Natural Selection Research Articles

Indicators of morphofunctional adaptation of modern youth from three regions of the world: Bantu (Tanzania), Russians and Buryats

Introduction. The problem of human adaptation to modern realities, including living in cities, changing the traditional diet, and significantly reducing physical stress on the body in everyday life is becoming increasingly relevant all over the world. In this vein, experts from various fields of science pay attention to the study of general secular trends and a more detailed analysis of individual components of this phenomenon, including body composition and other somatic characteristics of specific social and/or gender and age groups of the population. Of particular interest are data on urban populations that have recently migrated from rural areas, against the background of significant socio-economic transformations in the countries of the Global South, as well as a comparison of data from different regions of the world to identify common and population-specific indicators of adaptation. Materials and methods. The paper presents data on students from three populations (684 individuals, 343 of them men and 341 women): Tanzanian (natives of the Bantu peoples from Dodoma), Russian (residents of Tula) and Buryat (residents of Ulan-Ude). The age ranges from 17 to 30 years, the average age was 21.28±2.75 y. A number of anthropometric characteristics and body composition were measured. Results. Our data indicate the presence of sexual dimorphism in each of the studied populations according to the complex of morphological characteristics and body composition. It is noteworthy that Russian students (Caucasians) had more pronounced sexual dimorphism compared to Tanzanians (Negroids) and Buryats (Mongoloids). Conclusion. Summing up, data on three populations representing samples of young people who are similar in social status and level of education, but differ in their racial and ethnic origin, as well as the environmental characteristics of the regions of residence, indicate the presence of distinct differences between the sexes in body size and its component composition. These differences were unidirectional in the three samples studied, and may reflect the generalized outcome of natural and sexual selection for Homo sapiens.

Comparative Analysis of the Codon Usage Pattern in the Chloroplast Genomes of Gnetales Species

Codon usage bias refers to the preferential use of synonymous codons, a widespread phenomenon found in bacteria, plants, and animals. Codon bias varies among species, families, and groups within kingdoms and between genes within an organism. Codon usage bias (CUB) analysis sheds light on the evolutionary dynamics of various species and optimizes targeted gene expression in heterologous host plants. As a significant order of gymnosperms, species within Gnetales possess extremely high ecological and pharmaceutical values. However, comprehensive analyses of CUB within the chloroplast genomes of Gnetales species remain unexplored. A systematic analysis was conducted to elucidate the codon usage patterns in 13 diverse Gnetales species based on the chloroplast genomes. Our results revealed that chloroplast coding sequences (cp CDSs) in 13 Gnetales species display a marked preference for AT bases and A/T-ending codons. A total of 20 predominantly high-frequency codons and between 2 and 7 optimal codons were identified across these species. The findings from the ENC-plot, PR2-plot, and neutrality analyses suggested that both mutation pressure and natural selection exert influence on the codon bias in these 13 Gnetales species, with natural selection emerging as the predominant influence. Correspondence analysis (COA) demonstrated variation in the codon usage patterns among the Gnetales species and indicated mutation pressure is another factor that could impact CUB. Additionally, our research identified a positive correlation between the measure of idiosyncratic codon usage level of conservatism (MILC) and synonymous codon usage order (SCUO) values, indicative of CUB’s potential influence on gene expression. The comparative analysis concerning codon usage frequencies among the 13 Gnetales species and 4 model organisms revealed that Saccharomyces cerevisiae and Nicotiana tabacum were the optimal exogenous expression hosts. Furthermore, the cluster and phylogenetic analyses illustrated distinct patterns of differentiation, implying that codons, even with weak or neutral preferences, could affect the evolutionary trajectories of these species. Our results reveal the characteristics of codon usage patterns and contribute to an enhanced comprehension of evolutionary mechanisms in Gnetales species.

Evolution of Sensory Receptors.

Sensory receptors are at the interface between an organism and its environment and thus represent key sites for biological innovation. Here, we survey major sensory receptor families to uncover emerging evolutionary patterns. Receptors for touch, temperature, and light constitute part of the ancestral sensory toolkit of animals, often predating the evolution of multicellularity and the nervous system. In contrast, chemoreceptors exhibit a dynamic history of lineage-specific expansions and contractions correlated with the disparate complexity of chemical environments. A recurring theme includes independent transitions from neurotransmitter receptors to sensory receptors of diverse stimuli from the outside world. We then provide an overview of the evolutionary mechanisms underlying sensory receptor diversification and highlight examples where signatures of natural selection are used to identify novel sensory adaptations. Finally, we discuss sensory receptors as evolutionary hotspots driving reproductive isolation and speciation, thereby contributing to the stunning diversity of animals.

