William John Baker

Royal Botanic Gardens, Kew · Kew Science

Biological collections are at the front line of biodiversity research, informing taxonomy, evolution, conservation and sustainable livelihoods. In April 2014, we organised a meeting at the Linnean Society (UK) discussing the impact of next-generation sequencing (NGS) methods on collections-based research. Here, we explore the main themes of this me...

The systematic biology of the palm family (Arecaceae) is probably better known than that of any other tropical plant family of comparable size. As a result, the palms are now regarded as a model group for tropical rain forest research. Ten years ago, the first phylogenetic classification of palms was established as a foundation for the second editi...

Summary' I. 'Introduction' II. 'A brief history of hypotheses' III. 'Age of TRF biome and lineages' IV. 'Frequency of immigration from other biomes' V. 'Speciation and extinction' VI. 'Ecological limits' VII. 'Key methodological challenges' VIII. 'Perspectives' IX. 'Conclusions' 'Acknowledgements' References Tropical rainforest (TRF) is the most sp...

A diverse range of high-throughput sequencing data, such as target capture, RNA-Seq, genome skimming, and high-depth whole genome sequencing, are amenable to phylogenomic analyses but the integration of such mixed data types into a single phylogenomic dataset requires a number of bioinformatic tools and significant computational resources. Here, we...

Model species continue to underpin groundbreaking plant science research. At the same time, the phylogenetic resolution of the land plant Tree of Life continues to improve. The intersection of these two research paths creates a unique opportunity to further extend the usefulness of model species across larger taxonomic groups. Here we promote the u...

Model species continue to underpin groundbreaking plant science research. At the same time, the phylogenetic resolution of the land plant Tree of Life continues to improve. The intersection of these two research paths creates a unique opportunity to further extend the usefulness of model species across larger taxonomic groups. Here we promote the u...

Poales are one of the most species-rich, ecologically and economically important orders of plants and often characterise open habitats, enabled by unique suites of traits. We test the hypotheses that Poales species are assembled into distinct phyloregions, with centres of high phylogenetic diversity and endemism clustered in tropical regions, and t...

A genus and species of palm from the Truong Son Range in Vietnam, Truongsonia lecongkietii, is described as new to science. Phylogenomic analysis strongly supports the placement of the new taxon in subfamily Arecoideae as sister to the African endemic tribe Podococceae, which comprises a single genus Podococcus. A new tribe Truongsonieae is also de...

Orchids constitute one of the most spectacular radiations of flowering plants. However, their geographical origin, historical spread across the globe, and hotspots of speciation remain uncertain due to the lack of a broad phylogenomic framework. ⍰ We present a new Orchidaceae phylogeny based on high-throughput and Sanger sequencing datasets, coveri...

The mustard family (Brassicaceae) is a scientifically and economically important family, containing the model plant Arabidopsis thaliana and numerous crop species that feed billions worldwide. Despite its relevance, most phylogenetic trees of the family are incompletely sampled and often contain poorly supported branches. Here, we present the most...

Background and aims: Understanding diaspore morphology and how much a species invests on dispersal appendages is key for improving our knowledge of dispersal in fragmented habitats. We investigate diaspore morphological traits in high-Andean Compositae, their main abiotic and biotic drivers and test whether they play a role in species distribution...

Regions harbouring high unique phylogenetic diversity (PD) are priority targets for conservation. Here, we analyse the global distribution of plant PD, which remains poorly understood despite plants being the foundation of most terrestrial habitats and key to human livelihoods. Capitalising on a recently completed, comprehensive global checklist of...

The production of flowers and fruit below ground (geoflory and geocarpy, respectively) is a paradoxical reproductive strategy that seemingly hinders pollination and dispersal. Though rare, these phenomena occur in 33 angiosperm families. Plants that flower and fruit entirely below ground are exceptionally unusual. Pinanga subterranea (Arecaceae), a...

A new acaulescent species of Pinanga (Arecoideae: Areceae: Arecinae) is described and illustrated here. This remarkable new species is the first palm described as flowering and fruiting underground, highlighting Borneo as a hotspot for palm diversity.

Background Over the past decade, phylogenomics has greatly advanced our knowledge of angiosperm evolution. However, phylogenomic studies of large angiosperm families with complete species or genus-level sampling are still lacking. The palms, Arecaceae, are a large family with ca. 181 genera and 2600 species and are important components of tropical...

Sapindales is an angiosperm order of high economic and ecological value comprising nine families, c. 479 genera, and c. 6570 species. However, family and subfamily relationships in Sapindales remain unclear, making reconstruction of the order’s spatio-temporal and morphological evolution difficult. In this study, we used Angiosperms353 target captu...

