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This chapter describes studies on two common dung fly species with contrasting sexual size dimorphism (SSD): females are the larger sex in Sepsis cynipsea but the smaller sex in Scathophaga stercoraria. In both species, there is overwhelming evidence for sexual and fecundity selection favouring large body size, but only sparse evidence for selection favouring small size in either sex. The absence of evidence of net balancing selection on either sex does not support the differential equilibrium model of SSD. For the yellow dung fly, S. stercoraria, the efforts taken to detect selection against large individuals were substantial, including multiple viability selection estimates covering a wide and representative range of environmental conditions and artificial extension by artificial selection of the body size range available. Therefore, undetected selection favouring small size is unlikely. Phylogenetic, genetic, or developmental constraints are also unlikely to be responsible for lack of support of the differential equilibrium model in dung flies, but physiological constraints have not yet been properly addressed.

The action of selection is based on a few simple principles that are general to all self-replicating systems, and which constitute a distinct branch of science. This introductory chapter presents a brief overview of some of these principles in a wide range of systems. It is divided into various sections on the following discussion topics: RNA viruses are the simplest self-replicators; exponential growth can be maintained by serial transfer; replication is always imprecise; imprecise replication leads to differential growth; selection acts directly on rates of replication; selection may act indirectly on other characters; the indirect response to selection is often antagonistic; evolution typically involves a sequence of alterations; the evolution of increased complexity is a contingent process; very improbable structures rapidly arise through the cumulation of alterations; competitors are an important part of the environment; evolution through selection is a property of self-replicators; self-replicating algorithms evolve in computers; and finally evolution through selection is governed by a set of general principles.

How important are metaphors and analogies in science and what form do they take? Peter Achinstein's Concepts of Science is the definitive modern lynchpin of this discussion in modern philosophy of science. Inspired by this work, this chapter look at the use of artificial selection in Charles Darwin's Origin of Species. This chapter argue that it has a three-fold role: heuristic, pedagogical, and justificatory. This chapter locate Darwin's use of artificial selection in the context of the nineteenth-century discussion about causation, and, in particular, what constitutes a true cause, or vera causa. This chapter argue that this all shows what a skilled methodologist Darwin was and how crucial metaphors and models are in science.

This chapter presents some of the methods in experimental evolution that can be used to study the evolution of behavior, illustrating how these can be applied toward understanding the origin and mechanisms of behavioral diversity. One method is artificial selection, a powerful tool used to explore the question of how behavior evolves; another is mass selection, which relies on an experimental setup that sorts individuals into groups depending on a particular behavior. An alternative approach for identifying mechanisms of behavioral evolution is to use experimental methods to explore genetics and physiology of real behavioral shifts that occurred among populations or species in nature. The chapter describes how laboratory experimental tools, such as genetic engineering and pharmacology, were used to discover the evolution of mating systems in voles.

Chapter 4 critically reads the ethos of cross-cultural collaboration promoted by this culture industry through the trope of musical hybridity. By theorizing the links between hybridity and miscegenation and their relationship to Darwin’s theory of natural selection, this chapter interrogates the heterosexual imperative at work in musical tropes of cross-fertilization and chronicles the gendered division of sonic labor. It begins by surveying work on music and cultural mixing (e.g., syncretism, hybridity, fusion) insisting upon an analysis of the sexual implications at the heart of these metaphors and interrogating their heterologic as a holdover of eugenicist practices of “artificial selection.” The chapter explores the discursive linkages uniting music, genetics, and adaptability in order to further map the resignification of the ear as an erotic orifice, one that has perhaps a greater capacity to adapt the listener to a rapidly changing anthropocene in which change has outpaced biological evolutionary time.

Chapter 8’s focus is on the genetic architecture of complex traits determined jointly by multiple genes and environmental factors. Sometimes called quantitative genetics, the basic concepts include components of genetic and environmental variance, genotype-by-environment interaction, genotype-by-environment association, correlation between relatives, and broad-sense and narrow-sense heritability. It distinguishes between physiological and statistical epistasis, and it shows why the former can be large while the latter may be negligible. Various types of artificial selection are considered, and individual truncation selection is examined in detail, culminating in the famous prediction equation R = h²S. Special topics include genomic selection, correlated response, selection limits, and the heritability of liability of threshold traits.

This chapter summarizes a more detailed discussion on what social evolution is as a phenomenon and as a paradigm developed elsewhere (Tang 2014-15). It also provides a brief critique of some of the evolutionary theorizing in IR. This chapter lays the foundation for applying SEP to empirical inquiries followed.