Life, Death and Energy: What Does Nature Select?

Evolutionary biology is poised for a third major synthesis. The first presented Darwin's evidence from natural history. The second incorporated genetic mechanisms. The third will be based on energy and biophysical processes. It should include the equal fitness paradigm (EFP), which quantifies how organisms convert biomass into surviving offspring. Natural selection tends to maximise energetic fitness, , where is mass-specific rate of cohort biomass production, is generation time, is fraction of cohort production that is passed to surviving offspring, and is energy density of biomas. At steady state, parents replace themselves with offspring of equal mass-specific energy content, ≈ 22.4 kJ/g, and biomass, ≈ 1 g/g. The EFP highlights: (i) the energetic basis of survival and reproduction; (ii) how natural selection acts directly on the parameters of ; (iii) why there is no inherent intrinsic fitness advantage for higher metabolic power, ontogenetic or population growth rate, fecundity, longevity, or resource use efficiency; and (iv) the role of energy in animals with a variety of life histories. Underlying the spectacular diversity of living things is pervasive similarity in how energy is acquired from the environment and used to leave descendants offspring in future generations.

Predictability and evolutionary determinism — the search for quantitative explanation

Physics describes reality through the understanding and elucidation of physical laws. From these laws, the universe is predictable. It has indeed been suggested that explanation of observable phenomena comes from our ability to predict these events, through our understanding of physical laws and causal processes. Biological entities operate, of course, through physical and chemical laws. But there exist biological processes that have emergent properties, notably the evolution of adaptation through natural selection, which add an extra dimension to the concept of the understanding of biological phenotypes. The population genetic theory of evolution is mathematically formulated, and contains elements of determinism, typified by the action of natural selection, and elements of randomness, typified by the action of genetic drift and by the randomness of mutation. But is the goal-directed property of natural selection sufficient to conclude that the deterministic elements of the evolutionary process make evolutionary change predictable? And to what extent can we expect 'adaptation' to function as an explanation of biological phenotypes?

Population structure and natural selection across a flower color polymorphism in the desert plant Encelia farinosa.

Clines-or the geographic sorting of phenotypes across continual space-provide an opportunity to understand the interaction of dispersal, selection, and history in structuring polymorphisms. In this study, we combine field-sampling, genetics, climatic analyses, and machine learning to understand a flower color polymorphism in the wide-ranging desert annual Encelia farinosa. We find evidence for replicated transitions in disk floret color from brown to yellow across spatial scales, with the most prominent cline stretching ~100 km from southwestern United States into México. Because population structure across the cline is minimal, selection is more likely than drift to have an important role in determining cline width. Given that the cline aligns with a climatic transition but there is no evidence for pollinator preference for flower color, we hypothesize that floret color likely varies as a function of climatic conditions.

The Evolution of Mate Attachment.

AbstractWhether natural selection leads to attachment in monogamous pair bonds has seldom been addressed. Operationally defining attachment as a behavioral modifier that decreases divorce probability with pair duration, we develop a model for the evolution of attachment. If divorce (the ending of a pair bond when both individuals survive to the next breeding season) is more likely to occur out of poor-quality reproductive opportunities (i.e., poor territory or low-quality mate), individuals in experienced pairs are more likely to be found in high-quality opportunities. Consequently, when divorce decisions occur using imperfect information from reproductive success, pair duration provides individuals with information about the quality of their reproductive opportunity and attachment can evolve. We show that high survival rates, divorce propensities, and probabilities of nest failure favor the evolution of attachment. Attachment is also more likely to evolve when individuals can directly assess the quality of their reproductive opportunity (as opposed to relying on imperfect information from reproductive success), when the quality of the reproductive opportunity has adult survival ramifications, and when divorce coevolves with attachment. We show that our core conclusions are robust to a variety of assumptions using individual-based simulations. Our results clarify how attachment can be adaptive and suggest that studying pair bonds as dynamic entities is a promising avenue for future work.

