Domestication as a model system for the extended evolutionary synthesis

High-throughput DNA sequence analysis elucidates novel insight into the genetic basis of adaptation in local sheep

Understanding how evolutionary factors related to climate adaptation and human selection have influenced the genetic architecture of domesticated animals is of great interest in biology. In the current study, by using 304 whole genomes from different geographical regions (including Europe, north Africa, Southwest Asia, east Asia, west Africa, south Asia, east Africa, Australia and Turkey), We evaluate global sheep population dynamics in terms of genetic variation and population structure. We further conducted comparative population analysis to study the genetic underpinnings of climate adaption to local environments and also morphological traits. In order to identify genomic signals under selection, we applied fixation index (FST) and also nucleotide diversity (θπ) statistical measurements. Our results revealed several candidate genes on different chromosomes under selection for local climate adaptation (e.g. HOXC12, HOXC13, IRF1, FGD2 and GNAQ), body size (PDGFA, HMGA2, PDE3A) and also morphological related traits (RXFP2). The discovered candidate genes may offer newel insights into genetic underpinning of regional adaptation and commercially significant features in local sheep.

Needs for a conceptual bridge between biological domestication and early food globalization

The past 15 y has seen much development in documentation of domestication of plants and animals as gradual traditions spanning millennia. There has also been considerable momentum in understanding the dispersals of major domesticated taxa across continents spanning thousands of miles. The two processes are often considered within different theoretical strains. What is missing from our repertoire of explanations is a conceptual bridge between the protracted process over millennia and the multiregional, globally dispersed nature of domestication. The evidence reviewed in this paper bears upon how we conceptualize domestication as an episode or a process. By bringing together the topics of crop domestication and crop movement, those complex, protracted, and continuous outcomes come more clearly into view.

Could care giving have altered the evolution of human immune strategies?

Life history theory indicates that individuals/species with a slow pace of life invest more in acquired than innate immunity. Factors that decrease the pace of life and predict greater investment in acquired immunity include increased nutritional resources, increased pathogen exposure and decreased risk of extrinsic mortality. Common care behaviors given to sick individuals produce exactly these effects: provisioning increases nutritional resources; hygiene assistance increases disease exposure of carers; and protection can reduce the risk of extrinsic mortality to sick individuals. This study, therefore, investigated under what conditions care giving behaviors might impact immune strategy and pace of life. The study employed an agent-based model approach that simulated populations with varying levels of care giving, disease mortality, disease transmissibility, and extrinsic mortality, enabling measurements of how the immune strategy and age structure of the populations changed over evolutionary time. We used multiple regressions to examine the effects of these variables on immune strategy and the age structure of the population. The findings supported our predictions that care was selected for an acquired immunity. However, the pace of life did not slow as expected. Instead, the population shifted to a faster, but also more cost-intensive reproductive strategy in which care improved child survival by subsidizing the development of acquired immune responses.

Characteristic processes of human evolution caused the Anthropocene and may obstruct its global solutions

We propose that the global environmental crises of the Anthropocene are the outcome of a ratcheting process in long-term human evolution which has favoured groups of increased size and greater environmental exploitation. To explore this hypothesis, we review the changes in the human ecological niche. Evidence indicates the growth of the human niche has been facilitated by group-level cultural traits for environmental control. Following this logic, sustaining the biosphere under intense human use will probably require global cultural traits, including legal and technical systems. We investigate the conditions for the evolution of global cultural traits. We estimate that our species does not exhibit adequate population structure to evolve these traits. Our analysis suggests that characteristic patterns of human group-level cultural evolution created the Anthropocene and will work against global collective solutions to the environmental challenges it poses. We illustrate the implications of this theory with alternative evolutionary paths for humanity. We conclude that our species must alter longstanding patterns of cultural evolution to avoid environmental disaster and escalating between-group competition. We propose an applied research and policy programme with the goal of avoiding these outcomes. This article is part of the theme issue 'Evolution and sustainability: gathering the strands for an Anthropocene synthesis'.

