing masala on a larger scale. Furthermore, proximate testing is employed to assess the nutritional composition, detailingthe macronutrient and micronutrient content, contributing to a comprehensive understanding of the spice blend's dietary implications. This abstract aims to serve as a comprehensive reference, encapsulating the historical, culinary, economic, and nutritional dimensions of masala powder and its premix variant.

The phage shock protein (PSP) envelope stress response: discovery of novel partners and evolutionary history.

Bacterial phage shock protein (PSP) systems stabilize the bacterial cell membrane and protect against envelope stress. These systems have been associated with virulence, but despite their critical roles, PSP components are not well characterized outside proteobacteria. Using comparative genomics and protein sequence-structure-function analyses, we systematically identified and analyzed PSP homologs, phyletic patterns, domain architectures, and gene neighborhoods. This approach underscored the evolutionary significance of the system, revealing that its core protein PspA (Snf7 in ESCRT outside bacteria) was present in the last universal common ancestor and that this ancestral functionality has since diversified into multiple novel, distinct PSP systems across life. Several novel partners of the PSP system were identified: (i) the Toastrack domain, likely facilitating assembly of sub-membrane stress-sensing and signaling complexes, (ii) the newly defined HTH-associated α-helical signaling domain-PadR-like transcriptional regulator pair system, and (iii) multiple independent associations with ATPase, CesT/Tir-like chaperone, and Band-7 domains in proteins thought to mediate sub-membrane dynamics. Our work also uncovered links between the PSP components and other domains, such as novel variants of SHOCT-like domains, suggesting roles in assembling membrane-associated complexes of proteins with disparate biochemical functions. Results are available at our interactive web app, https://jravilab.org/psp.IMPORTANCEPhage shock proteins (PSP) are virulence-associated, cell membrane stress-protective systems. They have mostly been characterized in Proteobacteria and Firmicutes. We now show that a minimal PSP system was present in the last universal common ancestor that evolved and diversified into newly identified functional contexts. Recognizing the conservation and evolution of PSP systems across bacterial phyla contributes to our understanding of stress response mechanisms in prokaryotes. Moreover, the newly discovered PSP modularity will likely prompt new studies of lineage-specific cell envelope structures, lifestyles, and adaptation mechanisms. Finally, our results validate the use of domain architecture and genetic context for discovery in comparative genomics.

Counter-gradient variation in gene expression between fish populations facilitates colonization of low-dissolved oxygen environments.

The role of phenotypic plasticity during colonization remains unclear due to the shifting importance of plasticity across timescales. In the early stages of colonization, plasticity can facilitate persistence in a novel environment; but over evolutionary time, processes such as genetic assimilation may reduce variation in plastic traits such that species with a longer evolutionary history in an environment can show lower levels of plasticity than recent invaders. Therefore, comparing species in the early stages of colonization to long-established species provides a powerful approach for uncovering the role of phenotypic plasticity during different stages of colonization. We compared gene expression between low-dissolved oxygen (DO) and high-DO populations of two cyprinid fish: Enteromius apleurogramma, a species that has undergone a recent range expansion, and E. neumayeri, a long-established native species in the same region. We sampled tissue either immediately after capture from the field or after a 2-week acclimation under high-DO conditions, allowing us to test for both evolved and plastic differences in low-DO vs high-DO populations of each species. We found that most genes showing candidate-evolved differences in gene expression did not overlap with those showing plastic differences in gene expression. However, in the genes that did overlap, there was counter-gradient variation such that plastic and evolved gene expression responses were in opposite directions in both species. Additionally, E. apleurogramma had higher levels of plasticity and evolved divergence in gene expression between field populations. We suggest that the higher level of plasticity and counter-gradient variation may have allowed rapid genetic adaptation in E. apleurogramma and facilitated colonization. This study shows how counter-gradient variation may impact the colonization of divergent oxygen environments.