Perception, Evolution, and the Explanatory Scope of Scientific Theories

According to the interface theory of perception, our perceptual systems have evolved to provide a species-specific interface to guide adaptive behaviour, and not to provide veridical representations of an observer-independent world. Results of simulations of evolutionary resource games, genetic algorithms, and multiple mathematical theorems have supported and fleshed out this claim in various ways. They indicate that the probability is zero that any perceptual system has been shaped by natural selection to represent the true structure of an observer-independent world. Bagwell (2023) thinks that this argument is self-defeating because it implies that organisms, resources, genes, etc. that are essential constituents of Darwin's theory do not provide an insight into the nature of observerindependent reality. Bagwell's argument relies on a false premise, however — namely, that the mathematical formulation of a scientific theory cannot dethrone its fundamental concepts. More broadly, his argument involves a fundamental misunderstanding of the nature of scientific theories — of their explanatory scope and their necessary limits.

Early Life History Divergence Mediates Elevational Adaptation in a Perennial Alpine Plant

ABSTRACTSpatially divergent natural selection can drive adaptation to contrasting environments and thus the evolution of ecotypes. In perennial plants, selection shapes life history traits by acting on subsequent life stages, each contributing to fitness. While evidence of adaptation in perennial plants is common, the expression of life history traits is rarely characterized, limiting our understanding of their role in adaptive evolution. We conducted a multi‐year reciprocal transplant experiment with seedlings from low and high elevation populations of the alpine carnation Dianthus carthusianorum to test for adaptation linked to contrasting climates and inferred specific contributions of early life stages to fitness. We assessed genotype by environment interactions in single fitness components, applied matrix population models to achieve an integrated estimate of fitness through population growth rates, and performed trade‐off analyses to investigate the advantage of alternate life history traits across environments. We found evidence of genotype by environment interactions consistent with elevational adaptation at multiple stages of the early life cycle. Estimates of population growth rates corroborated a strong advantage of the local genotype. Early reproduction and survival are alternate major contributors to adaptation at low and high elevation, respectively, and are linked by trade‐offs that underlie the evolution of divergent life history traits across environments. While these traits have a strong genetic basis, foreign populations express co‐gradient plasticity, reflecting the adaptive strategy of the local populations. Our study reveals that selection associated to climate has driven the evolution of divergent life histories and the formation of elevational ecotypes. While the high energy environment and strong competition favor investment in early reproduction at low elevation, limiting resources favor a more conservative strategy relying on self‐maintenance at high elevation. The co‐gradient plasticity expressed by high‐elevation populations may facilitate their persistence under warming climatic conditions.

Unravelling Prokaryotic Codon Usage: Insights from Phylogeny, Influencing Factors and Pathogenicity

Analyzing prokaryotic codon usage trends has become a crucial topic of study with significant ramifications for comprehending microbial genetics, classification, evolution, and the control of gene expression. This review study explores the numerous facets of prokaryotic codon usage patterns, looking at different parameters like habitat and lifestyle across broad groups of prokaryotes by emphasizing the role of codon reprogramming in adaptive strategies and its integration into systems biology. We also explored the numerous variables driving codon usage bias, including natural selection, mutation, horizontal gene transfer, codon-anticodon interaction, and genomic composition in prokaryotes through a thorough study of current literature. Furthermore, a special session on codon usage on pathogenic prokaryotes and the role of codon usage in the phylogeny of prokaryotes has been discussed. We also looked at the various software and indices that have been recently applied to prokaryotic genomes. The promising directions that lay ahead to map the future of codon usage research on prokaryotes have been emphasized. Codon usage variations across prokaryotic communities could be better understood by combining environmental, metagenomic, and system biology approaches.

Uneven Influx of European-Specific Alleles of SLC45A2, SLC24A5, TYRP1, DRD2, EDAR, and OCA2 Genes into the Gene Pool of the Koryaks

The distribution of alleles highly specific to Europeans in the Koryak gene pool, which formed as a result of intensive interethnic admixture in the Northern Priokhotie, characterized by the prevailing genetic contribution from males of Eastern European origin, was analyzed. The loci rs16891982 (SLC45A2 gene), rs1426654 (SLC24A5 gene), rs1408799 (TYRP1 gene), rs1076563 (DRD2 gene), rs3827760 (EDAR gene), and rs1448485 (OCA2 gene), which are mainly associated with the pigmentation system, were selected for analysis. High heterogeneity was found in the frequency of European-specific alleles, ranging from 1.4% for the variant rs1076563-C of the DRD2 gene to 14.7% for the variant rs1426654-A of the SLC24A5 gene. The reasons for the uneven influx of European-specific alleles into the Koryak gene pool are discussed. It is possible that the formation of genetic structure of modern Koryaks under intensive interethnic admixture was accompanied by the influence of natural selection on some parts of the genome.

