Motor inactivity in hibernating frogs: Linking plasticity that stabilizes neuronal function to behavior in the natural environment

All animals must generate reliable neuronal activity to produce adaptive behaviors in an ever‐changing environment. Neural systems are thought to achieve this goal, in part, through cellular and synaptic plasticity mechanisms that stabilize electrophysiological functions. Despite strong evidence for a role in regulating neuronal properties, these plasticity mechanisms have been difficult to link to natural behaviors in animals. In this review, I discuss how animals that inhabit extreme environments can address this challenge. As an example, I highlight recent work from frogs that stop breathing for several months during hibernation and, in response, use classic mechanisms of stabilizing plasticity to support respiratory motor output shortly after emergence. Furthermore, I describe problems for neuronal stability that may benefit from the study of hibernators: how circuits with variable modes of output control stabilizing mechanisms over long time scales and why some neural systems mount robust compensatory responses and others do not. By continuing to appreciate how diverse animal groups overcome challenges in the natural environment, we will broaden our view of the role that plasticity mechanisms play in stabilizing the nervous system.     

From Sender to Receiver: Propagation and Environmental Effects on Acoustic Signals

SYNOPSIS. Acoustic signals transmitted over large distancesdiffer significantly from those emitted by the signaler. Acousticsignals degrade in amplitude, spectral and temporal structureas they propagate through theenvironment. A great deal of workon acoustic communication is aimed at understanding the selectiveforces imposed by the environment on animal signals. I willdiscuss the physical constraints the environment puts on acousticcommunication, and then discuss similarities in communicationby anurans and insects that relate these environmental constraintsto their signaling systems. Lastly, I show how changes in signalsduring propagation relate to changes in signal perception duringphonotaxis, and thus, how propagation relates to mate choiceand sexual selection     

Fruit fly behavior in response to chemosensory signals

An important question in contemporary sensory neuroscience is how animals perceive their environment and make appropriate behavioral choices based on chemical perceptions. The fruit fly Drosophila melanogaster exhibits robust tastant and odor-evoked behaviors. Understanding how the gustatory and olfactory systems support the perception of these contact and volatile chemicals and translate them into appropriate attraction or avoidance behaviors has made an unprecedented contribution to our knowledge of the organization of chemosensory systems. In this review, I begin by describing the receptors and signaling mechanisms of the Drosophila gustatory and olfactory systems and then highlight their involvement in the control of simple and complex behaviors. The topics addressed include feeding behavior, learning and memory, navigation behavior, neuropeptide modulation of chemosensory behavior, and I conclude with a discussion of recent work that provides insight into pheromone signaling pathways.     

Parallel and divergent landscapes: cultural encounters in the ethnographic space of Tuareg medicine

This essay explores the dialogue between the local quest for healing and the anthropological quest for healing knowledge, and local assessments of knowledge-power relationships in these processes. The context is medical discourse among the Tuareg of Niger Republic, West Africa, and my research experiences among these people. I examine local medical specialists and their traditional and changing practice in terms of how they perceive and respond to wider knowledge and power systems that impinge on local health care. Paramount in these systems are central state policies and medical anthropological research on healing, as these intersect in a postcolonial and post-separatist/rebellion setting. The essay analyzes parallels between the exchange of medicine and the exchange of knowledge and reflects upon how anthropological knowledge of African healing systems is constructed in an environment highly charged with power and danger--of political violence and economic crisis. The broader issue addressed here is how to give greater empowerment to local residents' voices in their "indigenous critique" of the medical anthropological project.     

Virtual special issue: Social-ecological systems research in tropical ecosystems

Biodiversity is declining globally, primarily due to anthropogenic threats. Therefore, effective conservation efforts must integrate human and environmental components. Social-ecological systems research is increasingly being adopted as a means of studying complex relationships between people and the environment. I assess how researchers are employing social-ecological systems approaches or frameworks to the study of tropical ecosystems. I reviewed articles published in Biotropica from 2010 through 2022 searching for research on social-ecological systems. A broad keyword search revealed only 2 articles using a variation of social-ecological systems, human-environment systems, or coupled human and natural systems. This contrasts with a growing number of articles published with these search terms in other conservation-related journals, primarily led by environmental scientists. After reviewing titles for all 1298 research articles published during this period, I selected 12 articles for inclusion in the virtual special issue “Social-Ecological Systems Research in Topical Ecosystems”. These articles cover a broad range of geographical locations, ecosystem types, species, and conservation themes. Social-ecological systems frameworks offer an integrated way to study complex relationships between humans and nature, yet this type of research appears under-utilized by authors in Biotropica. I offer seven guidelines for authors interested in pursuing this research such as developing collaborations between social and environmental scientists.     