The diverse liver viromes of Australian geckos and skinks are dominated by hepaciviruses and picornaviruses and reflect host taxonomy and habitat

ABSTRACT Lizards have diverse ecologies and evolutionary histories, and represent a promising group to explore how hosts shape virome structure and virus evolution. Yet little is known about the viromes of these animals. In Australia, squamates (lizards and snakes) comprise the most diverse order of vertebrates, and Australia hosts the highest diversity of lizards globally, with the greatest breadth of habitat use. We used meta-transcriptomic sequencing to determine the virome of nine co-distributed, tropical lizard species from three taxonomic families in Australia and analyzed these data to identify host traits associated with viral abundance and diversity. We show that lizards carry a large diversity of viruses, identifying more than 30 novel, highly divergent vertebrate-associated viruses. These viruses were from nine viral families, including several that contain well known pathogens, such as the Flaviviridae, Picornaviridae, Bornaviridae, Iridoviridae and Rhabdoviridae. Members of the Flaviviridae were particularly abundant across species sampled here, largely belonging to the genus Hepacivirus: 14 novel hepaciviruses were identified, broadening the known diversity of this group and better defining its evolution by uncovering new reptilian clades. The evolutionary histories of the viruses studied here frequently aligned with the biogeographic and phylogenetic histories of the hosts, indicating that exogenous viruses may help infer host evolutionary history if sampling is strategic and sampling density high enough. Notably, analysis of alpha and beta diversity revealed that virome composition and richness in the animals sampled here was shaped by host taxonomy, and habitat. In sum, we identified a diverse range of reptile viruses that broadly contributes to our understanding of virus-host ecology and evolution.

Haplotype-resolved genome assembly and implementation of VitExpress, an open interactive transcriptomic platform for grapevine

Haplotype-resolved genome assemblies were produced for Chasselas and Ugni Blanc, two heterozygous Vitis vinifera cultivars by combining high-fidelity long-read sequencing and high-throughput chromosome conformation capture (Hi-C). The telomere-to-telomere full coverage of the chromosomes allowed us to assemble separately the two haplo-genomes of both cultivars and revealed structural variations between the two haplotypes of a given cultivar. The deletions/insertions, inversions, translocations, and duplications provide insight into the evolutionary history and parental relationship among grape varieties. Integration of de novo single long-read sequencing of full-length transcript isoforms (Iso-Seq) yielded a highly improved genome annotation. Given its higher contiguity, and the robustness of the IsoSeq-based annotation, the Chasselas assembly meets the standard to become the annotated reference genome for V. vinifera. Building on these resources, we developed VitExpress, an open interactive transcriptomic platform, that provides a genome browser and integrated web tools for expression profiling, and a set of statistical tools (StatTools) for the identification of highly correlated genes. Implementation of the correlation finder tool for MybA1, a major regulator of the anthocyanin pathway, identified candidate genes associated with anthocyanin metabolism, whose expression patterns were experimentally validated as discriminating between black and white grapes. These resources and innovative tools for mining genome-related data are anticipated to foster advances in several areas of grapevine research.

Planetary nebulae of the Large Magellanic Cloud I. A multiwavelength analysis

Planetary nebulae (PNe) have three main components: a central star (CS), ionized gas, and dust in the nebula. Each contains critical chemical fingerprints of the PN's evolution, which serve as tracers of the evolution, nucleosynthesis, and dust production that occurred during the preceding asymptotic giant branch (AGB) phase. We aim to build a bridge to link the PN phase to the evolution of progenitors, to better understand the dust production and mass-loss mechanism during the final AGB phase. Here we present a comprehensive study of nine Large Magellanic Cloud spherical or elliptical PNe whose observations from the UV through the IR are available in the literature. We characterize nebulae and CSs, finding information necessary to reconstruct the evolutionary history of mass-loss and dust production, such as as the amount of gas that makes up the nebula and the dust that surrounds the CS. We compared the observed energy distribution of the selected PNe to that obtained from photoionization modeling, taking the presence of dust into account. The physical and chemical parameters of the CSs were then compared with predictions from the evolutionary tracks. We characterize the source, assigning a progenitor, early-AGB mass to each CS. We estimate the mass of the nebula and the dust-to-gas ratio. For five objects, we find evidence for the presence of a near-IR bump, which would indicate the presence of hot dust.