Testing secondary sex ratio bias hypotheses in white-tailed deer in Mississippi, USA.

Natural selection favors individuals with the highest inclusive fitness (i.e., total number of descendants). In cases where one sex is more productive, one or both parents may maximize their inclusive fitness by investing in the offspring of the more prolific sex. Such preferential production can lead to skewed sex ratios at various life history stages, including at birth, resulting in secondary sex ratio bias. Several competing hypotheses have been proposed to explain observed variation in secondary sex ratios including Fisher's frequency dependence and two hypotheses related to maternal condition: Trivers-Willard and the local resource hypotheses. Although it has been shown that maternal condition can influence the number of offspring produced in white-tailed deer, there is no consensus as to which of the hypotheses drives sex ratio bias in wild populations. Using a spatiotemporally extensive dataset of pregnant white-tailed deer from Mississippi, USA, we examined fetal sex ratio in relation to the Fisherian frequency-dependence hypothesis and hypotheses related to maternal condition. While there was a male-sex ratio bias in pregnant females that reduced in intensity with the number of offspring, there was no support for condition-related hypotheses. Instead, secondary sex ratios for white-tailed deer in Mississippi were nearly consistent with Fisherian frequency dependence. Our findings add to the body of literature on secondary sex biases in white-tailed deer and help inform sex bias ratios for a southern population of a cervid of management importance in the US.

The origin and evolution of European eel rhabdovirus dominant genotype.

The Eel Virus European X (EVEX) is a significant pathogen contributing to the decline of eel populations. As an important evolutionary driving force, it is crucial to understand whether homologous recombination (HR)occurs between EVEXs for revealing the evolutionary patterns of the virus. This study indicates that HR may enhance genetic diversity and accelerate the evolution and spread of EVEX. Phylogenetic analysis reveals that the current popular EVEX is primarily composed of a dominant recombinant genotype. Further investigation suggests that recombination events, which likely occurred approximately 54 years ago, may alter codon preferences, highlighting the adaptive advantages this provides and enhancing the virus's ability to infect its eel host. The emergence of this advantageous genotype may be driven by environmental selection pressures, consistent with natural selection principles. In summary, our findings suggest that HR might plays an important role in EVEX evolution, facilitating its adaptation to changing environmental conditions.

Long‐Term Maintenance of Complex Chromosomal Inversion Polymorphism in Drosophila mediopunctata

ABSTRACTNatural selection is known to favor specific gene combinations, thereby shaping the evolution of recombination rates, often through epistatic interactions. However, the dynamics of these interacting factors within natural populations remain poorly understood. In this study, we investigate the long‐term maintenance of a complex polymorphism involving linked, nonoverlapping chromosomal inversions in a natural population of Drosophila mediopunctata. Remarkably, even after 30 years—equivalent to roughly 340 generations—two major features have remained unexpectedly stable: the linkage disequilibrium (LD) between inversions, which deviates significantly from the theoretical prediction of decay, and a consistent seasonal cycle pattern of heterozygous excess and homozygous deficiencies. We explored the roles of recombination suppression, epistatic selection, and overdominance in maintaining this stability, examining their alignment with previously described patterns. Our findings reveal that moderate selection coefficients, such as s = 0.0407, are sufficient to maintain the observed LD for the most common haplotypes, albeit leading to an unstable equilibrium. Simulations further reveal that the introduction of overdominance stabilizes the system, enabling the long‐term persistence of this complex inversion polymorphism across various frequency scenarios. The stability of this system appears to hinge on a delicate balance between LD, recombination rates, and selective pressures, with overdominance playing a critical role. Our findings highlight the significance of epistatic interactions and selective pressures in shaping evolutionary pathways in natural populations and offer a compelling example of natural selection acting on a complex inversion polymorphism, providing valuable insights into the evolutionary dynamics governing inversion systems.

