Simon Y. W. Ho's research while affiliated with The University of Sydney and other places

Publications (400)

Preprint
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Determining the link between genomic and phenotypic evolution is a fundamental goal in evolutionary biology. Insights into this link can be gained by using a phylogenetic approach to test for correlations between rates of molecular and morphological evolution. However, there has been persistent uncertainty about the relationship between these rates...
Article
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Marine animals such as the southern elephant seal (Mirounga leonina) rely on a productive marine environment and are vulnerable to oceanic changes that can affect their reproduction and survival rates. Davis Base, Antarctica, acts as a moulting site for southern elephant seals that forage in Prydz Bay, but the mitochondrial haplotype diversity and...
Article
Characterizing the detailed spatial and temporal dynamics of plant pathogens can provide valuable information for crop protection strategies. However, the epidemiological characteristics and evolutionary trajectories of pathogens can differ markedly from one country to another. The most widespread and important virus of brassica vegetables, turnip...
Article
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The present-day ubiquity of angiosperm-insect pollination has led to the hypothesis that these two groups coevolved early in their evolutionary history. However, recent fossil discoveries and fossil-calibrated molecular dating analyses challenge the notion that early diversifications of angiosperms and insects were inextricably linked. In this arti...
Preprint
Full-text available
Marine animals such as the southern elephant seal (Mirounga leonina) rely on a productive marine environment and are vulnerable to oceanic changes that can affect their reproduction and survival rates. Davis Base, Antarctica, acts as a moulting site for southern elephant seals that forage in Prydz Bay, but the genetic diversity and natal source pop...
Preprint
Full-text available
The present-day ubiquity of angiosperm-insect pollination has led to the hypothesis that these two groups coevolved early in their evolutionary history. However, recent fossil discoveries and fossil-calibrated molecular dating analyses challenge the notion that early diversifications of angiosperms and insects were inextricably linked. In this arti...
Preprint
Full-text available
Evolutionary timescales can be estimated using a combination of genetic data and fossil evidence based on the molecular clock. Bayesian phylogenetic methods such as tip dating and total-evidence dating provide a powerful framework for inferring evolutionary timescales, but the most widely used priors for tree topologies and node times often assume...
Article
The historical signal in nucleotide sequences becomes eroded over time by substitutions occurring repeatedly at the same sites. This phenomenon, known as substitution saturation, is recognized as one of the primary obstacles to deep-time phylogenetic inference using genome-scale data sets. We present a new test of substitution saturation and demons...
Preprint
Full-text available
The historical signal in nucleotide sequences becomes eroded over time by substitutions occurring repeatedly at the same sites. This phenomenon, known as substitution saturation, is recognized as one of the primary obstacles to deep-time phylogenetic inference using genome-scale data sets. We present a new test of substitution saturation and demons...
Article
Full-text available
Multiple lines of evidence show that modern humans interbred with archaic Denisovans. Here, we report an account of shared demographic history between Australasians and Denisovans distinctively in Island Southeast Asia. Our analyses are based on ∼2.3 million genotypes from 118 ethnic groups of the Philippines, including 25 diverse self-identified N...
Article
Full-text available
Phylogenetic analyses of genomic data provide a powerful means of reconstructing the evolutionary relationships among organisms, yet such analyses are often hindered by conflicting phylogenetic signals among loci. Identifying the signals that are the most influential to species-tree estimation can help to inform the choice of data for phylogenomic...
Article
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As the global biodiversity crisis deepens, with increasing habitat fragmentation and a changing climate, innovative options for conserving species are being explored. One such conservation action is genetic rescue: introduction of new alleles to promote population fitness. However, for critically endangered species where only one viable population...
Article
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Australian freshwater fishes are a relatively species-poor assemblage, mostly comprising groups derived from older repeated freshwater invasions by marine ancestors, plus a small number of Gondwanan lineages. These taxa are both highly endemic and highly threatened, but a comprehensive phylogeny for Australian freshwater fishes is lacking. This has...
Article
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Island Southeast Asia has recently produced several surprises regarding human history, but the region’s complex demography remains poorly understood. Here, we report ∼2.3 million genotypes from 1,028 individuals representing 115 indigenous Philippine populations and genome-sequence data from two ∼8,000-y-old individuals from Liangdao in the Taiwan...
