Search Results

Foundational changes are taking place in the understanding of human groups. For decades, the biological and social sciences have been dominated by a form of individualism that renders groups as nothing more than collections of self-interested individuals. Now groups themselves are being interpreted as adaptive units, organisms in the own right, in which individuals play supportive roles. This chapter attempts to establish a permanent consensus for human groups as adaptive units, based on multilevel selection theory.

This chapter explores the modeling of multilevel selection (MLS) – and the related concepts of group selection and kin selection – using variance partitioning methods, using the Price equation to elucidate basic issues within MLS theory. An expansion of this theory, based on contextual analysis and direct fitness, is used to show that kin selection and MLS selection have the same mathematical roots, although they are not identical. Kin selection theory is oriented towards identifying the optimal group and individual level traits that maximize the fitness of an organism, while MLS theory is oriented towards identifying the rate of evolution of the group and individual level traits in a specified situation. Because of these differences, kin selection and group selection can be considered as complementary approaches. The chapter also addresses why heritable variation at one level often bears little relation to heritable variation at other levels. It is shown that interactions among units (e.g., individuals) cannot contribute to a response to selection at that level, but can contribute to response to selection at a higher level (e.g., the population). Thus, the response to selection at one level can be qualitatively different than the response to selection at other levels.

This chapter examines which of the equivalent alternative partitions of fitness, including inclusive fitness and group fitness, can be interpreted as being subject to natural selection in a meaningful way. Inclusive fitness theory can deal with subtleties such as nonadditive fitness effects and conditionally expressed phenotypes. However, selection based on inclusive fitness gives equivalent predictions to other models of apparently different evolutionary processes, such as multilevel selection. The chapter considers how we can determine whether inclusive fitness really captures the essence of social evolution and whether inclusive fitness is really maximized by the action of selection, as suggested by William D. Hamilton. It also explains what heritability measures, and whether this makes sense biologically. Finally, it discusses the problem of classifying observed social behaviors in terms of their underlying evolutionary explanations.

This book demonstrates the generality of inclusive fitness theory, with particular emphasis on its fundamental evolutionary logic. It presents the basic mathematical theory of natural selection and shows how inclusive fitness theory deals with more complicated social scenarios. Topics include the Price equation, Hamilton's rule, nonadditive interactions, conditional behaviors, heritability, and maximization of inclusive fitness. This chapter provides a brief historical introduction to the problem of apparent design in biology, evolutionary explanations of this, and in particular, evolutionary explanations of individual behaviors that appear designed to benefit not the individual themselves, but other members of their species. It examines how social behaviors can be shaped by natural selection and discusses the problem of providing an evolutionary explanation of self-sacrifice by individuals, altruism in group selection, and multilevel selection theory.

Since Darwin, multilevel selection has been the key concept of the hierarchical approach to evolution. The debate around the significance of group selection as an evolutionary phenomenon (in both an early controversial version and subsequent mathematical definition) has been the main entrance to multilevel selection theories. We present here a historical sketch of the debate prior to the formalization proposed by Samir Okasha. We also consider two extensions of Okasha’s multilevel theory: the diachronic perspective made possible by the study of major evolutionary transitions; the cross-level exaptive by-products. The double hierarchy, first proposed by Niles Eldredge and Stanley Salthe is a different kind of multilevel approach to evolution that avoids some theoretical impasses produced by a strictly selection-centered approach to extend the levels of evolutionary change. We argue that a dual hierarchical approach has a major heuristic power in order to embrace the complexity of evolutionary phenomena, from molecules to ecosystems, and is a candidate for an updated and unifying meta-theory of evolutionary patterns.

This chapter explores one of the primary contributors to the emergence of macroecological patterns—multilevel natural selection to include selectivity at the species level. It considers the definition of the processes of selective extinction and speciation and provides a brief history of our understanding of them. The main focus of the chapter is a description of natural selection and the way it operates to include species. It shows how opposing forces lead to patterns, exemplified by natural selection at the individual/gene level that can lead to extinction (sometimes called evolutionary suicide)—a situation in which we humans likely find ourselves. A primary point of this chapter is that selectivity influences natural patterns to be included in the processes, dynamics, and factors that they reflect, thus bringing evolutionary enlightenment to management based on such patterns.