An archaic HLA class I receptor allele diversifies natural killer cell-driven immunity in First Nations peoples of Oceania

Genetic variation in host immunity impacts the disproportionate burden of infectious diseases that can be experienced by First Nations peoples. Polymorphic human leukocyte antigen (HLA) class I and killer cell immunoglobulin-like receptors (KIRs) are key regulators of natural killer (NK) cells, which mediate early infection control. How this variation impacts their responses across populations is unclear. We show that HLA-A∗24:02 became the dominant ligand for inhibitory KIR3DL1 in First Nations peoples across Oceania, through positive natural selection. We identify KIR3DL1∗114, widespread across and unique to Oceania, as an allele lineage derived from archaic humans. KIR3DL1∗114+NK cells from First Nations Australian donors are inhibited through binding HLA-A∗24:02. The KIR3DL1∗114 lineage is defined by phenylalanine at residue 166. Structural and binding studies show phenylalanine 166 forms multiple unique contacts with HLA-peptide complexes, increasing both affinity and specificity. Accordingly, assessing immunogenetic variation and the functional implications for immunity are fundamental toward understanding population-based disease associations.

Characterising the Genomic Landscape of Differentiation Between Annual and Perennial Rye.

Annuality and perenniality represent two different life-history strategies in plants, and an analysis of genomic differentiation between closely related species of different life histories bears the potential to identify the underlying targets of selection. Additionally, understanding the interactions between patterns of recombination and signatures of natural selection is a central aim in evolutionary biology, because patterns of recombination shape the evolution of genomes by affecting the efficacy of selection. Here, our aim was to characterise the landscape of genomic differentiation between weedy annual rye (Secale cereale L.) and wild perennial rye (Secale strictum C. Presl), and explore the extent to which signatures of selection are influenced by recombination rate variation. We used population-level sequence data of annual and perennial rye to analyse population structure and their demographic history. Based on our analyses, annual and perennial rye diverged approximately 26,500 years ago (ya) from an ancestral population size of ~85,000 individuals. We analysed patterns of genetic diversity and genetic differentiation, and found highly differentiated regions located in low-recombination regions, indicative of linked selection. Although all highly differentiated regions, as revealed by F ST-outlier scans, were located in low-recombining regions, not all chromosomes showed this tendency. We therefore performed a gene ontology enrichment analysis, which showed that highly differentiated regions comprise genes involved in photosynthesis. This enrichment was confirmed when F ST outlier scans were performed separately in low- and intermediate-recombining regions, but not in high-recombining regions, suggesting that local recombination rate variation in rye affects outlier scans. Cultivated rye is an annual crop, but the introduction of perenniality may be advantageous in regions with poor soil quality or under low-input farming. Although the resolution of our analysis is limited to a broad-scale, knowledge about the evolutionary divergence between annual and perennial rye might support breeding efforts towards perennial rye cultivation.

Climate change reduces the tension of conflicting selection pressures on breeding date in a passerine bird.

Unpredictably fluctuating environments create complex selective landscapes that shape the distribution of key life history traits. Identifying the mechanisms behind dynamic patterns of selection is difficult, yet essential for predicting responses to climate change. We combine long-term measures with field manipulation of natural selection on breeding date in a wild bird to investigate whether highly variable spring cold snaps drive fluctuating selection. We show that variation in cold snap intensity leads to fluctuating selection on breeding date-in weak cold snap years, selection was consistently negative; however, in strong cold snap years, its direction reversed. These patterns were mirrored in a field experiment; nests that were food supplemented during cold snaps avoided cold snap mortality leading earlier breeders to have higher fitness. In contrast, in the non-supplemented group earlier breeders had higher cold snap nest mortality and selection was positive. Using nearly a century of climate data, we show that cold snaps are becoming less frequent and paradoxically occurring later which should allow earlier breeders to avoid them, potentially releasing conflicting selection pressures and facilitating a rapid phenological shift. Thus, rather than constraining a species' ability to adapt, climate change can enable a rapid shift to a new phenotypic optimum.