Computational modeling of interval distributions in tonal space reveals paradigmatic stylistic changes in Western music history

Diachronic stylistic changes in music are to a large extent affected by composers’ different choices, for example regarding the usage of tones, intervals, and harmonies. Analyzing the tonal content of pieces of music and observing them over time is thus informative about large-scale historical changes. In this study, we employ a computational model that formalizes music-theoretic conceptualizations of tonal space, and use it to infer the most likely interval distributions for pieces in a large corpus of music, represented as so-called ‘bags of tonal pitch classes’. Our results show that tonal interval relations become increasingly complex, that the interval of the perfect fifth dominates compositions for centuries, and that one can observe a stark increase in the usage of major and minor thirds during the 19th century, which coincides with the emergence of extended tonality. In complementing prior research on the historical evolution of tonality, our study thus demonstrates how example-based music theory can be informed by quantitative analyses of large corpora and computational models.

Comprehensive phylogenomic analyses revealed higher‐level phylogenetic relationships within the Cucujiformia

AbstractThe Cucujiformia, with remarkable morphological, ecological, and behavioral diversity, is the most evolutionarily successful group within Coleoptera. However, the phylogenetic relationships among superfamilies within Cucujiformia remain elusive. To address the issues, we conducted a transcriptome‐based macro‐evolutionary study of this lineage. We sequenced the genomes and transcriptomes of three species from the superfamily Curculionoidea (two from Curculionidae and one from Brentidae), and obtained a data set of more than 569 990 amino acid alignments from 143 species of Cucujiformia. With the most complete collection of whole genomes and transcriptomes so far, we compared the performance of different data matrices with universal‐single‐copy orthologs (USCO). The resultant trees based on different data sets were consistent for the majority of deep nodes. Two USCO amino acid matrices (i.e., USCO75 and USCO750‐abs80) provided well‐resolved topology. The analyses confirm that Cucujoidea sensu Robertson et al. 2015 is a nonmonophyletic group, consisting of Erotyloidea, Nitiduloidea, and Cucujoidea sensu Cai et al. 2022. Moreover, Erotyloidea is the early‐diverging group, followed by the clade Nitiduloidea. The preferred topologies supported a “basal” split of Coccinelloidea from the remaining superfamilies, and Cleroidea formed the second splitting group. The following phylogeny was supported at the superfamily level in Cucujiformia: (Coccinelloidea, (Cleroidea, ((Lymexyloidea, Tenebrionoidea), (Erotyloidea, (Nitiduloidea, (Cucujoidea, (Chrysomeloidea, Curculionoidea))))))). Our comprehensive analyses recovered well‐resolved higher‐level phylogenetic relationships within the Cucujiformia, providing a stable framework for comprehending its evolutionary history.

Limited herbivore migration during the Last Glacial Period of Kenya.

Eastern Africa is home to the largest terrestrial migrations on Earth. Though these migratory systems have been well studied for decades, little is known of their antiquity and evolutionary history. Serially sampled strontium stable isotopes (87Sr/86Sr) from tooth enamel can be used to track migration in mammals. Here we analyse 87Sr/86Sr for 79 bovid and equid individuals representing 18 species from four localities in Kenya to characterize prehistoric migratory systems during the Last Glacial Period (115-11.7 ka). Of the species analysed, 16 lack definitive evidence for migration, including blue wildebeest (Connochaetes taurinus), Thomson's gazelle (Eudorcas thomsonii) and plains zebra (Equus quagga), which are long-distance migrants today in the Greater Serengeti Ecosystem and historically in the Athi-Kapiti Plains. Only two species, the extinct wildebeests Rusingoryx atopocranion and Megalotragus sp., were migratory. These findings suggest a possible alternative narrative about ecosystem dynamics during the Last Glacial Period and shed light on the behaviour of both extant and extinct species at this time. In particular, these results indicate that migratory behaviour in extant species either emerged during the Holocene or was more spatiotemporally constrained in the past. Our results contribute to a growing body of evidence suggesting that the structure and function of geologically recent large mammal communities in eastern Africa differed considerably from those observed in the present day.

