Guillaume Chomicki

• BSc (Manchester), Dr.rer.Nat (Munich).
• Professor (Full) at Durham University

Significance Some epiphytes gain most of their nutrients from ants that nest in plant-provided cavities, accessible only through plant-formed entrance holes. We use a large clade of such epiphytes to study when mutualisms break down and how this affects the symbiont filtering system. Results support three theoretical predictions: ( i ) only general...

Significance In human cultivation systems, farmers increasingly use technology to gather data for evaluating tradeoffs between diverse—and sometimes conflicting—crop requirements to maximize yield. Some social insects have also evolved agricultural practices, but it is unknown how they evaluate local conditions to balance conflicting crop requireme...

While the importance of mutualisms across the tree of life is recognized, it is not understood why some organisms evolve high levels of dependence on mutualistic partnerships, while other species remain autonomous or retain or regain minimal dependence on partners.We identify four main pathways leading to the evolution of mutualistic dependence. Th...

Significance Wild progenitors of crops are important resources for breeding and for understanding domestication, but identifying them is difficult. Using an integrative approach, we discovered that a Sudanese form of melon with nonbitter whitish pulp, known as the Kordofan melon, is the closest relative of domesticated watermelons and a possible pr...

The Andes are the world's most biodiverse mountain chain, encompassing a complex array of ecosystems from tropical rainforests to alpine habitats. We provide a synthesis of Andean vascular plant diversity by estimating a list of all species with publicly available records, which we integrate with a phylogenetic dataset of 14 501 Neotropical plant s...

Distributed across two continents and thousands of islands, the Asian tropics are among the most species-rich areas on Earth. The origins of this diversity, however, remain poorly understood. Here, we reveal and classify contributions of individual tropical Asian regions to their overall diversity by leveraging species-level phylogenomic data and n...

Cancer is one of the deadliest human diseases. In 2020 alone, nearly 19.3 million cancer cases and 10.0 million deaths were recorded (1). Global spending on cancer drugs reached US$164 billion and is expected to rise to US$269 billion by 2025 (2). Natural compounds from plants, such as paclitaxel and camptothecin, have been demonstrated to be effec...

Orchids constitute one of the most spectacular radiations of flowering plants. However, their origin, spread across the globe, and hotspots of speciation remain uncertain due to the lack of an up‐to‐date phylogeographic analysis. We present a new Orchidaceae phylogeny based on combined high‐throughput and Sanger sequencing data, covering all five s...

Mutualisms have driven the evolution of extraordinary structures and behavioural traits, but their impact on traits beyond those directly involved in the interaction remains unclear. We addressed this gap using a highly evolutionarily replicated system – epiphytes in the Rubiaceae forming symbioses with ants. We employed models that allow us to tes...

Composite traits involve multiple components that, only when combined, gain a new synergistic function. Thus, how they evolve remains a puzzle. We combined field experiments, microscopy, chemical analyses, and laser Doppler vibrometry with comparative phylogenetic analyses to show that two carnivorous Nepenthes pitcher plant species independently e...

Mimicry is the phenomenon in which one species (the mimic) closely resembles another (the model), enhancing its own fitness by deceiving a third party into interacting with it as if it were the model. In plants, mimicry is used primarily to gain fitness by withholding rewards from mutualists or deterring herbivores cost‐effectively. While extensive...

What grows where? Knowledge about where to find particular species in nature must have been key to the survival of humans throughout our evolution. Over time, and as people colonised new land masses and habitats, interactions with the local biota led to a wealth of combined traditional and scientific wisdom about the distributions of species and th...

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...

Examples of predator-prey interactions in which flies rob ants are uncommon. To date, this behavior has only been recorded in the genus Bengalia Robineau-Desvoidy (Bengaliinae, Diptera, Calliphoridae). These predatory flies ambush ants, and rob them of the food or offspring that they are carrying. However, because of the rarity of this behavior, th...

Outside humans, true agriculture was previously thought to be restricted to social insects farming fungus. However, obligate farming of plants by ants was recently discovered in Fiji, prompting a re-examination of plant cultivation by ants. Here, we generate a database of plant cultivation by ants, identify three main types, and show that these int...

The origins and evolution of the outstanding Neotropical biodiversity are a matter of intense debate. A comprehensive understanding is hindered by the lack of deep-time comparative data across wide phylogenetic and ecological contexts. Here, we quantify the prevailing diversification trajectories and drivers of Neotropical diversification in a samp...