Article
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Plant pathogens have agricultural impacts on a global scale and resolving the timing and route of their spread can aid crop protection and inform control strategies. However, the evolutionary and phylogeographic history of plant pathogens in Eurasia remains largely unknown because of the difficulties in sampling across such a large landmass. Here,...
Article
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The fairy wrasses (genus Cirrhilabrus) are among the most successful of the extant wrasse lineages (Teleostei: Labridae), with their 61 species accounting for nearly 10% of the family. Although species complexes within the genus have been diagnosed on the basis of coloration patterns and synapomorphies, attempts to resolve evolutionary relationship...
Article
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The segmented trapdoor spiders (Liphistiidae) are the sole surviving family of the suborder Mesothelae, which forms the sister lineage to all other living spiders. Liphistiids have retained a number of plesiomorphic traits and their present-day distribution is limited to East and Southeast Asia. Studying this group has the potential to shed light o...
Article
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Homotherium was a genus of large-bodied scimitar-toothed cats, morphologically distinct from any extant felid species, that went extinct at the end of the Pleistocene [1, 2, 3, 4]. They possessed large, saber-form serrated canine teeth, powerful forelimbs, a sloping back, and an enlarged optic bulb, all of which were key characteristics for predati...
Article
The ability to sequence genomes from ancient biological material has provided a rich source of information for evolutionary biology and engaged considerable public interest. Although most studies of ancient genomes have focused on vertebrates, particularly archaic humans, newer technologies allow the capture of microbial pathogens and microbiomes f...
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Pleistocene glacial-interglacial cycles are correlated with dramatic temperature oscillations. Examining how species responded to these natural fluctuations can provide valuable insights into the impacts of present-day anthropogenic climate change. Here we present a phylogeographic study of the extinct American mastodon (Mammut americanum), based o...
Article
Full-text available
Potato virus Y (PVY) is a destructive plant pathogen that causes considerable losses to global potato and tobacco production. Although the molecular structure of PVY is well characterized, the evolutionary and global transmission dynamics of this virus remain poorly understood. We investigated the phylodynamics of the virus by analysing 253 nucleot...
Article
The evolutionary processes that drive variation in genome size across the tree of life remain unresolved. Effective population size (Ne) is thought to play an important role in shaping genome size [1, 2, 3]—a key example being the reduced genomes of insect endosymbionts, which undergo population bottlenecks during transmission [4]. However, the exi...
Article
Phylogenetic methods can use the sampling times of molecular sequence data to calibrate the molecular clock, enabling the estimation of evolutionary rates and timescales for rapidly evolving pathogens and data sets containing ancient DNA samples. A key aspect of such calibrations is whether a sufficient amount of molecular evolution has occurred ov...
Article
Determining species boundaries forms an important foundation for biological research. However, the results of molecular species delimitation can vary with the data sets and methods that are used. Here we use a two-step approach to delimit species in the genus Heptathela, a group of primitively segmented trapdoor spiders that are endemic to Japanese...
Article
Advances in sequencing technologies have revolutionized wildlife conservation genetics. Analysis of genomic data sets can provide high-resolution estimates of genetic structure, genetic diversity, gene flow, and evolutionary history. These data can be used to characterize conservation units and to effectively manage the genetic health of species in...
Preprint
Full-text available
The phylogenetic information contained in sequence data is partly determined by the overall rate of nucleotide substitution in the genomic region in question. However, phylogenetic signal is affected by various other factors, such as heterogeneity in substitution rates across lineages. These factors might be able to predict the phylogenetic accurac...
Article
Full-text available
Bacterial endosymbionts evolve under strong host-driven selection. Factors influencing host evolution might affect symbionts in similar ways, potentially leading to correlations between the molecular evolutionary rates of hosts and symbionts. Although there is evidence of rate correlations between mitochondrial and nuclear genes, similar investigat...