Premise: Recent phylogenetic studies of the Araceae have confirmed the position of the duckweeds nested within the aroids, and the monophyly of a clade containing all the unisexual flowered aroids plus the bisexual-flowered Calla palustris. The main objective of this work was to better resolve the deep phylogenetic relationships among the main lin...

The angiosperm family Primulaceae is morphologically diverse and distributed nearly worldwide. However, phylogenetic uncertainty has obstructed the identification of major morphological and biogeographic transitions within the clade. We used target capture sequencing with the Angiosperms353 probes, taxon-sampling encompassing nearly all genera of t...

1. Seed dispersal is a key process in the generation and maintenance of genetic diversity and genetic differentiation of plant populations in tropical ecosystems. During the Last Quaternary, most seed-dispersing megafauna was lost globally, but whether this has caused dispersal limitation, loss of genetic diversity, and increased genetic differenti...

Madagascar's biota is hyperdiverse and includes exceptional levels of endemicity. We review the current state of knowledge on Madagascar's past and current terrestrial and freshwater biodiversity by compiling and presenting comprehensive data on species diversity, endemism, and rates of species description and human uses, in addition to presenting...

Madagascar's unique biota is heavily affected by human activity and is under intense threat. Here, we review the current state of knowledge on the conservation status of Madagascar's terrestrial and freshwater biodiversity by presenting data and analyses on documented and predicted species-level conservation statuses, the most prevalent and relevan...

Protecting nature’s contributions to people requires accelerating extinction risk assessment and better integrating evolutionary, functional and used diversity with conservation planning. Here, we report machine learning extinction risk predictions for 1,381 palm species (Arecaceae), a plant family of high socio-economic and ecological importance....

The mustard family (Brassicaceae) is a scientifically and economically important family, containing the model plant Arabidopsis thaliana and numerous crop species that feed billions worldwide. Despite its relevance, most published family phylogenies are incompletely sampled, generally contain massive polytomies, and/or show incongruent topologies b...

With 178 species, palm subtribe Dypsidinae is one of the largest plant radiations on Madagascar. A well‐resolved species‐level phylogeny is required not only to unpick the drivers of this spectacular radiation, but also to define natural and useful generic limits in this taxonomically difficult group. The only recent taxonomic revision of Dypsidina...

As part of the Palms of New Guinea project we discovered a species of Licuala new to science with large white flowers, which is described here for the first time.

Species richness varies immensely around the world. Variation in the rate of diversification (speciation minus extinction) is often hypothesized to explain this pattern, while alternative explanations invoke time or ecological carrying capacities as drivers. Focusing on seed plants, the world’s most important engineers of terrestrial ecosystems, we...

Convolvulaceae is a family of c. 2,000 species, distributed across 60 currently recognized genera. It includes species of high economic importance, such as the crop sweet potato (Ipomoea batatas L.), the ornamental morning glories (Ipomoea L.), bindweeds (Convolvulus L.), and dodders, the parasitic vines (Cuscuta L.). Earlier phylogenetic studies,...

Genome size varies 2400‐fold across plants, influencing their evolution through changes in cell size and cell division rates which impact plants' environmental stress tolerance. Repetitive element expansion explains much genome size diversity, and the processes structuring repeat ‘communities’ are analogous to those structuring ecological communiti...

We examined the impact of successive alignment quality‐control steps on downstream phylogenomic analyses. We applied a recently published phylogenomics pipeline that was developed for the Angiosperms353 target‐sequence‐capture probe set to the flowering plant order Celastrales. Our final dataset consists of 158 species, including at least one exemp...

A global international initiative, such as the Earth BioGenome Project (EBP), requires both agreement and coordination on standards to ensure that the collective effort generates rapid progress toward its goals. To this end, the EBP initiated five technical standards committees comprising volunteer members from the global genomics scientific commun...

Reference: Lim, J.Y., Huang, H., Farnsworth, A., Lunt, D.J., Baker, W.J., Morley, R.J., Kissling, W.D. & Hoorn, C. (2022) The Cenozoic history of palms: Global diversification, biogeography, and the decline of megathermal forests. Contact: Jun Ying Lim (junyinglim@gmail.com), Huasheng Huang (buxushuang@gmail.com)

Aim Megathermal rain forests and mangroves are much smaller in extent today than in the early Cenozoic, primarily owing to global cooling and drying trends since the Eocene–Oligocene transition (c. 34 Ma). The general reduction of these biomes is hypothesized to shape the diversity and biogeographical history of tropical plant clades. However, thi...

Genome size varies 2,400-fold across plants, influencing their evolution through changes in cell size and cell division rates which impact plants’ environmental stress tolerance. Repetitive element expansion explains much genome size diversity, and the processes structuring repeat ‘communities’ are analogous to those structuring ecological communit...