Phylogenetic Analysis of Russian Native Sheep Breeds Based on mtDNA Sequences

Eurasia is represented by all climatic zones and various environments. A unique breed variety of farm animals has been developed in Russia, whose territory covers a large area of the continent. A total of 69 local breeds and types of dairy, wool, and meat sheep (Ovis aries) are maintained here. However, the genetic diversity and maternal origin of these local breeds have not been comprehensively investigated. In this study, we describe the diversity and phylogeny of Russian sheep breeds inhabiting different geographical regions based on the analysis of complete sequences of mitochondrial genomes (mtDNA). Complete mtDNA sequences of the studied sheep were obtained using next-generation sequencing technology (NGS). All investigated geographical groups of sheep were characterized by high haplotype (Hd = 0.9992) and nucleotide diversity (π = 0.00378). Analysis of the AMOVA results showed that genetic diversity was majorly determined by within-population differences (77.87%). We identified 128 haplotypes in all studied sheep. Haplotypes belonged to the following haplogroups: B (64.8%), A (28.9%), C (5.5%), and D (0.8%). Haplogroup B was predominant in the western part of Russia. A high level of mtDNA polymorphism in the studied groups of local sheep indicates the presence of a significant reserve of unique genotypes in Russia, which is to be explored.

Domestication and the comparative embryology of birds

Studies of domesticated animals have greatly contributed to our understanding of avian embryology. Foundational questions in developmental biology were motivated by Aristotle's observations of chicken embryos. By the 19th century, the chicken embryo was at the center stage of developmental biology, but how closely does this model species mirror the ample taxonomic diversity that characterizes the avian tree of life? Here, we provide a brief overview of the taxonomic breadth of comparative embryological studies in birds. We particularly focused on staging tables and papers that attempted to document the timing of developmental transformations. We show that most of the current knowledge of avian embryology is based on Galliformes (chicken and quail) and Anseriformes (duck and goose). Nonetheless, data are available for some ecologically diverse avian subclades, including Struthioniformes (e.g., ostrich, emu) and Sphenisciformes (penguins). Thus far, there has only been a handful of descriptive embryological studies in the most speciose subclade of Aves, that is, the songbirds (Passeriniformes). Furthermore, we found that temporal variances for developmental events are generally uniform across a consensus chronological sequence for birds. Based on the available data, developmental trajectories for chicken and other model species appear to be highly similar. We discuss future avenues of research in comparative avian embryology in light of the currently available wealth of data on domesticated species and beyond.

Exploring the role of ecology and social organisation in agropastoral societies: A Bayesian network approach

The present contribution focuses on investigating the interaction of people and environment in small-scale farming societies. Our study is centred on the particular way settlement location constraints economic strategy when technology is limited, and social division of work is not fully developed. Our intention is to investigate prehistoric socioeconomic organisation when farming began in the Old World along the Levant shores of Iberian Peninsula, the Neolithic phenomenon. We approach this subject extracting relevant information from a big set of ethnographic and ethnoarchaeological cases using Machine Learning methods. This paper explores the use of Bayesian networks as explanatory models of the independent variables-the environment- and dependent variables-social decisions-, and also as predictive models. The study highlights how subsistence strategies are modified by ecological and topographical variables of the settlement location and their relationship with social organisation. It also establishes the role of Bayesian networks as a suitable supervised Machine Learning methodology for investigating socio-ecological systems, introducing their use to build useful data-driven models to address relevant archaeological and anthropological questions.

Inferring cultural reproduction from lithic data: A critical review

The cultural reproduction of lithic technology, long an implicit assumption of archaeological theories, has garnered increasing attention over the past decades. Major debates ranging from the origins of the human culture capacity to the interpretation of spatiotemporal patterning now make explicit reference to social learning mechanisms and cultural evolutionary dynamics. This burgeoning literature has produced important insights and methodological innovations. However, this rapid growth has sometimes led to confusion and controversy due to an under-examination of underlying theoretical and methodological assumptions. The time is thus ripe for a critical assessment of progress in the study of the cultural reproduction of lithic technology. Here we review recent work addressing the evolutionary origins of human culture and the meaning of artifact variation at both intrasite and intersite levels. We propose that further progress will require a more extended and context-specific evolutionary approach to address the complexity of real-world cultural reproduction.