Deep history of cultural and linguistic evolution among Central African hunter-gatherers.

Human evolutionary history in Central Africa reflects a deep history of population connectivity. However, Central African hunter-gatherers (CAHGs) currently speak languages acquired from their neighbouring farmers. Hence it remains unclear which aspects of CAHG cultural diversity results from long-term evolution preceding agriculture and which reflect borrowing from farmers. On the basis of musical instruments, foraging tools, specialized vocabulary and genome-wide data from ten CAHG populations, we reveal evidence of large-scale cultural interconnectivity among CAHGs before and after the Bantu expansion. We also show that the distribution of hunter-gatherer musical instruments correlates with the oldest genomic segments in our sample predating farming. Music-related words are widely shared between western and eastern groups and likely precede the borrowing of Bantu languages. In contrast, subsistence tools are less frequently exchanged and may result from adaptation to local ecologies. We conclude that CAHG material culture and specialized lexicon reflect a long evolutionary history in Central Africa.

PhDs - Portugal has Doctors: A Visualization of Academia Achievements in Portugal from 1970 to 2022.

PhDs - Portugal has Doctors is an interactive installation presenting Portuguese doctoral theses from 1970 to 2022, tracking their historical evolution and distribution across universities and research sectors. This work resulted in an installation that served a dual purpose: to raise awareness and value the work of national doctorates and to reduce the communication gap on this topic, encouraging a public engagement with the subject, fostering discussions beyond the data and prompting reflection on how this lesser-known reality has impacted Portugal with its significantly growing presence. Drawing from recent research on aesthetics and its impact on data perception, we integrated these insights to make the visualization approach accessible to the general public, emphasizing a visually minimalist narrative. The story initially prompts viewers to reflect on the temporal evolution of the academic landscape over the last decades. The visualization then encourages viewers to actively engage with the data, facilitating a more in-depth exploration. The installation garnered positive feedback, provoking amazement and surprise, and revealed an unknown reality, even within the scientific community further justifying the need for this type of dissemination works.

Evolutionary and functional analyses of LRP5 in archaic and extant modern humans

BackgroundThe human lineage has undergone a postcranial skeleton gracilization (i.e. lower bone mass and strength relative to body size) compared to other primates and archaic populations such as the Neanderthals. This gracilization has been traditionally explained by differences in the mechanical load that our ancestors exercised. However, there is growing evidence that gracilization could also be genetically influenced.ResultsWe have analyzed the LRP5 gene, which is known to be associated with high bone mineral density conditions, from an evolutionary and functional point of view. Taking advantage of the published genomes of archaic Homo populations, our results suggest that this gene has a complex evolutionary history both between archaic and living humans and within living human populations. In particular, we identified the presence of different selective pressures in archaics and extant modern humans, as well as evidence of positive selection in the African and South East Asian populations from the 1000 Genomes Project. Furthermore, we observed a very limited evidence of archaic introgression in this gene (only at three haplotypes of East Asian ancestry out of the 1000 Genomes), compatible with a general erasing of the fingerprint of archaic introgression due to functional differences in archaics compared to extant modern humans. In agreement with this hypothesis, we observed private mutations in the archaic genomes that we experimentally validated as putatively increasing bone mineral density. In particular, four of five archaic missense mutations affecting the first β-propeller of LRP5 displayed enhanced Wnt pathway activation, of which two also displayed reduced negative regulation.ConclusionsIn summary, these data suggest a genetic component contributing to the understanding of skeletal differences between extant modern humans and archaic Homo populations.