The palm tribe Lepidocaryeae (Arecaceae) comprises seven genera and 51 currently accepted species that are distributed in lowland tropical forests and savannas across Africa and the Americas. Subtribal relationships within Lepidocaryeae have been a persistent challenge,limiting our understanding of its systematics, morphology, and biogeography. Sev...

Extinction has increased as human activities impact ecosystems, yet relatively few species have conservation assessments. Novel approaches are needed to highlight threatened species that are currently data-deficient. Many Madagascan plant species have extremely narrow ranges, but this may not have always been the case—it is unclear how the island's...

Societal Impact Statement Digitized molecular data are vital to numerous aspects of scientific research and genetic resource use. The Convention on Biological Diversity currently refers to this as “Digital Sequence Information” (DSI), a term not widely adopted by science and lacking a clear definition. There are concerns over the access to genetic...

Premise To further advance the understanding of the species-rich, economically and ecologically important angiosperm order Myrtales in the rosid clade, comprising nine families, approximately 400 genera and almost 14,000 species occurring on all continents (except Antarctica), we tested the Angiosperms353 probe kit. Methods We combined high-throug...

In this special issue of the American Journal of Botany, together with a companion issue of Applications in Plant Sciences, we gather a set of papers that focus on a new, common phylogenomic toolkit, the Angiosperms353 probe set, and illustrate its potential for evolutionary synthesis by promoting open collaboration across our community.

Premise: The carrot family (Apiaceae) comprises 466 genera, which include many well-known crops (e.g., aniseed, caraway, carrots, celery, coriander, cumin, dill, fennel, parsley, and parsnips). Higher-level phylogenetic relationships among subfamilies, tribes, and other major clades of Apiaceae are not fully resolved. This study aims to address th...

Premise: Resolving relationships within order Commelinales has posed quite a challenge, as reflected in its unstable infra-familial classification. Thus, we investigated (1) relationships across families and genera of Commelinales; (2) phylogenetic placement of never-before sequenced genera; (3) how well off-target plastid data integrate with othe...

Premise: Cunoniaceae are a family of shrubs and trees with 27 genera and ca. 335 species, mostly confined to tropical and wet temperate zones of the southern hemisphere. There are several known issues regarding generic limits, and the family also displays a number of intriguing long-range disjunctions. Methods: We performed a phylogenomic study...

Aim Since Wallace's and Engler's 19th-century biogeographical schemes, biogeographers have sought to classify the world into biogeographical regions according to patterns in biotic distribution. Yet, while most of the world's plant biodiversity can be found in the tropics, basic phytogeographical relationships and boundaries within this zone remain...

PREMISE: Comprising five families that vastly differ in species richness-ranging from Gelsemiaceae with 13 species to the Rubiaceae with 13,775 species-members of the Gentianales are often among the most species-rich and abundant plants in tropical forests. Despite considerable phylogenetic work within particular families and genera, several altern...

Premise: The inference of evolutionary relationships in the species-rich family Orchidaceae has hitherto relied heavily on plastid DNA sequences and limited taxon sampling. Previous studies have provided a robust plastid phylogenetic framework, which was used to classify orchids and investigate the drivers of orchid diversification. However, the e...

PREMISE: Researchers adopting target-enrichment approaches often struggle with the decision of whether to use universal or lineage-specific probe sets. To circumvent this quandary, we investigate the efficacy of a simultaneous enrichment by combining universal probes and lineage-specific probes in a single hybridization reaction, to benefit from th...

The date palm (Phoenix dactylifera L.) is an iconic crop of hot and arid regions of North Africa, the Middle East and up to northwestern India. It is a member of the genus Phoenix that constitutes a monophyletic group within the Coryphoideae subfamily, in the palm family. The genus Phoenix is composed of around 14 species whose native distribution...

Premise: The economically important, cosmopolitan soapberry family (Sapindaceae) comprises ca. 1900 species in 144 genera. Since the seminal work of Radlkofer, several authors have attempted to overcome challenges presented by the family's complex infra-familial classification. With the advent of molecular systematics, revisions of the various pro...

We present a densely sampled phylogenomic study of the mulberry tribe (Moreae, Moraceae), an economically important clade with a global distribution, revealing multiple losses of inflexed stamens, a character traditionally used to circumscribe Moreae. Inflexed stamens facilitate ballistic pollen release and are associated with wind pollination, and...

Premise: Custom probe design for target enrichment in phylogenetics is tedious and often hinders broader phylogenetic synthesis. The universal angiosperm probe set Angiosperms353 may be the solution. Here, we test the relative performance of Angiosperms353 on the Rosaceae subtribe Malinae in comparison with custom probes that we specifically desig...

The date palm, Phoenix dactylifera, has been a cornerstone of Middle Eastern and North African agriculture for millennia. It was first domesticated in the Persian Gulf, and its evolution appears to have been influenced by gene flow from two wild relatives, P. theophrasti, currently restricted to Crete and Turkey, and P. sylvestris, widespread from...