The Fits and Starts of Indian Rice Domestication: How the Movement of Rice Across Northwest India Impacted Domestication Pathways and Agricultural Stories

Rice is currently the staple food for over 3.5 billion people and is arguably the most important crop exploited by humans. Understanding how we came to the point where a single crop dominates the lives of almost half of the Earth’s population has major significance for our future, even more so given the climatic instability we face today, as rice is a cereal that is dependent on water to an extreme degree. In this study, the nature of early rice agriculture in South Asia is explored, looking at how this critical crop may have begun to be exploited, cultivated, and then brought under agricultural regimes during the long span between c.6500 and 1500 BC. There is now clear evidence for early Holocene cultivation of rice in the Middle Gangetic plains of northern India, but there is still considerable debate about the timing of when this cultivation began and whether it involved domestication of rice. By 3200 BC, however, rice agriculture was present outside the Ganges in the Indus Civilization. The data show accelerated domestication in the Indus environment and agricultural systems that played a part in later hybridization with the arrival of Chinese rice. Understanding how this move from its place of origin to a new environment may have become entangled in the domestication pathways of South Asia rice prior to the arrival of Chinese rice c.1500 BC are important to the overall rice story, as they play into modern concerns relating to biodiversity and different ways of growing and watering rice.

The evolution of the human healthcare system and implications for understanding our responses to COVID-19

The COVID-19 pandemic has revealed an urgent need for a comprehensive, multidisciplinary understanding of how healthcare systems respond successfully to infectious pathogens-and how they fail. This study contributes a novel perspective that focuses on the selective pressures that shape healthcare systems over evolutionary time. We use a comparative approach to trace the evolution of care-giving and disease control behaviours across species and then map their integration into the contemporary human healthcare system. Self-care and pro-health environmental modification are ubiquitous across animals, while derived behaviours like care for kin, for strangers, and group-level organizational responses have evolved via different selection pressures. We then apply this framework to our behavioural responses to COVID-19 and demonstrate that three types of conflicts are occurring: (1) conflicting selection pressures on individuals, (2) evolutionary mismatches between the context in which our healthcare behaviours evolved and our globalized world of today and (3) evolutionary displacements in which older forms of care are currently dispensed through more derived forms. We discuss the significance of understanding how healthcare systems evolve and change for thinking about the role of healthcare systems in society during and after the time of COVID-19-and for us as a species as we continue to face selection from infectious diseases.

Ornamental plant domestication by aesthetics-driven human cultural niche construction

Unlike plants that were domesticated to secure food, the domestication and breeding of ornamental plants are driven by aesthetic values. Here, we examine the major elements of the extended evolutionary synthesis (EES) theory that bridges the gap between the biology of ornamental plant domestication and the sociocultural motivations behind it. We propose that it involves specific elements of cumulative cultural evolution (CCE), plant gene-human culture coevolution (PGHCC), and niche construction (NC). Moreover, ornamental plant domestication represents an aesthetics-driven dimension of human niche construction that coevolved with socioeconomic changes and the adoption of new scientific technologies. Initially functioning as symbolic and aesthetic assets, ornamental plants became globally marketed material commodities as a result of the co-dependence of human CCE and prestige-competition motivations.

Pedagogical Ecology for an Alternative Sustainability: With Insights from Francis of Assisi and Contemporary Life Sciences

Sustainability is a widely discussed issue nowadays. The “human factor” appears to be the key to a suitable theory of sustainable development and, even more, to understanding the real scope of the issue at stake. We begin by highlighting that the issue of sustainability and the related ecological crisis ultimately stem from the fundamental view of the human–environment relationships. We tackle such a fundamental view from two apparently distant but converging perspectives: the one of Francis of Assisi (the patron saint of ecologists) and the one of contemporary advancements in evolutionary biology known as the “extended evolutionary theory” (EES). This will allow us to highlight how current life sciences ground a strong form of organism–environment complementarity—a core point for any allegedly comprehensive approach to sustainability and ecology. After that, we focus on recent developments in cultural evolution studies that see culture both as the driving force of (recent) human evolution and as the general context where the human–environment relationships take place and develop. Therefore, we argue that the environment exerts a powerful pedagogical influence on the human being and on humanity as a whole. We conclude by proposing a pedagogical criterion for ecology and sustainable development, according to which the modifications caused by the human being to the environment must be assessed (also) for their pedagogical import.

