System-Dependent Selection, Ecological Feedback, and the Emergence of Functional Structure in Ecosystems

ArticleinJournal of Theoretical Biology 192(98-01-014) · June 1998with 173 Reads
DOI: 10.1006/jtbi.1998.0664 · Source: RePEc
Abstract
The growth of young, technology-based firms has received considerable attention in the literature given their importance for the generation and creation of economic wealth. Taking a strategic management perspective, we link the entrepreneurial strategy deployed by young, technology-based firms with firm growth. In line with recent research, we consider both revenue and employment growth as they reflect different underlying value creation processes. Using a unique European dataset of research-based spin-offs, we find that firms emphasizing a product and hybrid strategy are positively associated with growth in revenues. The latter strategy also has a positive influence on the creation of additional employment. Contrary to expectation, however, we find that firms pursuing a technology strategy do not grow fast in employment. Our study sheds new light on the relationship between entrepreneurial strategy and firm growth in revenues and employment.

Do you want to read the rest of this article?

Request full-text
Request Full-text Paper PDF
  • ... One way in which dynamic elements may be introduced in environmental carrying capacities is by positing a feedback connection between population density and resource constraints. Following recent work in theoretical biology, we call the evolutionary regime determined by the presence of feedback loops between populations and their resources "system dependent selection" ( Lansing et al. 1998, Lovelock 1992, Wilson and Agnew 1992. Once dynamic con siderations are introduced in environmental carry ing capacities, a substantive theoretical and empirical problem involves the development of a coherent set of assumptions about the speed at which organizational populations can adjust to changing environments or, in other words, about population-level inertia. ...
    ... Conventional ecological models assume that the material environment constrains population growth rates, but that populations do not influence their material environment. When this assumption does not hold, the feedback connection between the pop ulation and its resources becomes itself part of a more general coevolutionary process ( Lansing et al. 1998). Theoretical biologists call this evolutionary regime "system-dependent selection" because, unlike density-dependent selection, vital rates (and therefore diversity) depend on the feedback connection exist ing between populations and their resources ( Lansing et al. 1998, Lovelock 1992, Wilson and Agnew 1992. ...
    ... When this assumption does not hold, the feedback connection between the pop ulation and its resources becomes itself part of a more general coevolutionary process ( Lansing et al. 1998). Theoretical biologists call this evolutionary regime "system-dependent selection" because, unlike density-dependent selection, vital rates (and therefore diversity) depend on the feedback connection exist ing between populations and their resources ( Lansing et al. 1998, Lovelock 1992, Wilson and Agnew 1992. When the evolution of organizational populations is driven by system-dependent selection, the essential theoretical and empirical problems are less related to the form of time dependence in the effect of density on vital rates, and more to the form of the causal feedback mechanisms between populations and their environments. ...
  • ... We can call this the central planning hypothesis. CliffordGeertz (1981), followed by Lansing and his colleagues (Lansing, 2006, 2007[1991];Lansing et al., 2009;Lansing & Kremer, 1993), 8 argued that the Balinese 6 The material in this section is based primarily on (C.Geertz, 1981;Janssen, 2007;Lansing, 2006, 2007[1991];Lansing, Cox, Downey, Jannsen, & Schoenfelder, 2009;Lansing & de Vet, 2012;Lansing & Kremer, 1993;Lansing, Kremer, & Smuts, 1998Lansing & Fox, 2011;Lansing et al., 1998).Lansing & Kremer, 1993need to confer with other subaks across an entire watershed in order to produce the kind of pattern of coordination that is observed. Evidence produced in support of the central planning and distributed decisions hypotheses has come from historical documents, interviews, surveys, ethnographic work, and archaeological data. ...
    ... We can call this the central planning hypothesis. CliffordGeertz (1981), followed by Lansing and his colleagues (Lansing, 2006, 2007[1991];Lansing et al., 2009;Lansing & Kremer, 1993), 8 argued that the Balinese 6 The material in this section is based primarily on (C.Geertz, 1981;Janssen, 2007;Lansing, 2006, 2007[1991];Lansing, Cox, Downey, Jannsen, & Schoenfelder, 2009;Lansing & de Vet, 2012;Lansing & Kremer, 1993;Lansing, Kremer, & Smuts, 1998Lansing & Fox, 2011;Lansing et al., 1998).Lansing & Kremer, 1993need to confer with other subaks across an entire watershed in order to produce the kind of pattern of coordination that is observed. Evidence produced in support of the central planning and distributed decisions hypotheses has come from historical documents, interviews, surveys, ethnographic work, and archaeological data. ...
    Chapter
    Full-text available
    Culture often seems to exhibit a high degree of harmony or coherence, exhibiting various sorts of "fit" between cultural patterns in disparate domains. In this paper, I explore one strategy for explaining some kinds of cultural coherence. I show how a gradual process by which individuals with different cultural variants influence each other could lead to such coherence. More specifically, I use computer simulations to model the spread of religious patterns specific to rice growing regions in southern Bali. These are cultural patterns that exhibit a high degree of of coherence with Balinese beliefs about the natural world. I show that the religious patterns could have spread through cultural transmission biased by variation in harvest success, under the influence of local social and ecological conditions. The simulations also highlight the potential importance of what we might call "population communication structure" in cultural transmission: In the simulations, spread of certain religious cultural patterns was likely only when communication from distant farming regions occurred infrequently. This communication pattern allowed homogeneity in small regions to develop, creating pragmatic benefits that subsequently made religious practices in those regions attractive to individuals in other areas. This ability of partial isolation to preserve variation and to support group-beneficial effects is well known from evolutionary biology. There has previously been a great deal of research on group-level effects in cultural transmission as well as on effects of communication structure on cultural transmission. There are other proposals according to which group-level effects have played an important role in the spread of certain religious practices The present research, however, illustrates a new way that explanations of harmonious cross-domain cultural patterns may be constrained by effects of communication structure.
  • ... Gunderson 1999, Folke et al. 2003, Olsson 2003). For example, networks of socially interconnected water temples (centers of local farmers) can suppress pest outbreaks in an water-limited irrigated agriculture system by facilitating coordinated harvesting activities (Lansing et al. 1998). Furthermore, it has been argued that knowledge of the complex patterns of interactions between and among various subgroups in communities is crucial in studying co-management (described further on) of natural resources (Carlsson and Berkes 2005). ...
    ... This argument is further strengthened by the numerous studies that have shown that the existence of informal social networks among, and between, various stakeholders and groups is very important in successful cases of bottom-up community-based natural resource management (e.g.Gunderson 1999, Olsson 2003). For example, networks of socially interconnected water temples (centers of local farmers) can suppress pest outbreaks in an water-limited irrigated agriculture system by facilitating coordinated harvesting activities (Lansing et al. 1998). Furthermore, it has been argued that knowledge of the complex patterns of interactions between and among various subgroups in communities is crucial in studying co-management (described further on) of natural resources (Carlsson and Berkes 2005). ...
  • ... An example taken from a wet-rice farming region on the Indonesian island of Bali provides evidence that it is achievable, albeit even if arrived at serendipitously. In this 97,337 hectare region, farmers must synchronize their planting and irrigation schedules by subregion to ensure the adequate availability of water resources (Lansing et al. 1998). The synchronized planting schedules also function to suppress the growth and dispersal of rice pests including rats, insects and insect-vectored plant diseases (Aryawan et al. 1993). ...
    ... The synchronized planting schedules also function to suppress the growth and dispersal of rice pests including rats, insects and insect-vectored plant diseases (Aryawan et al. 1993). Over time, the mutually compatible goals of crop production and pest management facilitated the functional system dependent selection and ecological feedback regulation of pest outbreaks within the region (Lansing et al. 1998). ...
  • ... In this model, daisies modify their local temperature and thus self-regulate the global temperature (Lovelock, 1992; Watson and Lovelock, 1983 ). If error-prone selfreplication is assumed, then an evolutionary process takes place in a Daisyworld within a changing environment (Lansing et al., 1998; McDonald-Gibson et al., 2008). This is the complete dynamical system we consider in this paper. ...
    ... In this paper we have analyzed a dynamic model in which errorprone self-replicative species (replicators) interact with their environment . The model follows previous approaches by Lansing et al. (1998) and McDonald-Gibson et al. (2008) and can be understood as an extension of both the Daisyworld of Watson and Lovelock 10 jdH* shows the time evolution of public opinion (dashed) and the average fitness (solid), whereas (b) depicts the time evolution of the total population. A quasispecies is formed around T= —40, with all the species having a «-value equal to —0.02636, although the average fitness is not optimal (around 8 over 10.). ...