Premise: Both universal and family-specific targeted sequencing probe kits are becoming widely used for reconstruction of phylogenetic relationships in angiosperms. Within the pantropical Ochnaceae, we show that with careful data filtering, universal kits are equally as capable in resolving intergeneric relationships as custom probe kits. Furtherm...

PREMISE: Phylogenetic studies in the Compositae are challenging due to the sheer size of the family and the challenges they pose for molecular tools, ranging from the genomic impact of polyploid events to their very conserved plastid genomes. The search for better molecular tools for phylogenetic studies led to the development of the family-specifi...

Premise: Universal target enrichment kits maximize utility across wide evolutionary breadth while minimizing the number of baits required to create a cost-efficient kit. The Angiosperms353 kit has been successfully used to capture loci throughout the angiosperms, but the default target reference file includes sequence information from only 6-18 ta...

The tree of life is the fundamental biological roadmap for navigating the evolution and properties of life on Earth, and yet remains largely unknown. Even angiosperms (flowering plants) are fraught with data gaps, despite their critical role in sustaining terrestrial life. Today, high-throughput sequencing promises to significantly deepen our under...

Cyperaceae (sedges) are the third largest monocot family and are of considerable economic and ecological importance. Sedges represent an ideal model family to study evolutionary biology because of their species richness, global distribution, large discrepancies in lineage diversity, broad range of ecological preferences, and adaptations including m...

The tree of life is the fundamental biological roadmap for navigating the evolution and properties of life on Earth, and yet remains largely unknown. Even angiosperms (flowering plants) are fraught with data gaps, despite their critical role in sustaining terrestrial life. Today, high-throughput sequencing promises to significantly deepen our under...

Unprecedented changes in the Earth’s biota are prompting urgent efforts to describe and conserve plant diversity. For centuries, botanical monographs — comprehensive systematic treatments of a family or genus — have been the gold standard for disseminating scientific information to accelerate research. The lack of a monograph compounds the risk tha...

Molecular phylogenetic studies based on Sanger sequences have shown that Cyperaceae tribe Fuireneae s.l. is paraphyletic. However, taxonomic sampling in these studies has been poor, topologies have been inconsistent, and support for the backbone of trees has been weak. Moreover, uncertainty still surrounds the morphological limits of Schoenoplectie...

Well-supported phylogenies are a prerequisite for the study of the evolution and diversity of life on earth. The subfamily Calamoideae accounts for more than one fifth of the palm family (Arecaceae), occurs in tropical rainforests across the world, and supports a billion-dollar industry in rattan products. It contains ca. 550 species in 17 genera,...

Morphological characterizations of genera in Cyperaceae tribe Abildgaardieae have been highly problematic and the subject of much debate. Earlier molecular phylogenetic studies based on Sanger sequencing and a limited sampling have indicated that several generic circumscriptions are not monophyletic. Here, we provide the first phylogenetic hypothes...

The Useful Plants and Fungi of Colombia project is a 2.5-year initiative led by Royal Botanic Gardens, Kew in collaboration with the Alexander von Humboldt Biological Resources Research Institute. Its aim is to develop pathways to enhance nature’s contribution to people in Colombia by increasing, consolidating and making accessible the knowledge of...

Madagascar fait partie des territoires les plus importants dans le monde en termes de diversité spécifique pour les palmiers ou la famille des Arecaceae. Sur les quelques 2800 espèces reconnues dans le monde, l'ile possède à elle seule 208 espèces natives dont plus de 98% en sont endémiques. Certains taxons sont uniques du point de vue biologique c...

Madagascar is one of the most important areas in the world in terms of species diversity for palms, the family Arecaceae. Out of the approximately 2500 species recognized in the world, the island alone has 208 indigenous species, of which more than 98% are endemic, found naturally nowhere else. Some taxa are unique from a biological point of view b...

The date palm ( Phoenix dactylifera ) has been a cornerstone of Middle Eastern and North African agriculture for millennia. It is presumed that date palms were first domesticated in the Persian Gulf and subsequently introduced into North Africa, where their evolution in the latter region appears to have been influenced by gene flow from the wild re...

Urera Gaudich, s.l. is a pantropical genus comprising c. 35 species of trees, shrubs, and vines. It has a long history of taxonomic uncertainty, and is repeatedly recovered as polyphyletic within a poorly resolved complex of genera in the Urticeae tribe of the nettle family (Urticaceae). To provide generic delimitations concordant with evolutionary...

Premise of the study Evolutionary relationships in the species-rich Orchidaceae have historically relied on organellar DNA sequences and limited taxon sampling. Previous studies provided a robust plastid-maternal phylogenetic framework, from which multiple hypotheses on the drivers of orchid diversification have been derived. However, the extent to...