Disparities among crop species in the evolution of growth rates: the role of distinct origins and domestication histories

Growth rates vary widely among plants with different strategies. For crops, evolution under predictable and high-resource environments might favour rapid resource acquisition and growth, but whether this strategy has consistently evolved during domestication and improvement remains unclear. Here we report a comprehensive study of the evolution of growth rates based on comparisons among wild, landrace, and improved accessions of 19 herbaceous crops grown under common conditions. We also examined the underlying growth components and the influence of crop origin and history on growth evolution. Domestication and improvement did not affect growth consistently, that is growth rates increased or decreased or remained unchanged in different crops. Crops selected for fruits increased the physiological component of growth (net assimilation rate), whereas leaf and seed crops showed larger domestication effects on morphology (leaf mass ratio and specific leaf area). Moreover, climate and phylogeny contributed to explaining the effects of domestication and changes in growth. Crop-specific responses to domestication and improvement suggest that selection for high yield has not consistently changed growth rates. The trade-offs between morpho-physiological traits and the distinct origins and histories of crops accounted for the variability in growth changes. These findings have far-reaching implications for our understanding of crop performance and adaptation.

Bridging the explanatory gaps: What can we learn from a biological agency perspective?

We begin this article by delineating the explanatory gaps left by prevailing gene-focused approaches in our understanding of phenotype determination, inheritance, and the origin of novel traits. We aim not to diminish the value of these approaches but to highlight where their implementation, despite best efforts, has encountered persistent limitations. We then discuss how each of these explanatory gaps can be addressed by expanding research foci to take into account biological agency-the capacity of living systems at various levels to participate in their own development, maintenance, and function by regulating their structures and activities in response to conditions they encounter. Here we aim to define formally what agency and agents are and-just as importantly-what they are not, emphasizing that agency is an empirical property connoting neither intention nor consciousness. Lastly, we discuss how incorporating agency helps to bridge explanatory gaps left by conventional approaches, highlight scientific fields in which implicit agency approaches are already proving valuable, and assess the opportunities and challenges of more systematically incorporating biological agency into research programs.

Disentangling the Multidimensional Relationship between Livestock Breeds and Ecosystem Services

Simple Summary

Livestock breeds represent the diversity of livestock animals. They participate in the delivery of ecosystem services (ES), i.e., the benefits to humans provided by nature. In recent years, the contribution of livestock breeds to ES has received attention in livestock research. Additionally, there is increasing interest in integrating this knowledge into policies to make agriculture more sustainable. In this work, we elaborate on livestock breed characteristics that are key to the study of livestock breed contributions to ES. Thus, we explore the natural and human factors that have produced livestock breeds as ecologically and culturally mediated entities. In addition, we review the different roles of livestock breeds as biodiversity components. Finally, we examine how livestock breeds participate in livestock system heterogeneity. By integrating these aspects, we might better understand how livestock breeds provide and modulate ES provision and, therefore, how to improve breed conservation and livestock policies toward more sustainable farming.

Abstract

There is an increasing interest in assessing livestock breed contributions to ecosystem services (ES) and including this knowledge in decision making. However, this task has been limited due to the complexity of the multidimensional relationship between livestock diversity and ecosystem services. In this work, we elaborate on the livestock breed characteristics central to developing a comprehensive approach to livestock breed inclusion in the ecosystem services framework. Thus, we explore the multidimensional nature of livestock breeds, i.e., as eco-cultural entities, biodiversity components, and drivers of livestock system heterogeneity and functioning. First, anthropogenic and natural factors have acted jointly to develop breeds as eco-cultural entities. This fact represents an opportunity to move toward farming system sustainability by Nature-Based Solutions and Nature’s Contribution to People paradigms. Second, livestock breeds are components of biodiversity, and as such, can be framed as goods, as final ecosystem services, and as regulators of ecosystem processes. Third, livestock breeds contribute to livestock system heterogeneity and resilience. By integrating these aspects, we might better understand how livestock breeds provide and modulate ecosystem service provision and, therefore, how to improve breed conservation and livestock policies toward farming system sustainability.