    Article
    This paper presents a model of a population of error-prone self-replicative species (replicators) that interact with its environment. The population evolves by natural selection in an environment whose change is caused by the evolutionary process itself. For simplicity, the environment is described by a single scalar factor, i.e. its temperature. The formal formulation of the model extends two basic models of Ecology and Evolutionary Biology, namely, Daisyworld and Quasispecies models. It is also assumed that the environment can also change due to external perturbations that are summed up as an external noise. Unlike previous models, the population size self-regulates, so no ad hoc population constraints are involved. When species replication is error-free, i.e. without mutation, the system dynamics can be described by an (n + 1)-dimensional system of differential equations, one for each of the species initially present in the system, and another for the evolution of the environment temperature. Analytical results can be obtained straightforwardly in low-dimensional cases. In these examples, we show the stabilizing effect of thermal white noise on the system behavior. The error-prone self-replication, i.e. with mutation, is studied computationally. We assume that species can mutate two independent parameters: its optimal growth temperature and its influence on the environment temperature. For different mutation rates the system exhibits a large variety of behaviors. In particular, we show that a quasispecies distribution with an internal sub-distribution appears, facilitating species adaptation to new environments. Finally, this ecologically inspired evolutionary model is applied to study the origin and evolution of public opinion.
  • ... In this way, the pyric phases emphasize nonlinearities and key entanglements among human popula- tions, technologies, economies and pyroge- ographies, even as change is not assumed to be unidirectional. Although our adapta- tion is conceptual rather than quantitative, the complex adaptive system analysis of social and ecological systems with multiple basins of attraction is an emerging area of interest for anthropologists and other social scientists ( Lansing et al., 1998;Lansing, 2003;Lansing & Downey, 2011). ...
    ... Additional important sources for theory and testable hypotheses include ecosystem ecology and complex adaptive systems theory ( Lansing et al., 1998;Holling, 2001;Beisner et al., 2003;Lansing, 2003;Scheffer & Carpenter, 2003). Empirical and simula- tion studies are beginning to identify nonlinearities and novel dynamics in human-fire relationships (e.g. ...
    Article
    Full-text available
    In our 2011 synthesis (Bowman et al., Journal of Biogeography, 2011, 38, 2223–2236), we argued for a holistic approach to human issues in fire science that we term 'pyrogeography'. Coughlan & Petty (Journal of Biogeography, 2013, 40, 1010–1012) critiqued our paper on the grounds that our 'pyric phase' model was built on outdated views of cultural development, claiming we developed it to be the unifying explanatory framework for all human–fire sciences. Rather, they suggest that 'historical ecology' could provide such a frame-work. We used the 'pyric transition' for multiple purposes but did not offer it as an exclusive explanatory framework for pyrogeography. Although 'historical ecology' is one of many useful approaches to studying human–fire relationships, scholars should also look to political and evolutionary ecology, ecosystems and complexity theories, as well as empirical generalizations to build an interdisciplinary fire science that incorporates human, ecological and biophysical dimensions of fire regimes.
  • ... e fitness of genotypes that were maximally fit before, it may increase the fitness of other genotypes present in the population. That is, environmental change engendered by one genotype (or population or species) may well benefit a second genotype. This, of course, is just what happens among species during ecological succession (e.g. Lenton, 1998). Lansing et al. (1998) termed this response 'system-dependent' selection and argued that it will increase environmental regulation by the biota. I suspect that in the presence of biological variation, population genetics will commonly act as a buffer against biologically induced environmental change, but the buffer is weak and I have no confidence it will hol ...
    ... Robertson & Robinson (1998) modelled a Daisyworld in which evolving daisies shifted their optimal growth temperature to match their local environment . In consequence, the bioregulation observed in purely ecological models broke down (see also Lansing et al., 1998). Such simulations suggest that, by itself, system-dependent selection will not predictably endow ecosystems with negative feedbacks. ...
    Article
    Geobiologists seek to understand the role of organisms in the Earth system. By extension, one can ask how evolutionary innovations and, more generally, the population genetic processes that mediate evolution have influenced the Earth’s surface through time. The example of oxygenic photosynthesis and the redox history of atmospheres and oceans illustrates the complex relationship between evolution and environmental change. Biological innovations determine the dimensions of biological participation in the Earth system, but by themselves they seldom generate lasting environmental change. More commonly, environments change when physical drivers exceed the limited environmental buffering capacity conferred by population genetics and nutritional codependence. Environmental change, in turn, feeds back on biology, creating new opportunities for evolutionary innovation. Organismic and Evolutionary Biology
  • ... For example , the flocking behavior of birds looks random and disorganized but can be modeled with three rules ( Waldrop 1992 , 241 – 43 ) . The location of water temples in Bali can be simulated with a few rules of kinship and farming practice ( Lansing , Kre - mer , and Smuts 1998 ) . The collapse of the Anasazi civilization in the American Southwest has been explained by the interaction of social rules and environ - mental changes ( Axtell et al . ...
    Article
    Full-text available
    Despite nearly a hundred years of theorizing, scholars and practitioners alike are constantly surprised by international and global political events. The abrupt end of the much-studied Cold War was widely unanticipated, as were the conse- quences of the collapse of communism in Europe. The defining characteristics of four decades of international politics were erased in a few short years, but the globalization of economic and social life has continued. The 1997 Asian finance crisis rattled the US and European stock markets, civic strife in Venezuela influ- ences the price of oil, and the needs of AIDS patients in South Africa challenge international agreements on intellectual property. Out of the blue, terrorists at- tacked within the United States one sunny September morning. A year earlier, in the space of a few months the global economy lurched from rapid expansion to recession and flirted with deflation. After so much ink has been spilt, we still know so little about international relations and world politics that events continue to surprise us. There is no agree- ment on the cause of this failure. Some believe that international theorists think too small and fail to synthesize relevant insights from a range of disciplines (Buzan and Little 2001); others criticize the emphasis on positivist methods (Smith, Booth, and Zalewski 1996); and postmodern scholars reject the ahistorical, ratio- nalist foundations of most international theory (Der Derian and Shapiro 1989; George and Campbell 1990). This book takes a different tack. It argues that the reality of world politics is more complex than dreamt of in current theories. Current theories of world politics assume that the social world is appro- priately modeled as a simple system; this book proposes that it should instead be viewed as a complex system. In this book my colleagues and I describe, and demonstrate the benefits of, a paradigm of system emergence from complex
  • ... This diverts our attention away from the real phenomenon of interest, the role of the flowers in planetary engineering. A full understanding of coevolution on Daisyworld requires a coevolutionary model, such as niche construction , which goes beyond variation in individual fitness to analyze the effects of environmental coupling at the population level (Lansing, Kremer, and Smuts 1998). How important is this distinction? ...
    Article
    Full-text available
    Do cultural phenomena undergo evolutionary change, in a Darwinian sense? If so, is evolutionary game theory (EGT) the best way to study them? Opinion on these questions is sharply divided. Proponents of EGT argue that it offers a unified theoretical framework for the social sciences, while critics even deny that Darwinian models are appropriately applied to culture. To evaluate these claims, we examine three facets of cultural evolution: (i) cultural traits that evolve by Darwinian selection, (ii) cultural traits that affect biological fitness, and (iii) coevolution of culture and biology, where selection in one affects evolutionary outcomes in the other. For each of these cases, the relevance of EGT depends on whether its assumptions are met. Those assumptions are quite restrictive: selection is constant, time horizons are deep, the external environment is not part of the game, and neutral processes such as drift are irrelevant. If these conditions are not met, other evolutionary models such as neutrality, coalescence theory, or niche construction may prove more appropriate. We conclude that Darwinian processes can occur in all three types of cultural or biological change. However, exclusive reliance on EGT can obscure the respective roles of selective and neutral processes.
  • ... Another test of our theoretical ideas relies on the computational model of Lansing and Kremer (1993 Kremer ( , 1998) In the artificial experiment we find that as cooperation spreads, harvests tend to even out across the subaks. As cooperation emerges in the model, everyone obtains nearly identical yields, which average out to be better than any of the yields obtained prior to cooperation. ...