Iconographic evidence from Egypt suggests that watermelon pulp was consumed there as a dessert by 4,360 BP. Earlier archaeobotanical evidence comes from seeds from Neolithic settlements in Libya, but whether these were watermelons with sweet pulp or other forms is unknown. We generated genome sequences from 6,000- and 3,300-yr-old seeds from Libya...

Contributors explore common elements in the evolutionary histories of both human and insect agriculture resulting from convergent evolution. During the past 12,000 years, agriculture originated in humans as many as twenty-three times, and during the past 65 million years, agriculture also originated in nonhuman animals at least twenty times and in...

The rare ant‐plant Anthorrhiza echinella C.R.Huxley & Jebb from Papua New Guinea is described and illustrated. The outlook of the species and the importance of ex situ conservation strategies for this and other ant‐plants are discussed in the context of botanic garden collections. Based on the plant's likely current distribution, we have assessed t...

Farming of fungi by ants, termites, or beetles has led to ecologically successful societies fueled by industrial-scale food production. Another type of obligate insect agriculture in Fiji involves the symbiosis between the ant Philidris nagasau and epiphytes in the genus Squamellaria (Rubiaceae) that the ants fertilize, defend, harvest, and depend...

Societal Impact Statement The watermelon (Citrullus lanatus subsp. vulgaris) is among the world's most important fruit crops. We here use C‐14 dating and morphometric analysis to test whether ancient seeds can be identified to species level, which would help document food expansion, innovation, and diversity in Northeastern Africa. We dated a Libya...

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...

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...

This article is a Commentary on Anest et al. (2021), 231: 1278–1295.

Vespicochory, defined as seed dispersal by wasps, was first reported by Pellmyr (1985). To date, vespicochory has only been documented in nine plant species belonging to five plant families, themselves dispersed by five wasp genera (Burge and Beck 2019; Chen et al. 2020). All known wasp-dispersed plants bear seeds with lipid-rich elaiosomes that ar...

The origin of the outstanding Neotropical biodiversity is still debated. A comprehensive understanding is hindered by the lack of deep-time comparative data across wide phylogenetic and ecological contexts. Here we define and evaluate four evolutionary scenarios assuming different diversity trajectories and drivers of Neotropical diversification. R...

The mega-diversity of herbivorous insects is attributed to their co-evolutionary associations with plants. Despite abundant studies on insect-plant interactions, we do not know whether host-plant shifts have impacted both genomic adaptation and species diversification over geological times. We show that the antagonistic insect-plant interaction bet...

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,...

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...

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...

Across the tree of life, hosts have evolved mechanisms to control and mediate interactions with symbiotic partners. We suggest that the evolution of physical structures that allow hosts to spatially separate symbionts, termed compartmentalization, is a common mechanism used by hosts. Such compartmentalization allows hosts to: (i) isolate symbionts...

The exuberant proliferation of herbivorous insects is attributed to their associations with plants. Despite abundant studies on insect-plant interactions, we do not know whether host-plant shifts have impacted both genomic adaptation and species diversification over geological times. We show that the antagonistic insect-plant interaction between sw...

Orchids are globally distributed, a feature often attributed to their tiny dustlike seeds. They were ancestrally terrestrial but in the Eocene expanded into tree canopies, with some lineages later returning to the ground, providing an evolutionarily replicated system. Because seeds are released closer to the ground in terrestrial species than in ep...

Squamellaria is a genus of epiphytic Rubiaceae which has been domesticated by ants on the Fiji islands. One species is on the verge of extinction.

Some of the World's most valuable crops, including watermelon, honey melon, cucumber, squash, zucchini and pumpkin, belong to the family Cucurbitaceae. We review insights on their domestication from new phylogenies, archaeology and genomic studies. Ancestral state estimation on the most complete Cucurbitaceae phylogeny to date suggests that an annu...

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True agriculture – defined by habitual planting, cultivation, harvesting and dependence of a farmer on a crop – is known from fungi farmed by ants, termites or beetles, and plants farmed by humans or ants. Because farmers supply their crops with nutrients, they have the potential to modify crop nutrition over evolutionary time. Here we test this hy...

Domestication of the watermelon ( Citrullus lanatus ) has alternatively been placed in South Africa, the Nile valley, or more recently West Africa, with the oldest archeological evidence coming from Libya and Egypt. The geographic origin and domestication of watermelons has therefore remained unclear. Using extensive nuclear and plastid genomic dat...