My past and a future role for inorganic biochemistry

The first part of this paper describes how my interest in bioinorganic chemistry was stimulated more than sixty years ago and how it has developed. The second part concerns a view of the future of the subject as an essential integral part of systems studies including organisms. After describing the essentials of any irreversible system, explaining how it is inevitably linked to its environment for material and energy, I analyse the roles of inorganic ions in this interactive unity to show the way the accidental oxidation of the environment by organisms has led to an inevitable progression of chemotypes in evolution. What is required in the future is detailed knowledge of the analytical content of the different compartmental structures of organisms, their division between free and bound forms, and the timing of their appearance. Historically this information needs to be related to both environmental and gene changes.     

In Defense of Some `Cartesian' Assumptions Concerning the Brain and Its Operation

I argue against a growing radical trend in current theoretical cognitive science that moves from the premises of embedded cognition, embodied cognition, dynamical systems theory and/or situated robotics to conclusions either to the effect that the mind is not in the brain or that cognition does not require representation, or both. I unearth the considerations at the foundation of this view: Haugeland's bandwidth-component argument to the effect that the brain is not a component in cognitive activity, and arguments inspired by dynamical systems theory and situated robotics to the effect that cognitive activity does not involve representations. Both of these strands depend not only on a shift of emphasis from higher cognitive functions to things like sensorimotor processes, but also depend on a certain understanding of how sensorimotor processes are implemented - as closed-loop control systems. I describe a much more sophisticated model of sensorimotor processing that is not only more powerful and robust than simple closed-loop control, but for which there is great evidence that it is implemented in the nervous system. The is the emulation theory of representation, according to which the brain constructs inner dynamical models, or emulators, of the body and environment which are used in parallel with the body and environment to enhance motor control and perception and to provide faster feedback during motor processes, and can be run off-line to produce imagery and evaluate sensorimotor counterfactuals. I then show that the emulation framework is immune to the radical arguments, and makes apparent why the brain is a component in the cognitive activity, and exactly what the representations are in sensorimotor control.     

结构稳定性: 概念、方法和应用

群落内物种间相互作用的结构是高度组织化的。群落结构对多物种共存的影响机制是群落生态学的核心科学问题之一。目前生态学界在这一问题上存在多种不同的观点。一个可能的原因是, 由于环境因子的复杂性, 大部分研究忽略了环境因子对群落结构和物种共存的重要影响。在这一背景下, 近期发展起来的结构稳定性理论系统地联系了群落结构、环境因子和物种共存, 并在此基础上建立了一个和经验数据紧密结合的理论框架。本文首先简要回顾了当前关于群落结构研究的争鸣, 然后介绍了结构稳定性的理论框架和计算方法, 最后详细介绍了结构稳定性理论在不同生态群落和不同生态学问题中的应用。在全球气候变化的背景下, 结构稳定性理论提供了一种新的视角来理解群落层面的生物多样性维持机制。     

Complex adaptive systems, aging and longevity.

Mortality and reproduction are intimately entwined in the study of aging and longevity. I apply the modern theory of complex adaptive systems (nonlinear, stochastic, dynamic methods) to questions of aging and longevity. I begin by highlighting major questions that must be answered in order to obtain a deeper understanding of aging. These are: (i) What should (in an evolutionary sense) mortality trajectories look like? (ii) Why does caloric restriction slow aging? (iii) Why does reproduction cause delayed mortality? (iv) Why does compensatory growth cause delayed mortality? I show how dynamic state variable models based on stochastic dynamic programming (Clark & Mangel, 2000) can be used to embed genetic theories of senescence (either mutation accumulation or antagonistic pleiotropy) in the somatic environment, as George Williams called for in 1957, and how they make the disposable soma theory of aging operational. Such models will allow unification of genetic and phenotypic theories of aging.     

The role of computation in modeling evolution

Artificial life uses computers and formal systems to model and explore the dynamics of evolution. A fundamental question for A-Life concerns the role of computation in these models, and how we are to interpret computer implementations that do not have actual contact with physical systems. In this paper I will discuss how models are seen to explain and predict in philosophy of science and how these ideas apply to A-Life. I will also explore how the notion of an epistemic cut, as defined by H. Pattee, can be realized in a computational model with an artificial physical world.     