    Article
    Full-text available
    For centuries Balinese rice farmers have been engaged in cooperative agricultural practices. Without centralized control, farmers have created a carefully coordinated system that allows productive farming in an ecosys- tem that is rife with water scarcity and the threat of disease and pests. We develop a simple game-theoretic model, inspired by a generation of careful anthropological eld work, to provide a compact explanation for many of the most salient features observed in the system. We nd that
  • ... Balinese water temple networks show that complex patterns of cooperation can emerge and persist as a result of feedback in a coupled human-natural system (Lansing et al. 1998). In our budding model, local initiatives and demographic events, rather than elite sponsorship, power the creation of a landscape of complex physical irrigation systems and an equally complex hierarchy of flexible common-pool resource managerial institutions. ...
    Article
    Full-text available
    Ethnohistory, genetics and simulation are used to propose a new 'budding model' to describe the historical processes by which complex irrigation communities may come into existence. We review two alternative theories, Wittfogel's top-down state-formation theory and common-pool resource management, and suggest that a budding model would better account for existing archaeological and ethnographic descriptions of a well-studied network of irrigation communities on the island of Bali. The budding model is supported by inscriptions and ethnohistorical documents describing irrigation works in and around the drainage of the Petanu River, an area with some of the oldest evidence for wet-rice agriculture in Bali. Genetic analysis of Y-STR and mtDNA shows correlated demographic histories and decreased diversity in daughter villages, consistent with the budding model. Simulation results show that the network of irrigation communities can effectively adjust to repeated budding events that could potentially shock the system outside the parameter space where good harvests can be maintained. Based on this evidence we argue that the budding model is a robust explanation of the historical processes that led to the emergence and operation of Petanu irrigation communities.
  • ... The Daisyworld model offers insight into the emergence of a complex adaptive system based on the role of water temples in managing wet-rice cultivation on the Indonesian island of Bali [Lansing et al., 1998]. In Bali, rice is grown in paddy fields on steep hillsides fed by elaborate irrigation systems dependent on seasonal rivers and ground water flows, dominated by an elevated volcanic crater lake. ...
    Chapter
    This chapter discusses the application of "complexity" into anthropology studies. By tracing patterns of interaction among the elements of a system, one can sometimes discover emergent properties at a higher level. This phenomenon is common to all of the examples, from semiotics to agency, innovation, cultural evolution and human-environmental interactions. But, until recently, mathematical tools were not well suited to investigate emergence, or other properties of out-of-equilibrium dynamical systems. Recently, it has been argued that social scientists who wish to take advantage of mathematics have the choice of only two approached. The first is essentially Newtonian and is best represented by general equilibrium theories, for example in economics. Such theories take the form of systems of differential equations describing the behavior of simple homogeneous social actors. Change occurs as a result of perturbations and merely leads from one equilibrium state to another. The second type of theory is statistical. If one cannot write the equations to define a dynamical system, it may yet be possible to observe statistical regularities in social phenomena. Both approaches have obvious weaknesses: the assumption of equilibrium is forced by the mathematics, not by the observation of social behavior, and sifting for patterns with descriptive statistics is at best an indirect method for discovering causal or developmental relationships. The landscape looks very different today. Out-of-equilibrium systems are the main topic of complexity research, and there has been a proliferation of new analytical methods to investigate them. Of particular interest to anthropologists are the models of "artificial societies", of which the "Bali Model" is an example. Artificial societies are computational models comprising populations of social agents that flourish in artificial environments.
  • ... Another test of our theoretical ideas relies on the computational model of Lansing and Kremer (1993 Kremer ( , 1998). This model captures major hydrological and biological features of 172 subaks relying on the Oos and Petanu rivers in the region of Gianyar. ...
    Article
    Full-text available
    For centuries Balinese rice farmers have been engaged in cooperative agricultural practices. Without centralized control, farmers have created a carefully coordinated system that allows productive farming in an ecosys-tem that is rife with water scarcity and the threat of disease and pests. We develop a simple game-theoretic model, inspired by a generation of careful anthropological field work, to provide a compact explanation for many of the most salient features observed in the system. We find that while externalities caused by either water scarcity or pests would, in iso-lation, be expected to cause a serious failure in the system, the ecology of the rice farming system links these two externalities in such a way that cooperation, rather than chaos, results. We test key features of the model through both natural and computational experiments and a field survey focused on the strategic motivations of the farmers.
  • ... Recently, the efforts to reconcile Gaia with Darwinism have intensified (e.g. Levine 1993, Tickell 1993, Lovelock and Kump 1994, Saunders 1994, Markos 1995, Stö cker 1995, Harding and Lovelock 1996, Benci and Galleni 1998, Hamilton and Lenton 1998, Lansing et al. 1998, Lenton 1998, Levin 1998, Robertson and Robinson 1998, Downing and Zvirinsky 1999, Lenton and Lovelock 2000. In this journal, Wilkinson (1999) asked ''Is Gaia really conventional ecology?'', and answered positively. ...
    Article
    In this forum, David M. Wilkinson argued that Gaia-type phenomena can be explained by conventional ecological ideas meaning that such phenomena do not require major changes to existing ecological or evolutionary theory. Overstating my case a little, I will argue that a reconciliation between Gaia and Darwinism will not be conventional in the sense of mainstream ecology. The main addition of this essay is an exploration in how far the claim that the atmosphere is an extension of life on Earth is logically correct. In a thought experiment, the idea of extended phenotypes by Richard Dawkins can be integrated with the one of Gaia. The problem of cheats remains pertinent, however, because the atmosphere will not select differentially between cheats and non-cheats. Conclusion: Gaia-type phenomena will be by-products of naturally selected traits. As such they are not jeopardised by cheats, because side effects can be free to self-organise, while the main effects will be naturally selected for evolutionarily stable states. Understanding the laws of self-organisation of such side effects will be of major importance to all environmental sciences.
  • ... This includes scientific Gaia research, and some of the best examples come from Lovelock's many Daisyworld simulations (Watson and Lovelock 1983). Anthropologist Stephen Lansing has joined this research with system-dependent selection (Lansing, et al. 1998 ). Lansing and coauthors model evolutionary dynamics in Bali when ecological feedback between organisms and environment is included in the evolutionary process. ...
    Article
    Full-text available
    Darwin's theory of evolution follows from a few simple ideas. Our physiology and behavior are the result of variation, selection, and transmission over recursive bouts of reproduction. It is thought that scientific anthropology should therefore look for the ultimate causes of behavior in this core of ideas, with explanation of even the most complex behaviors extending outward from it. But another equally fundamental scientific theory of causality exists—and in some way rivals or subsumes Darwin's theory. The behavior of energy in open systems is understood with an equal simplicity and clarity. A concentration of energy in any form will spontaneously dissipate to equilibrium. If the nonequilibrium concentration is great enough, the dissipation can take on fantastic forms of 'self-organized' structure, which arguably include life, the formation of ecosystems, and the behavior of all parts within. Perhaps scientific anthropology should also look here for ultimate causes of human behavior. There's a difference between the two that is frequently indicated. Evolution in its present form is practiced with precise measure leading to prediction on modest scales of space and time. The theory of self- organization in complex systems, on the other hand, takes direct aim at the immodest complexity of nature and life, seeking general understanding. Some reserve the label science for the first with its targeted design and experimental disproof. But arguably science occurs in two streams, one analytical and one integrative, as the ecologist Holling (1998) has said. Anthropology's promise may better come clean in the second stream. Function, Causality and Evolution Consider for a moment Elster's (1983) familiar three modes of explanation, featured prominently in Winterhalder and Smith (1992:42). The causal mode relies on material properties from physics and chemistry, such as gravity, or chemical reaction gradients. The functional mode explains events by their unintended beneficial consequences. An intentional explanation, as we would expect, locates causality in the intentions of actors. According to Elster, the functional and intentional modes are always incomplete, unless they can be shown to rest ultimately on causal explanations.
  • ... Also not clear evidence of this is what Lansing and de Vet cite on the efficacy of synchronized fallowing for controlling pests. 2 If the temple-associated synchronization of irrigation schedules did indeed help to keep down pest populations prior to the Green Revolution, this would not necessarily mean that farmers were " knowingly " attempting to control pests by means of their temple-associated cropping system (cf. Lansing et al. 1998: 382 on the system as the outcome of a selective process driven only by pestcontrol and water-management needs). Pest control could have been a by-product of the development of the system for other reasons. ...