Shifts in growth, but not differentiation, foreshadow the formation of exaggerated forms under chicken domestication

Domestication provides an outstanding opportunity for biologists to explore the underpinnings of organismal diversification. In domesticated animals, selective breeding for exaggerated traits is expected to override genetic correlations that normally modulate phenotypic variation in nature. Whether this strong directional selection affects the sequence of tightly synchronized events by which organisms arise (ontogeny) is often overlooked. To address this concern, we compared the ontogeny of the red junglefowl (RJF) (Gallus gallus) to four conspecific lineages that underwent selection for traits of economic or ornamental value to humans. Trait differentiation sequences in embryos of these chicken breeds generally resembled the representative ancestral condition in the RJF, thus revealing that early ontogeny remains highly canalized even during evolution under domestication. This key finding substantiates that the genetic cost of domestication does not necessarily compromise early ontogenetic steps that ensure the production of viable offspring. Instead, disproportionate beak and limb growth (allometry) towards the end of ontogeny better explained phenotypes linked to intense selection for industrial-scale production over the last 100 years. Illuminating the spatial and temporal specificity of development is foundational to the enhancement of chicken breeds, as well as to ongoing research on the origins of phenotypic variation in wild avian species.

The Effects of Domestication on the Brain and Behavior of the Chicken in the Light of Evolution

The avian class is characterized by particularly strong variability in their domesticated species. With more than 250 breeds and highly efficient commercial lines, domestic chickens represent the outcome of a really long period of artificial selection. One characteristic of domestication is the alterations in brain size and brain composition. The influence of domestication on brain morphology has been reviewed in the past, but mostly with a focus on mammals. Studies on avian species have seldom been taken into account. In this review, we would like to give an overview about the changes and variations in (brain) morphology and behavior in the domestic chicken, taking into consideration the constraints of evolutionary theory and the sense or nonsense of excessive artificial selection.

Theoretical plurality, the extended evolutionary synthesis, and archaeology

The study of cultural evolution now includes multiple theoretical frameworks. Despite common influence from Darwinian evolutionary theory, there is considerable diversity. Thus, we recognize those most influenced by the tenets of the Modern Synthesis (evolutionary archaeology, cultural transmission theory, and human behavioral ecology) and those most aligned more closely with concepts emerging in the Extended Evolutionary Synthesis (cultural macroevolution and evolutionary cognitive archaeology). There has been substantial debate between adherents of these schools of thought as to their appropriateness and priority for addressing the fundamentals of cultural evolution. I argue that theoretical diversity is necessary to address research questions arising from a complex archaeological record. Concepts associated with the Extended Evolutionary Synthesis may offer unique insights into the cultural evolutionary process.

Recent land use and management changes decouple the adaptation of livestock diversity to the environment

Native livestock breeds, i.e. those autochthonous to a specific region, are locally adapted domesticated animals that conserve genetic resources, guaranty food security and provide agroecosystem services. Native breeds are largely threatened worldwide by agricultural intensification and rural areas abandonment processes related to recent changes in production schemes and planning. Yet, our gap of knowledge regarding livestock breed-environment relationships may prevent the design of successful conservation measures. In this work, we analyse the links between livestock diversity -i.e. richness of native breeds- and a selection of environmental factors that express at broad scales, with a temporal perspective. We compare native breeds distributional patterns before and after the agricultural intensification, in the context of land-use change in mainland Spain. Our results confirm the existence of strong associations between the distribution of native livestock breeds and environmental factors. These links, however, weaken for contemporary distributions. In fact, changes in breed distribution reflect a shift towards more productive environments. Finally, we found that the areas having higher breed richness are undergoing land abandonment processes. Succeeding in the conservation of threatened native breeds will require going beyond merely genetic and production-oriented views. Ecological and sociocultural perspectives should also be accounted for as global change processes are determinant for livestock agrobiodiversity.

Disentangling the effects of sex, life history and genetic background in Atlantic salmon: growth, heart and liver under common garden conditions

Livestock domestication has long been a part of agriculture, estimated to have first occurred approximately 10 000 years ago. Despite the plethora of traits studied, there is little understanding of the possible impacts domestication has had on internal organs, which are key determinants of survival. Moreover, the genetic basis of observed associated changes in artificial environments is still puzzling. Here we examine impacts of captivity on two organs in Atlantic salmon (Salar salar) that have been domesticated for approximately 50 years: heart and liver, in addition to growth. We studied multiple families of wild, domesticated, F₁ and F₂ hybrid, and backcrossed strains of S. salar in replicated common garden tanks during the freshwater and marine stages of development. Heart and liver weight were investigated, along with heart morphology metrics examined in just the wild, domesticated and F₁ hybrid strains (heart height and width). Growth was positively linked with the proportion of the domesticated strain, and recombination in F₂ hybrids (and the potential disruption of co-adapted gene complexes) did not influence growth. Despite the influence of domestication on growth, we found no evidence for domestication-driven divergence in heart or liver morphology. However, sexual dimorphism was detected in heart morphology, and after controlling for body size, females exhibited significantly larger heart weight and heart width when compared with males. Wild females also had an increased heart height when compared with wild males, and this was not observed in any other strain. Females sampled in saltwater showed significantly larger heart height with rounder hearts, than saltwater males. Collectively, these results demonstrate an additive basis of growth and, despite a strong influence of domestication on growth, no clear evidence of changes in heart or liver morphology associated with domestication was identified.