Social eavesdropping and the evolution of conditional cooperation and cheating strategies

The response of bystanders to information available in their social environment can have a potent influence on the evolution of cooperation and signalling systems. In the presence of bystanders, individuals might be able to increase their payoff by exaggerating signals beyond their means (cheating) or investing to help others despite considerable costs. In doing so, animals can accrue immediate benefits by manipulating (or helping) individuals with whom they are currently interacting and delayed benefits by convincing bystanders that they are more fit or cooperative than perhaps is warranted. In this paper, I provide some illustrative examples of how bystanders could apply added positive selection pressure on both cooperative behaviour and dishonest signalling during courtship or conflict. I also discuss how the presence of bystanders might select for greater flexibility in behavioural strategies (e.g. conditional or condition dependence), which could maintain dishonesty at evolutionarily stable frequencies under some ecological conditions. By recognizing bystanders as a significant selection pressure, we might gain a more realistic approximation of what drives signalling and/or interaction dynamics in social animals.     

Settler indigeneity and the eradication of the non‐native: self‐determination and biosecurity in the Falkland Islands (Malvinas)

This article analyses how settlers of the Falkland Islands (Malvinas) construct themselves as ‘natives’ through environmental management. Taking a multispecies ethnographic and historical approach to studying the Falkland Islanders’ self‐determination claim, I explore a series of ecological practices that demonstrate how some nonhumans become institutionalized into systems of racial and colonial classification whereas others appear natural. I show how agroindustrial and technoscientific value systems categorize human and nonhuman cohabitants according to degrees of political, economic, and ecological status through particular periods in the Falklands: from the eradication of ‘native pests’ (1833‐1982) to defence against ‘alien invaders’ (1982‐present). Towards a conclusion, I analyse how Islanders have begun to uproot their own ecological imperial past through removal of British‐introduced ‘invasive’ species and native habitat restoration. The article argues that attention to how settlers colonize with natives contributes significantly to a critical multispecies anthropology with broader implications for debates on ethnogenesis and indigeneity.     

The combined role of the main olfactory and vomeronasal systems in social communication in mammals

The main olfactory and the vomeronasal systems are the two systems by which most vertebrates detect chemosensory cues that mediate social behavior. Much research has focused on how one system or the other is critical for particular behaviors. This has lead to a vision of two distinct and complexly autonomous olfactory systems. A closer look at research over the past 30 years reveals a different picture however. These two seemingly distinct systems are much more integrated than previously thought. One novel set of chemosensory cues in particular (MHC Class I peptide ligands) can show us how both systems are capable of detecting the same chemosensory cues, through different mechanisms yet provide the same general information (genetic individuality). Future research will need to now focus on how two seemingly distinct chemosensory systems together detect pheromones and mediate social behaviors. Do these systems work independently, synergistically or competitively in communicating between individuals of the same species?     

细菌分泌系统的结构及作用机制研究进展

细菌分泌系统（bacterial secretion systems）是一类存在于细菌细胞膜上的大分子复合物，是结构复杂的跨膜分子机器，可为多种细菌的效应物提供分泌途径。目前已经发现了9种细菌分泌系统，即T1SS~T9SS，在细菌的生存及致病力方面发挥着重要作用。随着X射线晶体学（X-ray crystallography）、核磁共振（nuclear magnetic resonance，NMR）及冷冻电镜（cryo-electron microscopy，Cryo-EM）等技术手段的发展与应用，这些大分子复合物的三维结构也得到了一定程度的解析，极大增强了人类对于细菌分泌系统转运底物复杂机制的理解。因此，本文结合近年来关于细菌T1SS~T9SS的研究进展，对各分泌系统的结构信息进行了系统整合，总结了这些分泌系统的分子作用机制，并对其未来的发展方向进行了展望，以期为与细菌蛋白质分泌相关的致病、耐药、环境适应性等机制的研究奠定理论基础，为进一步开发以分泌系统结构为基础的小分子抑菌物质提供精准的三维靶标。     

Functional blueprints: an approach to modularity in grown systems

The engineering of grown systems poses fundamentally different system integration challenges than ordinary engineering of static designs. On the one hand, a grown system must be capable of surviving not only in its final form, but at every intermediate stage, despite the fact that its subsystems may grow unevenly or be subject to different scaling laws. On the other hand, the ability to grow offers much greater potential for adaptation, either to changes in the environment or to internal stresses developed as the system grows. I observe that the ability of subsystems to tolerate stress can be used to transform incremental adaptation into the dynamic discovery of viable growth trajectories for the system as a whole. Using this observation, I propose an engineering approach based on functional blueprints, under which a system is specified in terms of desired performance and means of incrementally correcting deficiencies. I explore how manifold geometric programming can support such an approach by simplifying the construction of distortion-tolerant programs, then demonstrate the functional blueprints approach by applying it to integrate simplified models of tissue growth and vascularization, and further show how the composed system may itself be modulated for use as a component in a more complex design.     