    Article
    Full-text available
    Historical, ecological, and methodological arguments are presented against the claims of antiquity that are made by J. S. Lansing and his associates for the evolution of the role of networks of water temples not only in the allocation of irrigation water but also in the control of rice-field pests over entire watersheds on the island of Bali in Indonesia.
  • ... This mismatch is a hint that the wrong modeling paradigm might be being used. Where these systems are studied and simulated today in ecosystem research, the ultimate goal is to replace the heuristics of management with a process-based understanding of the dynamics (Lansing et al. 1998 ). Here, scientific knowledge in considered to be, in principle, superior to any other form of knowledge. ...
  • ... It is sometimes assumed that SK can serve as the ontological comparator, or the 'metalanguage in terms of which the folk system can he understood' (Berlin 1992: 201). Some behaviour is seen as influenced by group dynamics at a level at which Farmers may not he cognizant, for example in the management of large-scale irrigation systems ( Lansing et al. 1998). ...
  • ... the biotic relations of pests in the main food crops. Snakes and the few remaining leopard cats and civets in the still forested landscape are recognised for keeping rat populations under control. In years that the bamboo flowers and sets fruit rats and mice rapidly multiply and the following cropping season rice crops may fail, leading to famine. Lansing et al. (1998) analysed the water temple system in Bali that integrates spatial patterns of rice cultivation in relation to the lateral flows of irrigation water and of pests. Thapa et al. (1995) described a rigorous methodology that is available for further analysis of such local knowledge systems that include lateral flows. To achieve 'integrated na ...
  • ... staggered cropping schedules for entire watersheds . . . the actual patterns [we] have observed in the field bear a very close resemblance to computer simulations of optimal solutions " (Lansing 2000, p. 313). In subsequent experiments, we pursued the kinds of questions Kauffman posed in The Origins of Order, such as the relationship between the structure of connections between farming communities (subaks) and the ability of the entire collection of subaks to self-organize (Lansing et al. 1998). In the Balinese case, global control of terrace ecology emerges as local actors strike a balance between two opposing constraints: water stress from inadequate irrigation flow and damage from rice pests such as rats and insects. ...
  • ... Dong (2008) developed a conceptual model, describing the structure and function of river ecosystem. The assessment of river ecosystem was studied earlier abroad, and more research concentrated on a biological commu- nity via its features, changes and the feedback mechanisms to reflect the health of river ecosystem (National Research Council, 1992;Lansing et al., 1998;Lakly and McArthur, 2000; Bain et al., 2000;Gallardo et al., 2011;Ramos et al., 2012). There are a great amount of evaluation methods including fuzzy method, grey sys- tem theory, matter element analysis method, principal component analysis. ...
  • ... Another test of our theoretical ideas relies on the computational model of Lansing and Kremer (1993 Kremer ( , 1998) In the artificial experiment we find that as cooperation spreads, harvests tend to even out across the subaks. As cooperation emerges in the model, everyone obtains nearly identical yields, which average out to be better than any of the yields obtained prior to cooperation. ...
    Article
    Full-text available
    For centuries Balinese rice farmers have been engaged in cooperative agricultural practices. Without centralized control, farmers have created a carefully coordinated system that allows productive farming in an ecosys-tem that is rife with water scarcity and the threat of disease and pests. We develop a simple game-theoretic model, inspired by a generation of careful anthropological field work, to provide a compact explanation for many of the most salient features observed in the system. We find that
  • ... Despite calls to incorporate niche construction as an alternative to models of human–environment interaction that typically consider only the way humans respond to environmental conditions (behavioral ecology), the two approaches can be integrated by drawing on complex adaptive systems theory where human–environment interactions at larger spatial and temporal scales are an emergent property of a coevolved social-ecological system maintained by short-term benefits to individual agents (Lansing 2003, Lansing & Fox 2011, Lansing et al. 1998). The putative weaknesses of behavioral ecology in explaining complex phenomena such as subsistence intensification can be overcome by an approach that integrates across spatial scales and considers the dynamic feedbacks among subsistence, ecological structure, and social organization. ...
    Article
    Full-text available
    New approaches to human-environment interactions are beginning to move beyond a narrow focus on individuals and simple (patch-level) predatory or competitive interactions. These approaches link nonequilibrium theory from community and landscape ecology with theories of individual decision making from behavioral ecology to explore new ways of approaching complex issues of diachronic change in behavior, subsistence, and social institutions. I provide an overview of two such approaches, one to understand long-term hunting sustainability among mixed forager-horticulturalists in the wet tropics and the other to understand how foragers act as ecosystem engineers in a dry perennial grassland in Australia. I conclude by describing the implications of new approaches that incorporate anthropogenic "intermediate" disturbance (an emergent property of human-environment interaction) as a force shaping environments through time and space, and in so doing patterning the sustainability of subsistence, ways of sharing, ownership norms, and even structures of gendered production.
  • ... staggered cropping schedules for entire watersheds . . . the actual patterns [we] have observed in the field bear a very close resemblance to computer simulations of optimal solutions " (Lansing 2000, p. 313). In subsequent experiments, we pursued the kinds of questions Kauffman posed in The Origins of Order, such as the relationship between the structure of connections between farming communities (subaks) and the ability of the entire collection of subaks to self-organize (Lansing et al. 1998). In the Balinese case, global control of terrace ecology emerges as local actors strike a balance between two opposing constraints: water stress from inadequate irrigation flow and damage from rice pests such as rats and insects. ...
    Article
    Full-text available
    ▪ Abstract The study of complex adaptive systems, a subset of nonlinear dynamical systems, has recently become a major focus of interdisciplinary research in the social and natural sciences. Nonlinear systems are ubiquitous; as mathematician Stanislaw Ulam observed, to speak of “nonlinear science” is like calling zoology the study of “nonelephant animals” (quoted in Campbell et al. 1985, p. 374). The initial phase of research on nonlinear systems focused on deterministic chaos, but more recent studies have investigated the properties of self-organizing systems or anti-chaos. For mathematicians and physicists, the biggest surprise is that complexity lurks within extremely simple systems. For biologists, it is the idea that natural selection is not the sole source of order in the biological world. In the social sciences, it is suggested that emergence—the idea that complex global patterns with new properties can emerge from local interactions—could have a comparable impact.
  • Article
    This paper deals with the spread of natural gas as a fuel for motor vehicles. Working on the basis of an input-oriented (and life cycle) approach to environmental issues, it is easy to show that natural gas is often relatively clean in comparison to all the other alternatives. Although natural gas is both cheap and very well suited to motoring uses, natural gas vehicles (NGVs) have not achieved widespread diffusion. This is particularly puzzling in Italy, as the relative price after taxes (in caloric equivalents) of natural gas is about 0.3 against gasoline and 0.4 against diesel fuel. The sample survey conducted confirms not only the practical drawbacks of NGVs — mainly the lack of an adequate refueling network — but also a profound lack of information and knowledge about NGVs characteristics. The overall indication for future policy is that economic incentives alone may not be sufficient. An environmental policy aimed at promoting ‘more sustainable’ individual choices (NGVs, in this case) must both consider the institutional framework, and promote the initial spread of appropriate understanding and awareness able to prime the endogenous adoption of ‘greener’ behaviors.
  • Article
    Evolutionary biology is experiencing an exceptional process of revision and outreach because of the 200-anniversary if the birth of Charles Darwin. As a consequence, the study of organic evolution and also its teaching are being discussed at several levels, by evolutionary biologists, biologists and scholars outside evolutionary biology and by the general public. In this scenario, a didactic explanation of how biologists address evolutionary research in real populations seems to be useful. Using actual research examples, here I tried to outline how the classic theory (termed here as the "basic scheme") is useful to answer relevant questions in biology and how a less dogmatic paradigm (or a more versatile one) would be needed when dealing with the most recent and extravagant cases of gene, genotype, phenotype and environment interactions. Specifically, I used three in-extenso examples of research driven by hypothesis-testing: (1) the changes in genetic architecture induced by sexuality in a cyclically parthenogenetic insect; (2) the test of the energetic definition of fitness through phenotypic selection studies; and (3) the assessment of the underlying causes of character displacement in Darwin finches. In the former two cases, it is argued that the basic scheme is useful and sufficient for testing relevant evolutionary hypotheses. In the third case, it is argued that something else is needed to explain the observed genetic variation that Geospiza species exhibit in Daphne major island (Galapagos). Finally, I outline some "extravagant" cases biological entities interacting, such as horizontal gene transfer, epigenetic inheritance, adaptive anticipatory conditioning, evolutionary capacitance and niche construction. This "post-modern" biology has been seriously proposed and demonstrated to be widespread in nature, which would justify an extended evolutionary synthesis.