Article
Full-text available
Water lilies belong to the angiosperm order Nymphaeales. Amborellales, Nymphaeales and Austrobaileyales together form the so-called ANA-grade of angiosperms, which are extant representatives of lineages that diverged the earliest from the lineage leading to the extant mesangiosperms1–3. Here we report the 409-megabase genome sequence of the blue-pe...
Book
This book presents coverage of the principles and practice of molecular clocks, which have provided fascinating and unprecedented insights into the evolutionary timescale of life on earth. It begins by following the early development of the molecular evolutionary clock in the 1960s, and leads to the complex statistical approaches that are now used...
Article
Full-text available
Establishing an accurate evolutionary timescale for green plants (Viridiplantae) is essential to understanding their interaction and coevolution with the Earth’s climate and the many organisms that rely on green plants. Despite being the focus of numerous studies, the timing of the origin of green plants and the divergence of major clades within th...
Chapter
Molecular clocks can be used to reconstruct evolutionary timescales based on analyses of genetic data, but these clocks need to be calibrated in order to give estimates in absolute time. Calibration is most often carried out using fossil evidence of the timing of evolutionary events, corresponding to internal nodes in phylogenetic trees. Early mole...
Chapter
The molecular evolutionary clock was proposed in the 1960s and has undergone considerable evolution over the past six decades. After arising from early studies of the amino acid sequences of proteins, the molecular clock became a point of contention between competing theories of molecular evolution. In this chapter, I describe the origins of the mo...
Article
Evolution leaves heterogeneous patterns of nucleotide variation across the genome, with different loci subject to varying degrees of mutation, selection, and drift. In phylogenetics, the potential impacts of partitioning sequence data for the assignment of substitution models are well appreciated. In contrast, the treatment of branch lengths has re...
Article
Full-text available
A common goal of population genomics and molecular ecology is to reconstruct the demographic history of a species of interest. A pair of powerful tools based on the sequentially Markovian coalescent have been developed to infer past population sizes using genome sequences. These methods are most useful when sequences are available for only a limite...
Article
Insects are a highly diverse group of organisms and constitute more than half of all known animal species. They have evolved an extraordinary range of traits, from flight and complete metamorphosis to complex polyphenisms and advanced eusociality. Although the rich insect fossil record has helped to chart the appearance of many phenotypic innovatio...
Article
Bayesian phylogenetic methods derived from evolutionary biology can be used to reconstruct the history of human languages using databases of cognate words. These analyses have produced exciting results regarding the origins and dispersal of linguistic and cultural groups through prehistory. Bayesian lexical dating requires the specification of prio...
Article
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The geographic distributions of marine fishes have been shaped by ancient vicariance and ongoing dispersal events. Some species exhibit anti‐equatorial distributions, inhabiting temperate regions on both sides of the tropics while being absent from equatorial latitudes. The perciform fish Microcanthus strigatus (the stripey) exhibits such a distrib...
Article
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Cryptocercus Scudder is a genus of wingless cockroaches, which spend their lives feeding within rotting wood in old‐growth montane forests. Their dispersal capability is likely to be limited because they depend on the succession of temperate forests, but their distribution exhibits intercontinental disjunctions. Although the natural history and con...
Article
Full-text available
Niche partitioning can lead to differences in the range dynamics of plant species through its impacts on habitat availability, dispersal, or selection for traits that affect colonization and persistence. We investigated whether niche partitioning into upland and riparian habitats differentiates the range dynamics of two closely related and sympatri...
Article
Full-text available
Bayesian molecular dating is widely used to study evolutionary timescales. This procedure usually involves phylogenetic analysis of nucleotide sequence data, with fossil based calibrations applied as age constraints on internal nodes of the tree. An alternative approach is tip-dating, which explicitly includes fossil data in the analysis. This can...
Article
Full-text available
Disentangling phylogenetic relationships proves challenging for groups that have evolved recently, especially if there is ongoing reticulation. Although they are in most cases immediately isolated from diploid relatives, sets of sibling allopolyploids often hybridize with each other, thereby increasing the complexity of an already challenging situa...
Article
Sexual selection is a powerful agent of evolution, driving microevolutionary changes in the genome and macroevolutionary rates of lineage diversification. The mechanisms by which sexual selection might influence macroevolution remain poorly understood. For example, sexual selection might drive positive selection for key adaptations that facilitate...