Genes, culture, and the human niche: An overview

The sharp distinction between biological traits and culturally based traits, which had long been standard in evolutionary approaches to behavior, was blurred in the early 1980s by mathematical models that allowed a co-dependent evolution of genetic transmission and cultural information. Niche-construction theory has since added another contrast to standard evolutionary theory, in that it views niche construction as a cause of evolutionary change rather than simply a product of selection. While offering a new understanding of the coevolution of genes, culture, and human behavior, niche-construction models also invoke multivariate causality, which require multiple time series to resolve. The empirical challenge lies in obtaining time-series data on causal pathways involved in the coevolution of genes, culture, and behavior. This is a significant issue in archeology, where time series are often sparse and causal behaviors are represented only by proxies in the material record.

The extended evolutionary synthesis and human origins: Archaeological perspectives

Recent developments in evolutionary biology have led to a call for an extension of standard evolutionary theory, with its emphasis on processes such as selection and drift, into a much larger theoretical framework that includes processes such as niche construction, developmental plasticity, inclusive inheritance, and developmental bias. Skeptics argue that these processes are already subsumed within the standard theory and thus an extension is not required. Here, we outline what this evolutionary "rethink" might mean for the study of human origins. Specifically, can paleoanthropologists benefit from an extended theoretical toolkit? The papers in this special issue suggest it can be useful but may not be necessary, depending on the kinds of questions that are being asked.

Why Care: Complex Evolutionary History of Human Healthcare Networks

One of the striking features of human social complexity is that we provide care to sick and contagious individuals, rather than avoiding them. Care-giving is a powerful strategy of disease control in human populations today; however, we are not the only species which provides care for the sick. Widespread reports occurring in distantly related species like cetaceans and insects suggest that the building blocks of care for the sick are older than the human lineage itself. This raises the question of what evolutionary processes drive the evolution of such care in animals, including humans. I synthesize data from the literature to evaluate the diversity of care-giving behaviors and conclude that across the animal kingdom there appear to be two distinct types of care-behaviors, both with separate evolutionary histories: (1) social care behaviors benefitting a sick individual by promoting healing and recovery and (2) community health behaviors that control pathogens in the environment and reduce transmission within the population. By synthesizing literature from psychology, anthropology, and biology, I develop a novel hypothesis (Hominin Pathogen Control Hypothesis) to explain how these two distinct sets of behaviors evolved independently then merged in the human lineage. The hypothesis suggests that social care evolved in association with offspring care systems whereas community health behaviors evolved as a type of niche construction. These two types of behaviors merged in humans to produce complex, multi-level healthcare networks in humans. Moreover, each type of care increases selection for the other, generating feedback loops that selected for increasing healthcare behaviors over time. Interestingly, domestication processes may have contributed to both social care and community health aspects of this process.

A striking example of developmental bias in an evolutionary process: The "domestication syndrome"

The question of whether "developmental bias" can influence evolution is still controversial, despite much circumstantial evidence and a good theoretical argument. Here, I will argue that the domestication of mammalian species, which took place independently more than two dozen times, provides a particularly convincing example of developmental bias in evolution. The singular finding that underlies this claim is the repeated occurrence in domesticated mammals of a set of distinctive traits, none of which were deliberately selected. This phenomenon has been termed "the domestication syndrome". In this article, I will: (a) describe the properties of the domestication syndrome; (b) show how it can be explained in terms of the operation of a specific genetic regulatory network, that which governs neural crest cell development; and (c) discuss Dmitry Belyaev's idea of "destabilizing selection," which holds that selecting for a new behavior often entails neuroendocrine alterations that alter many aspects of development. Finally, I will argue for the potential general significance of such destabilizing selection, in combination with developmental bias, in animal evolution.