  • Article
    The question on the essence of life as phenomenon is the key one for astrobiology, since the answer to this question determines “breadth of our outlook”. Taking Earth's version of life as the pattern extremely under-estimates our estimation of the probability of life origin and respectively expected probability of extraterrestrial life discovery. In the paper the hypothetical key attribute of life in general is selected on the base of comparative analyses and deductive inference. Simulation conducted on the base of neural network model shows that the same function could be realized by means of great variety of structures, which originated in the course of an evolutionary process. So multiplicity of evolutionary outcomes essentially increases the probability of final result – realization of an integrated function providing fitness to environment. Life as the integrated function can be realized via great variety of development ways and structures. A logical consequence of definitions for life as phenomenon is suggested. Final one is “Life is specific organization of informational and energetic processes coupling, enabling choice-making, and displayed as anomalies of different kinds”. Anomalies of visible form, mechanical movement, chemical composition and noticeable response are considered. Presented in the paper sweeping generalization is not rigorously proven, however it can play heuristic role in increasing the level of specificity of searching for extraterrestrial life.
  • Article
    A decade after the “Sokal Hoax,” Alan Sokal and Paul Boghossian still claim that postmodern arguments are incoherent attacks on reason and truth. However, both also continue to mischaracterize “constructivist” epistemology, to engage in highly problematic logical gymnastics to defend their own views, and to ignore changes in philosophy of science and science studies since 19963. 1996 What the Sokal Hoax ought to Teach Us. In Times Literary Supplement, December 13 , 14–15. View all references. I offer a brief description of my own, rather different understanding of postmodern science criticism in order to contextualize my dissatisfaction with Sokal and Boghossian's arguments, and to highlight the value of cross-subfield anthropological collaboration based on the constructivist perspective articulated by Barbara Herrnstein Smith.
  • Article
    An extensive empirical literature has demonstrated the existence of density-dependent selection in organizational vital rates. This research has also shown that historical trajectories followed by organizational populations only partly conform to the predictions of the original model. Inconsistencies with the model's predictions prompt a series of questions: Why do organizational populations suddenly collapse after reaching a peak? Why do organizational populations oscillate after collapsing? What causes extinction of organizational forms? To address these questions, scholars have proposed a variety of modifications to the original model of density dependence. All have merit, but none is completely satisfying. The main objective of this study is to narrow the gap between theories, models, and observed historical trajectories by identifying a unitary analytical framework that can account for the variety of empirical trajectories typically followed by mature organizational populations. The model that we present is based on the hypothesis of system-dependent selection, according to which patterns of resource availability are produced by processes that are partly endogenous to organizational populations. The main analytical insight of the study is that under conditions of dynamic resource constraints introduced by system-dependent selection, the presence of population-level inertia leads to a rich variety of historical trajectories during population maturity. We show that this result holds in the absence of any particular assumption about the microstructure of organizational populations. Possible trajectories include sustained oscillations, resurgence, and extinction.
  • Article
    ABSTRACT Anthropologists often disagree about whether, or in what ways, anthropology is “evolutionary.” Anthropologists defending accounts of primate or human biological development and evolution that conflict with mainstream “neo-Darwinian” thinking have sometimes been called “creationists” or have been accused of being “antiscience.” As a result, many cultural anthropologists struggle with an “anti-antievolutionism” dilemma: they are more comfortable opposing the critics of evolutionary biology, broadly conceived, than they are defending mainstream evolutionary views with which they disagree. Evolutionary theory, however, comes in many forms. Relational evolutionary approaches such as Developmental Systems Theory, niche construction, and autopoiesis–natural drift augment mainstream evolutionary thinking in ways that should prove attractive to many anthropologists who wish to affirm evolution but are dissatisfied with current “neo-Darwinian” hegemony. Relational evolutionary thinking moves evolutionary discussion away from reductionism and sterile nature–nurture debates and promises to enable fresh approaches to a range of problems across the subfields of anthropology. [Keywords: evolutionary anthropology, Developmental Systems Theory, niche construction, autopoeisis, natural drift]
  • Article
    Industrial global software processes include the activities of developers, users, sales and support personnel and their managers. Equally important is the feedback between them. Findings of empirical software engineering and other studies may not scale-up to such processes. Their study and that of the many environments in and for which they are pursued may be tackled by combining top-down and bottom-up approaches, broadening the scope and scale, and by following multidisciplinary investigative methods, tools and experience. Some of the latter may be inspired in numerical ecology, a discipline that suggests hints at the solution of issues inevitably emerging during broad scope and wide scale investigations.
  • Chapter
    Agent-based modelling on a computer appears to have a special role to play in the development of social science and the formulation of social policy. It offers a means of discovering general and applicable social theory, and grounding it in precise assumptions and derivations, whilst addressing those elements of individual cognition that are central to human society. However, there are important questions to be asked and difficulties to be overcome in achieving this potential. What differentiates agent-based modelling from traditional computer modelling? What different types of agent-based models are there, and what are the structural relationships between them (if any)? Which model types should be used in which circumstances? If it is appropriate to use a complex model, for example one incorporating “deliberative” agents, how can it be validated? If it can only be validated in general terms, does this mean that we are forced into a “theory building” mode in which the focus of the investigation lies in the model’s properties? If so, what types of parameter space may a complex model have? How best can very large parameter spaces be explored? Some of these questions are here addressed and are illustrated by reference to recent agent-based models for the environment. A particular application is then considered in some detail: agent-based modelling of intervention strategies for integrated ecosystem management, especially management of the Fraser River watershed in British Columbia.
  • Article
    Full-text available
    This chapter focuses on articulating elements of a new dynamic perspective that is emerging from the application of self-organizing and complex adaptive systems (CAS) in ecology. New dynamic perspective is the largest contribution that complex systems dynamics is currently making to ecology today. First, it discusses some of the various complex dynamics traditions that form the intellectual backdrop for the new dynamic perspective in ecology. Further, it identifies more features of complex dynamic models in general. The mathematical techniques for modelling complex systems fall into two distinct categories. Standard dynamic models employ (normally, ordinary) differential equations to construct models of systems dynamics. These equations enable follow the "flow" of the system variables through state space. Such systems are continuous in space and time. The network models of complex adaptive systems instead employ transition rules characterizing the interaction between individual elements. These systems are discrete in space and time. The differences in the mathematical properties of these types of systems can cause subtle and difficult issues. In addition, it discusses some important philosophic implications of applying complex systems dynamics to new paradigm in ecology.
  • Book
    The seemingly innocent observation that the activities of organisms bring about changes in environments is so obvious that it seems an unlikely focus for a new line of thinking about evolution. Yet niche construction--as this process of organism-driven environmental modification is known--has hidden complexities. By transforming biotic and abiotic sources of natural selection in external environments, niche construction generates feedback in evolution on a scale hitherto underestimated--and in a manner that transforms the evolutionary dynamic. It also plays a critical role in ecology, supporting ecosystem engineering and influencing the flow of energy and nutrients through ecosystems. Despite this, niche construction has been given short shrift in theoretical biology, in part because it cannot be fully understood within the framework of standard evolutionary theory. Wedding evolution and ecology, this book extends evolutionary theory by formally including niche construction and ecological inheritance as additional evolutionary processes. The authors support their historic move with empirical data, theoretical population genetics, and conceptual models. They also describe new research methods capable of testing the theory. They demonstrate how their theory can resolve long-standing problems in ecology, particularly by advancing the sorely needed synthesis of ecology and evolution, and how it offers an evolutionary basis for the human sciences. Already hailed as a pioneering work by some of the world's most influential biologists, this is a rare, potentially field-changing contribution to the biological sciences.
  • Article
    Full-text available
    Daisyworld is a simple planetary model designed to show the long-term effects of coupling between life and its environment. Its original form was introduced by James Lovelock as a defense against criticism that his Gaia theory of the Earth as a self-regulating homeostatic system requires teleological control rather than being an emergent property. The central premise, that living organisms can have major effects on the climate system, is no longer controversial. The Daisyworld model has attracted considerable interest from the scientific community and has now established itself as a model independent of, but still related to, the Gaia theory. Used widely as both a teaching tool and as a basis for more complex studies of feedback systems, it has also become an important paradigm for the understanding of the role of biotic components when modeling the Earth system. This paper collects the accumulated knowledge from the study of Daisyworld and provides the reader with a concise account of its important properties. We emphasize the increasing amount of exact analytic work on Daisyworld and are able to bring together and summarize these results from different systems for the first time. We conclude by suggesting what a more general model of life-environment interaction should be based on.