A review of Dr Wrangham’s book, ‘the Goodness Paradox . . . ‘, and insights into the evolution of human language, aesthetics, and free will

Dr Richard Wrangham’s book and YouTubes are helping to explain our evolved psychology as primarily occurring in African hunter-gatherer bands before the end of the last ice age. This perspective is supported by the exquisite cave paintings and tool artifacts from this ancient time. The most important evidence about our origins, however, comes from recent anthropological studies of current bands that represent the earlier age. Results showed that 5-psychosocial-behaviors produced both the environment and the natural selection for our psychology. These are: 1) language, coalitional activities and egalitarianism organization, 2) problems of bullies for egalitarianism, 3) management of the problems by gossip, ostracism and executions, 4) those targeted by the management had shorter lives and fewer children demonstrating strong natural selection, 5) reduced targeting occurred for those showing high-quality activities or high status, which increased the complexity of the selection to include all of our psychological abilities. The evolved psychological abilities include those highlighted by Dr Wrangham: emotions, intelligence, conscience and personality, as well as those with only supporting evidence: developmental and social learning, theory of mind, language, aesthetics, and free will. Further support for the importance of the 5-psychosocial-behaviors is provided by evidence from the domestication syndrome, natural selection pressure, and a positive feedback model. In addition, these perspectives can explain issues such as why 50% of our thoughts and behaviors comes from our environment and development as demonstrated in identical twin studies, and why we experience life with agency and free will. Dr Wrangham’s work is producing a new explanation of our nature that can help us all to understand why we are the way we are.

Comparative analyses of plastomes in Allaeanthus and Malaisia: structure, evolution, and phylogeny.

The small genera Allaeanthus and Malaisia within the Moraceae have important edible, medicinal, and economic value. However, complete plastome blueprints and a well-resolved evolutionary history of these two genera are still lack, thereby limiting their conservation and application. The recent discovery of a new distribution of Allaeanthus kurzii in Hainan, China, marked by the collection of two unique samples, alongside three samples of Malaisia scandens, has opened new avenues for research. This study aimed to compare the Allaeanthus and Malaisia plastomes of Hainan Province samples with those of samples from other regions, focusing on plastome structure, codon usage bias, natural selection, and the evolutionary history of A. kurzii and M. scandens. The results showed that both species had a quadripartite plastome structure, with sizes ranging from 162,134 to 162,170bp for A. kurzii and 161,235 to 162,134bp for M. scandens. Both species displayed loss of the infA gene and reduction of the rpl22 gene. Two highly variable regions (petD-trnD-GUC and rpl20-clpP) and three highly variable genes (rpl20, petB, and rpl16) were identified in A. kurzii, while two highly variable regions (ycf2-ndhB and ccsA-ndhE) and three highly variable genes (psbT, rpl36, and ycf2) were found in M. scandens. The protein-coding sequences (CDSs) of the Allaeanthus and Malaisia plastomes exhibited similar patterns of adaptive indices and codon usage frequencies. The genes associated with photosynthesis underwent strong purifying selection. Phylogenetic analysis revealed that Allaeanthus, Broussonetia, and Malaisia constituted a monophyletic group, with Malaisia being more closely related to Broussonetia. Broussonetia diversified approximately 19.78 million years ago, Malaisia approximately 4.74 million years ago, and Allaeanthus approximately 16.18 million years ago. These new plastome-based discoveries will guide conservation planners and medicinal plant breeders and genetic resource development for these species in the region.

Evolution of plant metabolism: the state-of-the-art.

Immense chemical diversity is one of the hallmark features of plants. This chemo-diversity is mainly underpinned by a highly complex and biodiverse biochemical machinery. Plant metabolic enzymes originated and were inherited from their eukaryotic and prokaryotic ancestors and further diversified by the unprecedentedly high rates of gene duplication and functionalization experienced in land plants. Unlike prokaryotic microbes, which display frequent horizontal gene transfer events and multiple inputs of energy and organic carbon, land plants predominantly rely on organic carbon generated from CO2 and have experienced relatively few gene transfers during their recent evolutionary history. As such, plant metabolic networks have evolved in a stepwise manner using existing networks as a starting point and under various evolutionary constraints. That said, until recently, the evolution of only a handful of metabolic traits had been extensively investigated and as such, the evolution of metabolism has received a fraction of the attention of, the evolution of development, for example. Advances in metabolomics and next-generation sequencing have, however, recently led to a deeper understanding of how a wide range of plant primary and specialized (secondary) metabolic pathways have evolved both as a consequence of natural selection and of domestication and crop improvement processes. This article is part of the theme issue 'The evolution of plant metabolism'.