Chapter 4 begins to develop the case against biocentrism. Biocentrism faces a problem of exclusion; it is not possible to adopt the account of welfare defended in chapter 3 in a way that grounds the welfare of nonsentient organisms while excluding biological collectives or artifacts. Chapter 4 develops this problem of exclusion with respect to biological collectives. This requires consideration of an issue within the philosophy of biology: the problem of the levels or units of selection. The chapter argues that the biocentrist is committed to a view about the levels of selection that grounds the view that only individual organisms are teleologically organized. But among the views available concerning which things are ultimately subject to natural selection, none of them will serve as a foundation for biocentrism. The chapter argues that the correct view about the units of selection is one on which biological collectives are sometimes teleologically organized.

The phenotypes of those individuals with which an focal individual interacts often influences the trait value in the focal individual. Maternal effects is a classic example of this phenomena, as is fitness. If these traits are heritable, then the selection response depends on both the change in the direct effects influencing a target trait and the associative effects contributed by interacting individuals. In such a setting, the breeder's equation no longer holds, as the problem is now a multiple trait one. This chapter examines the theory of response under models with both direct and associative effects, which can lead to a reversed response (a trait selected to increase instead decreases). The evolution of behavioral traits, including the evolution of altruism, is best handled using this approach. Further, kin and group selection follow as special cases of the gerenal model under multilevel selection. This chapter also examines how mixed models can be used estimate model parameters.

This chapter contains a discussion of Maynard Smith’s conceptual distinction between kin and group selection. The author discusses the design and experimental study of kin selection for and against cannibalism as a test of the definitional distinction. The fallacy that societies are vulnerable to cheaters is discussed along with the concept of a “kin-selection mutation balance.” The results of models with three levels of selection as well as models of the effect of inbreeding on kin selection are presented. The synergistic coevolution of mating system and sociality are illustrated and the underlying processes governing the run-away evolution of sociality are discussed. The advantage of the multilevel selection perspective over the inclusive fitness perspective is illustrated by drawing from counter-factual predictions of inclusive fitness theory and its inability to account for underlying processes of genetic change.

This chapter develops the idea that the germ-soma split and the suppression of individual fitness differences within the corporate entity are not always essential steps in the evolution of corporate individuals. It illustrates some consequences for multilevel selection theory. It presents evidence that genetic heterogeneity may not always be a barrier to successful functioning as a higher-level individual. This chapter shows that levels-of-selection theorists are wrong to assume that the central problem in transitions is always that of minimizing within-group competition. Evidence of intralevel conflict does not qualify as evidence against the existence of a higher level of selection.

In his book Animal Dispersion in Relation to Social Behavior, ornithologist V. C. Wynne-Edwards argued that many enigmatic bird behaviors functioned to prevent over-population. The book generated a storm of controversy, and luminaries like George Williams and John Maynard Smith penned critiques explaining why this mechanism, then called “group selection,” could not work. The result was the beginning of an ongoing and highly successful revolution in our understanding of the evolution of animal behavior, a revolution that is rooted in carefully thinking about the individual and nepotistic functions of behavior. This chapter takes a general look at multilevel selection and shows that the Price equation also leads to a description of natural selection as going on in a series of nested levels: among genes within an individual, among individuals within groups, and among groups. It first discusses three views of selection according to personal fitness, inclusive fitness, and multilevel selection. It concludes by discussing the evolution of dispersal as an example of how multilevel selection can be used to clarify an important biological problem.

This chapter attempts to strengthen the conceptualization of selection in evolutionary international relations. It discusses multilevel (or hierarchical) selection theory, which takes as its starting point the idea that selection can operate simultaneously at different levels of a hierarchy, for instance, the ecological hierarchy in biology (organism, population, community, ecosystem). The chapter addresses the issue of ontology in evolutionary international relations, that is, the question of whether large-scale social entities actually exist with the capacity to act as causal agents (evolutionary individuals) in a process of selection.