Mutualisms – cooperative interactions among different species – are known to influence global biodiversity. Nevertheless, theoretical and empirical work has led to divergent hypotheses about how mutualisms modulate diversity. We ask here when and how mutualisms influence species richness. Our synthesis suggests that mutualisms can promote or restri...

In most seed plants, leaf size is isometrically related to stem cross-sectional area, a relationship referred to as Corner’s rule. When stems or leaves acquire a new function, for instance in ant-plant species with hollow stems occupied by ants, their scaling is expected to change. Here we use a lineage of epiphytic ant-plants to test how the evolu...

Martins et al 2018 Supp. tables "From tree tops to the ground: Reversals to terrestrial habit in Galeandra orchids (Epidendroideae: Catasetinae)"

Martins et al 2018 Supp. figures "From tree tops to the ground: Reversals to terrestrial habit in Galeandra orchids (Epidendroideae: Catasetinae)"

The placement of angiosperms and Gnetales in seed plant phylogeny remains one of the most enigmatic problems in plant evolution, with morphological analyses (which have usually included fossils) and molecular analyses pointing to very distinct topologies. Almost all morphology-based phylogenies group angiosperms with Gnetales and certain extinct se...

The colonization of the epiphytic niche of neotropical forest canopies played an important role in orchid's extraordinary diversification, with rare reversions to the terrestrial habit. To understand the evolutionary context of those reversals, we investigated the diversification of Galeandra, a Neotropical orchid genus which includes epiphytic and...

Differing from most animals, plants have an indeterminate body plan, allowing them to add new body parts throughout their lifetime. The realized modular construction of a plant is the result of endogenous processes and exogenous constraints. Plant architectural analysis provides a holistic approach to whole-plant development by disentangling endoge...

Poster presented on World Orchid Congress, Guayaquil, Ecuador, november 2017

Watermelons are among the most important vegetable crops worldwide, but targeted breeding is hindered by problems with Citrullus taxonomy. Here we clarify nomenclature and species relationships in Citrullus, its chromosome numbers, and the likely geographic region of watermelon domestication. We correct an erroneous chromosome count in recent liter...

The colonization of the epiphytic niche of tropical forest canopies played an important role in orchid’s extraordinary diversification in the Neotropics. However, reversals to the terrestrial habit occurred sparsely in species of Epidendroideae. To better understand which factors might have been involved in reversals to terrestrial habits in the pr...

Background: In contrast to most animals, plants have an indeterminate body plan, which allows them to add new body parts during their lifetime. A plant's realized modular construction is the result of exogenous constraints and endogenous processes. This review focuses on endogenous processes that shape plant architectures and their evolution. Sco...

Environmental sex determination (ESD) − a change in sexual function during an individual life span driven by environmental cues − is an exceedingly rare sexual system among angiosperms. Because ESD can directly affect reproduction success, it could influence diversification rate as compared with lineages that have alternative reproductive systems....

Recent advances in molecular phylogenetics and a series of important palaeobotanical discoveries have revolutionized our understanding of angiosperm diversification. Yet, the origin and early evolution of their most characteristic feature, the flower, remains poorly understood. In particular, the structure of the ancestral flower of all living angi...

Environmental sex determination (ESD) a change in sexual function during an individual life span driven by environmental cues is an exceedingly rare sexual system among angiosperms. Because ESD can directly affect reproduction success, it could influence diversification rate as compared with lineages that have alternative mating systems. Here we te...

The Andean uplift is one of the major orographic events in the New World and has impacted considerably the diversification of numerous Neotropical lineages. Despite its importance for biogeography, the specific role of mountain ranges as a dispersal barrier between South and Central American lowland plant lineages is still poorly understood. The sw...

The Andean mountains of South America are the most species-rich biodiversity hotspot worldwide with c. 15% of the world’s plant species, in only 1% of the world’s land surface. Orchids are a key element of the Andean flora, and one of the most prominent components of the Neotropical epiphyte diversity, yet very little is known about their origin an...

The placement of angiosperms and Gnetales in seed plant phylogeny remains one of the most enigmatic problems in plant evolution, with morphological analyses (which have usually included fossils) and molecular analyses pointing to very distinct topologies. Almost all morphology-based phylogenies group angiosperms with Gnetales and certain extinct se...