Functional genomics of neural and behavioral plasticity

How does the environment, particularly the social environment, influence brain and behavior and what are the underlying physiologic, molecular, and genetic mechanisms? Adaptations of brain and behavior to changes in the social or physical environment are common in the animal world, either as short-term (i.e., modulatory) or as long-term modifications (e.g., via gene expression changes) in behavioral or physiologic properties. The study of the mechanisms and constraints underlying these dynamic changes requires model systems that offer plastic phenotypes as well as a sufficient level of quantifiable behavioral complexity while being accessible at the physiological and molecular level. In this article, I explore how the new field of functional genomics can contribute to an understanding of the complex relationship between genome and environment that results in highly plastic phenotypes. This approach will lead to the discovery of genes under environmental control and provide the basis for the study of the interrelationship between an individual's gene expression profile and its social phenotype in a given environmental context.     

Molecular and cellular organization of insect chemosensory neurons

Animals use their chemosensory systems to detect and discriminate among chemical cues in the environment. Remarkable progress has recently been made in our knowledge of the molecular and cellular basis of chemosensory perception in insects, based largely on studies in Drosophila. This progress has been possible due to the identification of gene families for olfactory and gustatory receptors, the use of electro-physiological recording techniques on sensory neurons, the multitude of genetic manipulations that are available in this species, and insights from several insect model systems. Recent studies show that the superfamily of chemoreceptor proteins represent the essential elements in chemosensory coding, endowing chemosensory neurons with their abilities to respond to specific sets of odorants, tastants or pheromones. Investigating how insects detect chemicals in their environment can show us how receptor protein structures relate to ligand binding, how nervous systems process complex information, and how chemosensory systems and genes evolve.     

The combined role of the main olfactory and vomeronasal systems in social communication in mammals

The main olfactory and the vomeronasal systems are the two systems by which most vertebrates detect chemosensory cues that mediate social behavior. Much research has focused on how one system or the other is critical for particular behaviors. This has lead to a vision of two distinct and complexly autonomous olfactory systems. A closer look at research over the past 30 years reveals a different picture however. These two seemingly distinct systems are much more integrated than previously thought. One novel set of chemosensory cues in particular (MHC Class I peptide ligands) can show us how both systems are capable of detecting the same chemosensory cues, through different mechanisms yet provide the same general information (genetic individuality). Future research will need to now focus on how two seemingly distinct chemosensory systems together detect pheromones and mediate social behaviors. Do these systems work independently, synergistically or competitively in communicating between individuals of the same species?     

Life on the hoof: gender,youth, and the environment in the Indian Himalayas

This article examines how young people in the Indian Himalayas understand, appreciate, and discuss their environment. Building on intensive ethnographic field research in Bemni, Uttarakhand, I point to the changing ways in which young people use the everyday practice of herding to acquire knowledge and engage in playful activity. I emphasize that age and gender shape the capacity for young people to interact creatively with their local environments. I will argue that studies of human/environment relations might usefully combine a focus on the movement of individuals through environments with a focus on the gendered ways in which they move through the life‐course.     

Moments of Hierarchy: Constructing Social Stratification by Means of Language, Food, Space, and the Body in Pohnpei, Micronesia

In this paper I examine relationships between multiple semiotic modes used to construct hierarchy, and I show the importance of going beyond our traditional notion of language to look at how social actors employ a range of semiotic resources in organizing and interpreting social relations. Using examples from Pohnpei, Micronesia, I show how notions of superior and inferior are compounded through several sign systems—spatial relations, food sharing, the body, and language. These systems act oppositionally as well as cooperatively to produce situated ideas of social inequality, ideas built out of disequilibrium of bodies in space, of referents in language, and distribution of resources, as well as contradictions in the interactions of these signs. The compounding of signs not only recruits multiple sensory modes and perspectives in the exposition of hierarchical relations, but entails a notion of the contradictory nature of status relations. Using examples from a Pohnpeian feast, I explore the creative interplay of sign systems in the construction of "moments" of hierarchy in a large, public setting and discuss how through the practice of title-giving, which virtually every adult member of the society participates in, a particular idea of social inequality, built out of multiple sign systems, is mapped onto each body, [language, interaction, politics, Oceania, social stratification, hierarchy]