Discovery of novel RNA viruses through analysis of fungi-associated next-generation sequencing data

BackgroundLike all other species, fungi are susceptible to infection by viruses. The diversity of fungal viruses has been rapidly expanding in recent years due to the availability of advanced sequencing technologies. However, compared to other virome studies, the research on fungi-associated viruses remains limited.ResultsIn this study, we downloaded and analyzed over 200 public datasets from approximately 40 different Bioprojects to explore potential fungal-associated viral dark matter. A total of 12 novel viral sequences were identified, all of which are RNA viruses, with lengths ranging from 1,769 to 9,516 nucleotides. The amino acid sequence identity of all these viruses with any known virus is below 70%. Through phylogenetic analysis, these RNA viruses were classified into different orders or families, such as Mitoviridae, Benyviridae, Botourmiaviridae, Deltaflexiviridae, Mymonaviridae, Bunyavirales, and Partitiviridae. It is possible that these sequences represent new taxa at the level of family, genus, or species. Furthermore, a co-evolution analysis indicated that the evolutionary history of these viruses within their groups is largely driven by cross-species transmission events.ConclusionsThese findings are of significant importance for understanding the diversity, evolution, and relationships between genome structure and function of fungal viruses. However, further investigation is needed to study their interactions.

No immediate attentional bias towards or choice bias for male secondary sexual characteristics in Bornean orang-utans (Pongo pygmaeus).

Primate faces provide information about a range of variant and invariant traits, including some that are relevant for mate choice. For example, faces of males may convey information about their health or genetic quality through symmetry or facial masculinity. Because perceiving and processing such information may have bearing on the reproductive success of an individual, cognitive systems are expected to be sensitive to facial cues of mate quality. However, few studies have investigated this topic in non-human primate species. Orang-utans are an interesting species to test mate-relevant cognitive biases, because they are characterised by male bimaturism: some adult males are fully developed and bear conspicuous flanges on the side of their face, while other males look relatively similar to females. Here, we describe two non-invasive computerised experiments with Bornean orang-utans (Pongo pygmaeus), testing (i) immediate attention towards large flanges and symmetrical faces using a dot-probe task (N = 3 individuals; 2F) and (ii) choice bias for pictures of flanged males over unflanged males using a preference test (N = 6 individuals; 4F). In contrast with our expectations, we found no immediate attentional bias towards either large flanges or symmetrical faces. In addition, individuals did not show a choice bias for stimuli of flanged males. We did find exploratory evidence for a colour bias and energy efficiency trade-offs in the preference task. We discuss our null results and exploratory results in the context of the evolutionary history of Bornean orang-utans, and provide suggestions for a more biocentric approach to the study oforang-utan cognition.

Party Politics in West Bengal: Historical and Contemporary Dynamics

Party politics in West Bengal is a complex and ever-evolving phenomenon deeply rooted in the state's socio-cultural history. This overview explores the dynamic landscape of party politics in West Bengal, tracing its historical evolution and examining the key players, ideological underpinnings, electoral strategies, and socio-economic factors that have influenced voter preferences over the years. From the pre-independence era's freedom struggle to the contemporary political dynamics dominated by the All-India Trinamool Congress (AITC) and Bharatiya Janata Party (BJP), West Bengal's political journey reflects its vibrant cultural mosaic and socio-political complexities. This paper also discusses the current scenario in West Bengal, highlighting the role of various political parties in recent local and assembly elections. The methodology involves a comprehensive review of academic papers and journals on various aspects of West Bengal's politics, governance, and societal dynamics. While existing literature touches on governance-related aspects like healthcare policies, decentralisation, and power sector reforms, there is a research gap in integrating these elements to provide a holistic assessment of West Bengal's governance model. The paper identifies this research gap and calls for a more comprehensive study that explores the interplay of political decisions, decentralisation efforts, and policy reforms in shaping the state's development and governance outcomes.

Opposite Ends: Why the United States and Singapore have Drastically Different Models of Free Speech

This article delves into why the United States and Singapore, despite their shared colonial history, democratic institutions, wealth, and global influence, have drastically different free speech models. This paper will look at three points of comparison: historical context, political theory, and evolution of judicial interpretation. By comparing the current events and the prevalent political theories at the time of drafting the Singaporean and American constitutions, this paper seeks to understand why the nations ratified contrasting free speech clauses.  However, the Constitution is only as meaningful as the courts interpret it, so this paper also explores how the respective Supreme Courts of Singapore and America have evolved their interpretation of the Constitution to shape their contrasting free speech models. While this paper will not argue which model of free speech is more effective, it will outline the underlying reasons for Singapore and America's drastically different free speech models.