  • Chapter
    Full-text available
    The archaeological record has been described as a key to the long-term consequences of human action that can help guide our decisions today. Yet the sparse and incomplete nature of this record often makes it impossible to inferentially reconstruct past societies in sufficient detail for them to serve as more than very general cautionary tales of coupled socio-ecological systems. However, when formal and computational modeling is used to experimentally simulate human socioecological dynamics, the empirical archaeological record can be used to validate and improve dynamic models of long term change. In this way, knowledge generated by archaeology can play a unique and valuable role in developing the tools to make more informed decisions that will shape our future. The Mediterranean Landscape Dynamics project offers an example of using the past to develop and test computational models of interactions between land-use and landscape evolution that ultimately may help guide decision-making.
  • Article
    The theory of system-dependent organizational evolution is a recent attempt to provide a coherent analytical framework for exploring the feedback mechanisms that link changes in numbers of organizations in a population to changes in patterns of resource availability. According to the theory, organizations are both consumers as well as producers of resources. This view has at least two implications for the way in which we think about the relation between organizations and their environments. The first is that the carrying capacity for organizational populations cannot be constant over time. The second is that the carrying capacity changes as a function of density - the number of organizations in a population. If the feedback view behind the theory is correct, the level of organizational density and the level of relevant resources are simultaneously determined. So far, the theory of system dependent organizational evolution has been validated only through computer simulation. In this paper we use data that we have collected on the population of US television station during the period 1940-2000 to subject some of the core propositions of the theory to empirical test. The preliminary results that we report in this paper provide strong support for some of the main predictions of the theory.
  • Book
    Along rivers in Bali, small groups of farmers meet regularly in water temples to manage their irrigation systems. They have done so for a thousand years. Over the centuries, water temple networks have expanded to manage the ecology of rice terraces at the scale of whole watersheds. Although each group focuses on its own problems, a global solution nonetheless emerges that optimizes irrigation flows for everyone. Did someone have to design Bali's water temple networks, or could they have emerged from a self-organizing process? Perfect Order--a groundbreaking work at the nexus of conservation, complexity theory, and anthropology--describes a series of fieldwork projects triggered by this question, ranging from the archaeology of the water temples to their ecological functions and their place in Balinese cosmology. Stephen Lansing shows that the temple networks are fragile, vulnerable to the cross-currents produced by competition among male descent groups. But the feminine rites of water temples mirror the farmers' awareness that when they act in unison, small miracles of order occur regularly, as the jewel-like perfection of the rice terraces produces general prosperity. Much of this is barely visible from within the horizons of Western social theory. The fruit of a decade of multidisciplinary research, this absorbing book shows that even as researchers probe the foundations of cooperation in the water temple networks, the very existence of the traditional farming techniques they represent is threatened by large-scale development projects.
  • Article
    Full-text available
    The modern evolutionary theory, understood as the integration of the empirically-demonstrated theoretical foundations of organic evolution, is one of the most pervasive conceptual frameworks in biology. However, some debate has arisen in the Chilean scientific community regarding the legitimacy of natural selection as a mechanism that explains adaptive evolution. This review surveys the recent evidence for natural selection and its consequences on natural and artificial populations. In addition to the literature review, I present basic conceptual tools for the study of microevolution at the ecological scale, from a quantitative point of view. The outcome is clear: natural selection can be, is being, and has been quantified and demonstrated in both the field and in the laboratory,not many, but hundred of times during the past decades. The study of evolution by natural selection has attained maturity, which is demonstrated by the appearance of several syntheses and meta-analyses, as well as "evolutionary applications" where evolution by natural selection is used to resolve practical problems in disciplines other than pure biology. Caution is required when challening evolutionary theory. The abundant evidence supporting this conceptual body demands a careful examination of available evidence before dogmatically critizing its theoretical foundations
  • Article
    Full-text available
    Evolutionary biology is experiencing an exceptional process of revisión and outreach because of the 200-anniversary if the birth of Charles Darwin. As a consequence, the study of organic evolution and also its teaching are being discussed at several levels, by evolutionary biologists, biologists and scholars outside evolutionary biology and by the general public. In this scenario, a didactic explanation of how biologists address evolutionary research in real populations seems to be useful. Using actual research examples, here I tried to outline how the classic theory (termed here as the "basic scheme") is useful to answer relevant questions in biology and how a less dogmatic paradigm (or a more versatile one) would be needed when dealing with the most recent and extravagant cases of gene, genotype, phenotype and environment interactions. Specifically, I used three in-extenso examples of research driven by hypothesis-testing: (1) the changes in genetic architecture induced by sexuality in a cyclically parthenogenetic insect; (2) the test of the energetic definition of fitness through phenotypic selection studies; and (3) the assessment of the underlying causes of character displacement in Darwin finches. In the former two cases, it is argued that the basic scheme is useful and sufficient for testing relevant evolutionary hypotheses. In the third case, it is argued that something else is needed to explain the observed genetic variation that Geospiza species exhibit in Daphne major island (Galapagos). Finally, I outline some "extravagant" cases biological entities interacting, such as horizontal gene transfer, epigenetic inheritance, adaptive anticipatory conditioning, evolutionary capacitance and niche construction. This "post-modern" biology has been seriously proposed and demonstrated to be widespread in nature, which would justify an extended evolutionary synthesis.
  • Article
    The modern evolutionary theory, understood as the integration of the empirically-demonstrated theoretical foundations of organic evolution, is one of the most pervasive conceptual frameworks in biology. However, some debate has arisen in the Chilean scientific community regarding the legitimacy of natural selection as a mechanism that explains adaptive evolution. This review surveys the recent evidence for natural selection and its consequences on natural and artificial populations. In addition to the literature review, I present basic conceptual tools for the study of microevolution at the ecological scale, from a quantitative point of view. The outcome is clear: natural selection can be, is being, and has been quantified and demonstrated in both the field and in the laboratory, not many, but hundred of times during the past decades. The study of evolution by natural selection has attained maturity, which is demonstrated by the appearance of several syntheses and meta-analyses, as well as "evolutionary applications" where evolution by natural selection is used to resolve practical problems in disciplines other than pure biology. Caution is required when challenging evolutionary theory. The abundant evidence supporting this conceptual body demands a careful examination of available evidence before dogmatically critizing its theoretical foundations.
  • Sociocultural evolution is defined as the permanent interplay between the evolution of social order, cultural achievements and cognitive ontogenetic development. The key concept is that of social roles that are defined as a set of social rules and role specific knowledge. Sociocultural evolution accordingly is defined as the enlargement and variation of roles and in their social and cognitive dimension and as the variation of the relations between roles. The main theoretical thesis is the hypothesis of heterogeneity: sociocultural evolution is possible only if the degree of role autonomy in a particular society is large enough. A computational model, the sociocultural-cognitive algorithm is described that captures the main features of the evolution of societies. In particular it can be shown via the model why the hypothesis of heterogeneity is so important: it explains the special way of Western culture that was able totranscendcultural thresholds that limited the evolution of comparable societies.
  • Article
    Full-text available
    The origin of political- economic action by means of institutional selection: Some steps toward an evolutionary political economics. This essay takes some initial steps toward an evolutionary political economics by proposing to consider social, political, economic and cultural action subject to (a) variation, (b) (institutional) selection, and (c) ‘inheritence’ in tradition, experience, investments, etc., i.e. the three preconditions for a ‘social action evolution’ of Darwinian type. It draws from a number of conceptual sources, including dynamic and non-linear models in political science, sociology, economics, economic history, research policy, and most notably 'memetics' (i.e. the new discipline created on the basis of Richard Dawkins' theory of 'memes' - culturgenes - in The Selfish Gene 1976 and The Extended Phenotype 1982), however in this text divorced from the socio-biological notion of ‘culture’ as subordinated to biology. A number of propositions are made on the basis of analogies with theoretical biology however, e.g. an analogy between Robert Dahl's theory of paths toward polyarchy (democratization) and Sewall Wright's theory of adaptive landscapes; a solution to the problem of Lamarckian evolution-of-institutions and innovations as suggested by Douglass North and other prominent scholars in evolutionary and institutional economics and technology policy; the question of rapid innovation 'arms races'; and a memetic interpretation of Schumpeterian ‘new combinations’. Since the adoption of this approach equals a paradigm shift also for political science, and we are all'interested in what such a paradigm shift will bring to our discipline, an analogy is made with Nico Tinbergen's ‘Four Evolutionary Questions Why’, i.e. his strategy for developing ethology as a new approach in biology.