Data
TABLE S1 The control file parameter values defined for the branch models in EasyCodeML TABLE S2 The control file parameter values defined for the branch-site models in EasyCodeML TABLE S3 The control file parameter values defined for the site models in EasyCodeML TABLE S4 The control file parameter values defined for the clade models in EasyCode...
Article
Full-text available
The genomic signatures of positive selection and evolutionary constraints can be detected by analyses of nucleotide sequences. One of the most widely used programs for this purpose is CodeML, part of the PAML package. Although a number of bioinformatics tools have been developed to facilitate the use of CodeML, these have various limitations. Here,...
Data
FIGURE 1 Screenshot of the main interface of EasyCodeML under the (a) preset and (b) custom running modes. In the preset mode, all key parameters of the nested models are built-in and there is a pipeline from data input to the output of results. In the custom mode, the parameters of any codon-based model can be modified to meet the requirements of...
Article
The timing and tempo of the processes involved in community assembly are of substantial concern to community ecologists and conservation managers. The fossil record is a valuable source of data for studying past changes in community composition, but it is not always detailed enough to allow the process of community assembly to be resolved at region...
Data
FIGURE 3 Two utilities available in EasyCodeML: (a) the LRT calculator, and Seqformat convertor in (b) a user-friendly GUI or (c) command line. Seqformat convertor can convert between diverse types of sequence data formats.
Data
FIGURE2 Labelling branches in a tree for the branch-related models can be done in a simple and intuitive way for the (a) clade models and (b) branch and branch-site models.
Preprint
Full-text available
Bacterial endosymbionts evolve under strong host-driven selection. Factors influencing host evolution might affect symbionts in similar ways, potentially leading to correlations between the molecular evolutionary rates of hosts and symbionts. Although there is evidence of rate correlations between mitochondrial and nuclear genes, similar investigat...
Article
Full-text available
The mantis shrimp superfamily Squilloidea, with over 185 described species, is the largest superfamily in the crustacean order Stomatopoda. To date, phylogenetic relationships within this superfamily have been comprehensively analysed using morphological data, with six major generic groupings being recovered. Here, we infer the phylogeny of Squillo...
Article
Full-text available
Background: Phylogenetic analysis of DNA from modern and ancient samples allows the reconstruction of important demographic and evolutionary processes. A critical component of these analyses is the estimation of evolutionary rates, which can be calibrated using information about the ages of the samples. However, the reliability of these rate estim...
Preprint
Full-text available
Evolution leaves heterogeneous patterns of nucleotide variation across the genome, with different loci subject to varying degrees of mutation, selection, and drift. Appropriately modelling this heterogeneity is important for reliable phylogenetic inference. One modelling approach in statistical phylogenetics is to apply independent models of molecu...
Preprint
Full-text available
Bayesian molecular dating is widely used to study evolutionary timescales. This procedure usually involves phylogenetic analysis of nucleotide sequence data, with fossil-based calibrations applied as age constraints on internal nodes of the tree. An alternative approach is Bayesian total-evidence dating, which involves the joint analysis of molecul...
Article
Potato virus S (PVS) is a major plant pathogen that causes considerable losses in global potato production. Knowledge of the evolutionary history and spatio-temporal dynamics of PVS is vital for developing sustainable management schemes. In this study, we investigated the phylodynamics of the virus by analysing 103 nucleotide sequences of the coat...
Article
A fundamental challenge in resolving evolutionary relationships across the Tree of Life is to account for heterogeneity in the evolutionary signal across loci. Studies of marsupial mammals have demonstrated that this heterogeneity can be substantial, leaving considerable uncertainty in the evolutionary timescale and relationships within the group....
Article
The molecular clock provides a valuable means of estimating evolutionary timescales from genetic and biochemical data. Proposed in the early 1960s, it was first applied to amino acid sequences and immunological measures of genetic distances between species. The molecular clock has undergone considerable development over the years, and it retains pr...
Data
Table S5. Detailed Metadata and Genome Statistics for 220 Bacterial Strains in the Para C Lineage plus 2 Birkenhead Strains, Related to Figure 2