A natural adaptive syndrome as a model for the origins of cereal agriculture

A novel explanation of the origin of cereal agriculture is proposed, based on the ecology and adaptive morphology of wild cereals ancestral to our founder cereals (einkorn, emmer and barley). Wild cereals are unusually large-seeded. A natural evolutionary-ecological syndrome relates large seed, awns and monodominance (LAM). Awns bury attached seeds in the soil, protecting seed from fire; buried seed needs to be large to emerge on germination; large seeds, growing without competition from small-seeded plants, will produce monodominant vegetation. Climatic and edaphic instability at the Pleistocene-Holocene boundary would have provided an impetus for the spread of annual ruderal grasses. LAM grassland provided an obvious natural model for the origins of cereal agriculture. Subsequent field management would mimic the natural niche (MNN). The fact that monodominance is a long-standing character of the natural LAM syndrome validates cereal monocultures (now producing most of our food). An alternative explanation of crop domestication, by auditioning a great range of species for a human-constructed niche (NCT), is rejected.

Inferring the Origin of Cultivated Zizania latifolia, an Aquatic Vegetable of a Plant-Fungus Complex in the Yangtze River Basin

Crop domestication is one of the essential topics in evolutionary biology. Cultivated Zizania latifolia, domesticated as the special form of a plant-fungus (the host Zizania latifolia and the endophyte Ustilago esculenta) complex, is a popular aquatic vegetable endemic in East Asia. The rapid domestication of cultivated Z. latifolia can be traced in the historical literature but still need more evidence. This study focused on deciphering the genetic relationship between wild and cultivated Z. latifolia, as well as the corresponding parasitic U. esculenta. Twelve microsatellites markers were used to study the genetic variations of 32 wild populations and 135 landraces of Z. latifolia. Model simulations based on approximate Bayesian computation (ABC) were then performed to hierarchically infer the population history. We also analyzed the ITS sequences of the smut fungus U. esculenta to reveal its genetic structure. Our results indicated a significant genetic divergence between cultivated Z. latifolia and its wild ancestors. The wild Z. latifolia populations showed significant hierarchical genetic subdivisions, which may be attributed to the joint effect of isolation by distance and hydrological unconnectedness between watersheds. Cultivated Z. latifolia was supposedly domesticated once in the low reaches of the Yangtze River. The genetic structure of U. esculenta also indicated a single domestication event, and the genetic variations in this fungus might be associated with the diversification of cultivars. These findings provided molecular evidence in accordance with the historical literature that addressed the domestication of cultivated Z. latifolia involved adaptive evolution driven by artificial selection in both the plant and fungus.

Value of species and the evolution of conservation ethics

The theory of evolution by natural selection can help explain why people care about other species. Building upon recent insights that morality evolves to secure fitness advantages of cooperation, we propose that conservation ethics (moral beliefs, attitudes, intuitions and norms regarding other species) could be adaptations that support cooperation between humans and non-humans. We present eco-evolutionary cost-benefit models of conservation behaviours as interspecific cooperation (altruism towards members of other species). We find that an evolutionary rule identical in structure to Hamilton's rule (which explains altruistic behaviour towards related conspecifics) can explain altruistic behaviour towards members of other species. Natural selection will favour traits for selectively altering the success of members of other species (e.g. conserving them) in ways that maximize inclusive fitness return benefits. Conservation behaviours and the ethics that evolve to reinforce them will be sensitive to local ecological and socio-cultural conditions, so will assume different contours in different places. Difficulties accurately assessing costs and benefits provided by other species, time required to adapt to ecological and socio-cultural change and barriers to collective action could explain the apparent contradiction between the widespread existence of conservation ethics and patterns of biodiversity decline globally.

Ancient goat genomes reveal mosaic domestication in the Fertile Crescent

Current genetic data are equivocal as to whether goat domestication occurred multiple times or was a singular process. We generated genomic data from 83 ancient goats (51 with genome-wide coverage) from Paleolithic to Medieval contexts throughout the Near East. Our findings demonstrate that multiple divergent ancient wild goat sources were domesticated in a dispersed process that resulted in genetically and geographically distinct Neolithic goat populations, echoing contemporaneous human divergence across the region. These early goat populations contributed differently to modern goats in Asia, Africa, and Europe. We also detect early selection for pigmentation, stature, reproduction, milking, and response to dietary change, providing 8000-year-old evidence for human agency in molding genome variation within a partner species.