In complex systems theory, two meanings of a complex adaptive system (CAS) need to be distinguished. The first, CAS1, refers to a complex system that is adaptive as a system; the second, CAS2, refers to a complex system of agents which follow adaptive strategies. Examples of CAS1 include the brain, the immune system, and social insect colonies. Examples of CAS2 include multispecies ecosystems and the biosphere. This chapter uses multilevel selection theory to clarify the relationships between CAS1 and CAS2. The general rule is that for a complex system to qualify as CAS1, selection must occur at the level of the complex system (e.g., individual-level selection for brains and the immune system, colony-level selection for social insect colonies). Selection below the level of the system tends to undermine system-level functional organization. This general rule applies to human social systems as well as biological systems and has profound consequences for economics and public policy.

This chapter calls for an approach to economic policy that takes evolutionary and complex systems theory into account. Such an approach alters the way that economic policy is framed and how policy co-depends on understanding markets as outcomes of nonmarket interactions, incomplete information, path dependency, and coordination failures. Through illustrative examples, it explores the application of evolutionary and complexity thinking to policy criteria, goals, instruments, and policy assessment. These examples—the transition to a low carbon economy, the use of multilevel selection to inform group design for human organizations, policy making as shaping and creating markets, government failures in Greek farm policy, and protecting the Sudd Wetland in South Sudan—are used to identify key issues for an evolutionary and complexity approach to public policy.

This chapter reviews the debate on group selection, a concept that has experienced vertiginous ups and downs since the 1960s, and brings it up to modern standards within the broader context of multilevel selection (MLS) theory. It specifically offers a brief overview of MLS theory, major evolutionary transitions, and human evolution as a major transition, so that these subjects can become part of an extended evolutionary synthesis. The chapter also describes how MLS theory relates to the Modern Synthesis. A comment on all aspects of human behavior and culture from an evolutionary perspective is then presented.

This chapter examines the basic institutional similarities between innovation commons (as a species of knowledge commons) and the eight core design principles, or rules of the commons, that Ostrom discovered. It explores the innovation commons through the lens of these rules that enable a group to form under uncertainty, and that make cooperation a safe and effective strategy within that group. The question is explored in terms of the core problems a commons must solve: identity, cooperation, consent, monitoring, punishment, and independence. The chapter then examines these rules in the broader context of multilevel selection theory, arguing that group selection operates over innovation.

In this chapter, my goals are threefold. First, I give a taxonomy of evolutionary explanations of cancer, illustrating distinct types with case studies of explanations of cancer’s origins and prevalence. Second, I argue that cancer progression can be viewed as both a process of selection and a byproduct of selection at distinct levels in the biological hierarchy. Third, I provide a general account of the explanatory role of theoretical models of cancer progression and treatment failure. I use these accounts to illustrate examples of “how possibly” and “a priori” causal modeling.

This chapter argues that the multilevel selection (MLS)-1 to MLS-2 model of a major transition is incomplete because it overlooks a crucial component of fitness. It addresses that the evolution of individuality literature has failed to account for expansive fitness and that expansive fitness differences play an important role in the transition to regimes sensitive to the fitness of the corporate agent. It discusses multilevel evolution during the three phases of transitions in individuality: the aggregate phase, the group phase, and the individual phase. This chapter shows that the path a lineage takes through the phases of transitions is not fixed, but determined by ecology.

This chapter presents a displacement of the organism as a privileged level of analysis in evolutionary biology. It is concerned with the ontology of biology systems, with particular reference to hierarchical organization. It argues that the concept of a rank-free hierarchy can be transposed to the major transitions hierarchy, with interesting consequences. This chapter shows that the idea of rank freedom makes good sense of a number of facets of the recent discussion of evolutionary transitions and multilevel selection. It suggests that the idea of rank freedom is already at work, implicitly, in much theorizing about evolutionary transitions and/or multilevel selection.

Less than 2% of the human genome is made up of the ~20,000 protein-coding genes. The remainder consists primarily of non-coding sequences of numerous types, such as introns, highly repetitive satellite DNA, defunct pseudogenes, and especially transposable elements (TEs). The latter make up at least half of the human genome sequence, with some TEs present in enormous numbers of copies; the primate-specific TE known as Alu, for example, is present in more than 1 million copies per genome. Any complete account of genome evolution therefore requires an understanding of transposable element biology and evolution. Unfortunately, there is a tendency to consider TEs largely from the level of the organism, especially whether or not they are “functional”. Here we discuss the need for a multi-level perspective that recognizes TEs at their own level, including their unique biological features, evolutionary histories, and interactions with the host and with each other.