  • Chapter
    Full-text available
    The Daisyworld model describes an imaginary planet on which a regulation of the temperature emerges out of a strong coupling between life and its environment. This numerical simulation was initially created to answer to a theoretical critique adressed to the Gaïa hypothesis (GH). By precising the epistemic reach of Daisyworld and the nature of the critiques made to GH and then to Daisyworld we assess under which conditions such a model can contribute to the theoretical debate that brought it to existence. We show that certain results are robust, originals and relevant for GH.
  • Chapter
    This paper describes the design phase of an ABM case study of Bali irrigation. The aim of the model is to explain the differences in the ability of rice paddy farmers to collectively adapt through cooperation. The model should allow exploring factors affecting self organisation within and between rice paddy farmer communities. The exercise of the ABM case study aims to move abstract models (theory) closer to real world phenomena, which requires contextualisation. This paper focuses on the first steps in model contextualisation: model selection and specification for the Bali irrigation case.
  • Article
    Using three different models we demonstrated that global warming is a possible explanation of the decrements of arrow bamboos in Mount Shennongjia and we predict shifts upwards on the distribution of bamboos and a possible extinction under different scenarios(Temperature increments of 1.5° C,4°C and 6 °C) of global warming.
  • Article
    Full-text available
    In both biology and the human sciences, social groups are sometimes treated as adaptive units whose organization cannot be reduced to individual interactions. This group-level view is opposed by a more individualistic one that treats social organization as a byproduct of self-interest. According to biologists, group-level adaptations can evolve only by a process of natural selection at the group level. Most biologists rejected group selection as an important evolutionary force during the 1960s and 1970s but a positive literature began to grow during the 1970s and is rapidly expanding today. We review this recent literature and its implications for human evolutionary biology. We show that the rejection of group selection was based on a misplaced emphasis on genes as “replicators” which is in fact irrelevant to the question of whether groups can be like individuals in their functional organization. The fundamental question is whether social groups and other higher-level entities can be “vehicles” of selection. When this elementary fact is recognized, group selection emerges as an important force in nature and what seem to be competing theories, such as kin selection and reciprocity, reappear as special cases of group selection. The result is a unified theory of natural selection that operates on a nested hierarchy of units.The vehicle-based theory makes it clear that group selection is an important force to consider in human evolution. Humans can facultatively span the full range from self-interested individuals to “organs” of group-level “organisms.” Human behavior not only reflects the balance between levels of selection but it can also alter the balance through the construction of social structures that have the effect of reducing fitness differences within groups, concentrating natural selection (and functional organization) at the group level. These social structures and the cognitive abilities that produce them allow group selection to be important even among large groups of unrelated individuals.
  • Article
    Full-text available
    Population dynamics ofNephotettix virescens was studied in 17 paddy fields transplanted at intervals of about 1 month in 1988–1990. The adult density was highest either in the immigrant or the 1st generation and sharply decreased to the 2nd generation. The survival rate of the 1st generation was lowest in the transition season when areal population density increased. Key factor analysis revealed that the nymphal and adult mortality of the 1st generation (kn) was the principal source of population fluctuations. No significant correaltion was found between kn and natural enemy density, natural enemy density/healthy egg density, or the precipitation during the nymphal period. On these bases adult emigration was suspected to be the key factor. Areal population build-up ofN. virescens in the transition season was considered to occur as a result of increasing immigration to young stages of rice.
  • Article
    Full-text available
    For over a thousand years, generations of Balinese farmers have gradually transformed the landscape of their island, clearing forests, digging irrigation canals, and terracing hillsides to enable themselves and their descendants to grow irrigated rice. Paralleling the physical system of terraces and irrigation works, the Balinese have also constructed intricate networks of shrines and temples dedicated to agricultural deities. Ecological modeling shows that water temple networks can have macroscopic effects on the topography of the adaptive landscape, and may be representative of a class of complex adaptive systems that have evolved to manage agroecosystems.
  • Article
    Full-text available
    Ecosystem engineers are organisms that directly or indirectly modulate the availability of resources to other species, by causing physical state changes in biotic or abiotic materials. In so doing they modify, maintain and create habitats. Autogenic engineers (e.g. corals, or trees) change the environment via their own physical structures (i.e. their living and dead tissues). Allogenic engineers (e.g. woodpeckers, beavers) change the environment by transforming living or non-living materials from one physical state to another, via mechanical or other means. The direct provision of resources to other species, in the form of living or dead tissues is not engineering. Organisms act as engineers when they modulate the supply of a resource or resources other than themselves. We recognise and define five types of engineering and provide examples. Humans are allogenic engineers par excellence, and also mimic the behaviour of autogenic engineers, for example by constructing glasshouses. We explore related concepts including the notions of extended phenotypes and keystone species. Some (but not all) products of ecosystem engineering are extended phenotypes. Many (perhaps most) impacts of keystone species include not only trophic effects, but also engineers and engineering. Engineers differ in their impacts. The biggest effects are attributable to species with large per capita impacts, living at high densities, over large areas for a long time, giving rise to structures that persist for millennia and that modulate many resource flows (e.g. mima mounds created by fossorial rodents). The ephemeral nests constructed by small, passerine birds lie at the opposite end of this continuum. We provide a tentative research agenda for an exploration of the phenomenon of organisms as ecosystem engineers, and suggest that all habitats on earth support, and are influenced by, ecosystem engineers.
  • Article
    Several evolutionary models in distinct biological fields—population genetics, population ecology, early biochemical evolution and sociobiology—lead independently to the same class of replicator dynamics.
  • Article
    The relationship between density-dependent population growth and frequency- and density-dependent selection was investigated. For the haploid asexual case, Malthusian growth leads to constant birth and death rates and constant fitness values. A more general Lotka-Volterrra formulation leads to both density- and frequency-dependent selection. The more general formulation is necessary but not sufficient for polymorphic coexistence in asexual forms. For the diploid sexual case, Malthusian growth leads to frequency-dependent population trajectories, but the basic birth and death rates are constant. A density-dependent model, analogous to the Lotka-Volterra model of the asexual case, leads to both frequency- and density-dependent fitness values and selection differentials. If selective differentials are solely reproductive in origin, whether density dependent or independent, Hardy-Weinberg frequencies characterize the polymorphic equilibrium, when it exists. This is not the case when selection differentials involve survival components, whether density dependent or independent. It is shown that heterosis is not necessary to achieve stable polymorphism and that the polymorphic condition can be maintained by certain types of intergenotypic competition as well.
  • Article
    1. Most organisms interact with a set of neighbors smaller than the deme (its trait group). Demes therefore are not only a population of individuals but also a population of groups (structured demes). 2. Trait groups vary in their composition. The minimum variance to be expected is that arising from a binomial distribution. Most populations have a higher variance than this due to (a) differential interactions with the environment and (b) the effects of reproduction inside the trait groups. 3. As a consequence of this variation, an individual on the average experiences its own "type" in a greater frequency than actually exists in the deme. Its behaviors are therefore directed differentially toward fellow types, and this is the fundamental requirement for the evolution of altruism. 4. Models are presented for warning cries and other donor-recipient relations, resource notification, the evolution of prudence in exploitation and interference competition, and the effect of differential trait-group extinction. ...
  • Article
    The original Lotka-Volterra model. See also Lotka (1925).
  • Article
    The biota have effected profound changes on the environment of the surface of the earth. At the same time, that environment has imposed constraints on the biota, so that life and the environment may be considered as two parts of a coupled system. Unfortunately, the system is too complex and too little known for us to model it adequately. To investigate the properties which this close-coupling might confer on the system, we chose to develop a model of an imaginary planet having a very simple biosphere. It consisted of just two species of daisy of different colours and was first described by Lovelock (1982). The growth rate of the daisies depends on only one environmental variable, temperature, which the daisies in turn modify because they absorb different amounts of radiation. Regardless of the details of the interaction, the effect of the daisies is to stabilize the temperature. The result arises because of the peaked shape of the growth-temperature curve and is independent of the mechanics by which the biota are assumed to modify the temperature. We sketch out the elements of a biological feedback system which might help regulate the temperature of the earth.
  • Article
    We used a simulation model of forest dynamics to examine the ecological significance of the complex interactions among site conditions, tree growth, and the development of a thick forest floor moss layer found in many boreal forests. To examine the effect of site conditions on moss growth and forest dynamics, we simulated the dynamics of several different forest sites in the uplands of interior Alaska. Then we used a cold, wet permafrost site to examine the ecological consequences of direct moss and tree interactions. Our analyses revealed a tightly coupled system in which forest succession was highly sensitive to the interactions among site conditions, mosses, and trees. The effect of mosses on the soil thermal regime was a particularly important feedback. Direct interactions between mosses and trees that affected the development of a thick forest floor layer were also important. In particular, shading of moss by trees, reduced tree regeneration on moss-covered soils, and reduced moss growth with open forest canopies were also important determinants of forest succession. These complex feedbacks ensure that an ecosystem approach is needed to understand the ecology of boreal forests.
  • Article
    In an unpredictably changing environment, phenotypic variability may evolve as a "bet-hedging" strategy We examine here two models for evolutionarily stable phenotype distributions resulting from stabilizing selection with a randomly fluctuating optimum. Both models include overlapping generations, either survival of adults or a dormant propagule pool. In the first model (mixed-strategies model) we assume that individuals can produce offspring with a distribution of phenotypes, in which case, the evolutionarily stable population always consists of a single genotype. We show that there is a unique evolutionarily stable strategy (ESS) distribution that does not depend on the amount of generational overlap, and that the ESS distribution generically is discrete rather than continuous; that is, there are distinct classes of offspring rather than a continuous distribution of offspring phenotypes. If the probability of extreme fluctuations in the optimum is sufficiently small, then the ESS distribution is monomorphic: a single type fitted to the mean environment. At higher levels of variability, the ESS distribution is polymorphic, and we find stability conditions for dimorphic distributions. For an exponential or similarly broad-tailed distribution of the optimum phenotype, the ESS consists of an infinite number of distinct phenotypes. In the second model we assume that an individual produces offspring with a single, genetically determined phenotype (pure-strategies model). The ESS population then contains multiple genotypes when the environmental variance is sufficiently high. However the phenotype distributions are similar to those in the mixed-strategies model: discrete, with an increasing number of distinct phenotypes as the environmental variance increases.
  • Article
    There is growing interest in applying nonlinear methods to evolutionary biology. With good reason: the living world is full of nonlinearities, responsible for steady states, regular oscillations, and chaos in biological systems. Evolutionists may find nonlinear dynamics important in studying short-term dynamics of changes in genotype frequency, and in understanding selection and its constraints. More speculatively, dynamical systems theory may be important because nonlinear fluctuations in some traits may sometimes be favored by selection, and because some long-run patterns of evolutionary change could be described using these methods.
  • Article
    Over the past few years, ecologists have increasingly recognized the existence of strong self-reinforcing (or self-organizing) interactions within systems at a variety of scales. Positive feedback within food chains has been reported from terrestrial and aquatic ecosystems. Accumulating evidence supports the existence within communities of cooperative guilds - tit-for-tat relationships based on diffuse mutualisms and favored by environmental unpredictability. At the landscape level, both real world experience and models indicate that processes such as hydrology and the propagation of disturbance can be strongly self-reinforcing (i.e. the landscape structure supports the process, and vice versa). Hence the picture emerges of a hierarchy of self-organizing systems that span food chains, communities and landscapes/regions.
  • Article
    Intraspecific competition implies interaction among the individuals of a population, so natural selection on genotypic variation in characters related to the competition will necessarily be frequency dependent. Intraspecific antagonistic competition exhibits properties similar to other behavioural interactions between individuals. In exploitative intraspecific competition the interactions among individuals are less direct. Exploitation modifies the abundance of the various limiting resources according to the use of these resources by the individual members of the population. The amount of resource available to an individual is therefore a function of the phenotypes present in the population, through their density and frequency.
  • Article
    A two-species genetic model of host-parasite interaction is used to study the dynamical consequences of varying the number of genotypes in each species, and the recombination rate in the host. With two genotypes in each species, the model's behaviour is very simple; there is either a stable interior equilibrium, a stable cycle or a smooth outward spiral toward the boundaries. But with three or more genotypes, complex cycles and apparently chaotic behaviour may arise over wide ranges of parameter values. Increasing the number of genotypes also tends to slow the rate of gene-frequency change. Recombination in the host does not affect the stability of the interior fixed point, but intermediate rates of recombination may give dynamic stability to an otherwise dynamically unstable pattern of cycling. Intermediate rates of recombination also tend to decrease the amplitudes of gene-frequency cycles in the host, which implies that they could promote the accumulation of genetic variation involved in complementary, antagonistic interactions with parasites.
  • Article
    There are many situations in which the direction and intensity of natural selection in bacterial populations will depend on the relative frequencies of genotypes. In some cases, this selection will favour rare genotypes and result in the maintenance of genetic variability; this is termed stabilizing frequency-dependent selection. In other cases, selection will only favour genotypes when they are common. Rare types cannot invade and genetic variability will not be maintained; this is known as disruptive frequency-dependent selection. Phage-mediated selection for bacteria with novel restriction-modification systems is frequency-dependent and stabilizing. In mass culture, selection for the production of toxins and allelopathic agents is likely to be frequency-dependent but disruptive. This also occurs in selection favouring genes and transposable elements that cause mutations. Here I review the results of theoretical and experimental studies of stabilizing and disruptive frequency-dependent selection in bacterial populations, and speculate on the importance of this kind of selection in the adaptation and evolution of these organisms and their accessory elements (plasmid, phage and transposons).
  • Article
    Daisyworld is a model dynamical system in which very simple mechanisms interact to produce complex behaviour. It was devised to show how regulation can arise without natural selection. Here we investigate the model in greater detail. We analyse the possible steady states and study the response of the system under different conditions, we consider the implications of the hysteresis which is found in this and many other non-linear systems, and we compare the properties of the model with those of systems that evolved solely by natural selection. Natural selection inherently concentrates on local optimization and immediate advantage rather than on robustness and long-term benefit. This makes some features of organisms hard to explain within the synthetic theory. The model suggests that the solution may simply be that natural selection was not the crucial factor in their evolution. When a system that has previously responded to challenge counter-intuitively or apparently not at all subsequently begins to react in the way one would expect, this should be taken as a warning that it is a regulated system and that the regulation may be about to break down. If that happens, there is likely to be a catastrophic change as the system either collapses altogether or else moves rapidly to the state it would have been in without regulation. Recovery, if possible at all, is likely to be unexpectedly difficult.
  • Life at the edge of chaos. The New York Review of Books
    • M S
    M S, J. (1995). Life at the edge of chaos. The New York Review of Books, 2 March, 28–30.
  • Adaptation and Natural Selection Structured demes and the evolution of group-advantageous traits
    • G C W
    W, G. C. (1966). Adaptation and Natural Selection. Princeton: Princeton University Press. W, D. S. (1977). Structured demes and the evolution of group-advantageous traits. Am. Nat. 111, 157–185.
  • The Extended Phenotype Darwinism Evolving: Systems Dynamics and the Genealogy of Natural Selection
    • R D
    • D J D
    • B H W
    D, R. (1982). The Extended Phenotype. Oxford and New York: Oxford University Press. D, D. J. & W, B. H. (1995). Darwinism Evolving: Systems Dynamics and the Genealogy of Natural Selection. Cambridge, MA: MIT Press.
  • The Theory of Evolution and Dynamical Systems Organisms as ecosystem engineers
    • J Oxford H
    • K S
    • C G J
    • J H L
    • M S
    Oxford: Clarendon Press. H, J. & S, K. (1988). The Theory of Evolution and Dynamical Systems. Cambridge: Cambridge University Press. J, C. G., L, J. H. & S, M. (1994). Organisms as ecosystem engineers. Oikos 69, 373–386.
  • Statistical Records Office The Origins of Order: Self-organization and Selection in Evolution Is there a constant fitness value for a given genotype? No! Evolution
    • K S
    K S B (1986). Statistical Records Office, Government of Indonesia. K, S. (1993). The Origins of Order: Self-organization and Selection in Evolution. Oxford: Oxford University Press. K, K. (1971). Is there a constant fitness value for a given genotype? No! Evolution 25, 281–285.