Chapter 6 deals with Darwin’s immersion in the practices of animal breeders and pigeon fanciers and his reconstitution of the notion of aesthetic preference by artificial selection. It is argued that, faced with the problematic of useless or potentially harmful male beauty in birds, Darwin shifted from an early inclination towards the dominant male role in any process of sexual selection to the realisation that, in animals, females generally must play the role of selector. He had to go against entrenched opinion in attributing not just a sense of beauty to animals, but further to insist that this aesthetic was primarily exercised through female sexual preference. His own thoroughgoing identification of the process of aesthetic choice with the discriminating, artistic eye of the breeder was a stumbling block to the notion of analogous female choice in nature. Female choice, already a challenging concept for a Victorian, was made doubly so for Darwin, confronting the seeming contradiction of extending the masculine, manipulative art of breeding to the sexual preferences of female animals.

This chapter discusses experiments on animal domestication carried out by Dmitri Belyaev in 1958. Using silver black foxes (Vulpes vulpes) as subjects, Belyaev explored the role of the stress of the artificial selection regime in domestication. Belyaev believed that reconstructing the early steps of animal domestication could provide a better understanding of the behavioral transformations and the variability of morphological traits and physiological functions that emerge in the domestication process.

This chapter draws on key concepts from evolutionary theory, anthropology, and social science to explore how adaptive enemies evolve and adapt under conditions of conflict. It identifies four key mechanisms of evolution in irregular warfare—social learning, natural selection, artificial selection (including both unconscious artificial selection and predator effects), and institutional adaptation—and gives examples of each. It also examines forms of conscious military innovation by states, and draws a distinction between peacetime (concept led) and wartime (reactive) modes of innovation. The chapter argues that domination of the operational environment by Western armed forces since the end of the Cold War has created evolutionary pressure to which all adversaries—state and non-state—have responded, and that this response is shaping new approaches to war.

Age and size at maturity have been an object of interest to humans since the domestication of animals and plants, for one of the objectives of domestication was to produce an organism that grew fast and matured early at a large size. Selection was also practiced to produce animals that could be used for such purposes as hunting and portaging, and to produce products for pleasure alone, as seen in the many ornamental varieties of dogs, cats, goldfish, pigeons, and plants. All of these instances demonstrate that age and size at maturity are traits that are relatively easily molded by artificial selection and, by extension, natural selection. Historically, artificial selection experiments were concerned not with the evolution of age and size at maturity in natural populations but with the production of economically more valuable plants and animals. Recently, there has been a substantial increase in the quantitative genetic analysis of nondomesticated organisms, which has shown that, with respect to morphological traits such as adult size, there is typically abundant additive genetic variance, with heritabilities averaging approximately 0.4 (reviewed in Roff 1997). Life history traits, such as the age at maturity, show, on average, lower heritabilities (approx. 0.26) but still enough for rapid evolutionary change. Quantitative genetic analyses have shown that age and size at maturity can evolve, but the most significant advances in our understanding of the factors favoring particular age at maturity/body size combinations are due to mathematical models predicated upon the assumption that selection maximizes some fitness measure such as the rate of increase, r. In a paper entitled “Adaptive Significance of Large Size and Long Life of the Chaetognath Sagitta elegans in the Arctic,” McLaren (1966) produced a seminal analysis in which he incorporated all the important elements that have appeared in subsequent analyses of the evolution of age and size at maturity. Specifically, McLaren attempted to take into account the trade-offs produced by increased fecundity being bought at the expense of delayed maturity and increased mortality. In this chapter, I shall primarily consider analyses that have followed in McLaren’s footsteps.

When Charles Darwin and Alfred Russell Wallace proposed their theory of evolution by natural selection, the concepts of evolution and speciation were not new. Darwin introduced The Origin with “An Historical Sketch,” in which he summarized the work of 34 previous authors who had speculated on evolution and the origin of species. What was new about Darwin and Wallace’s proposition was natural selection as the mechanism of evolutionary change. Darwin further proposed that natural selection was a unifying process that accounts for adaptation, for speciation, and hence for the diversity of life on earth. Darwin and Wallace proposed natural selection as a process that caused evolution. Adaptations are features of organisms that were shaped by this process. The modern version of Darwin and Wallace’s theory allows for other agents of evolution, such as genetic drift, migration, and mutation, but adaptation remains a product of natural selection alone. The virtue of their proposal is that it allows us to develop testable hypotheses about cause-and-effect relationships between features of the environment and presumed adaptations. Natural selection immediately became a source of controversy, although the nature of the controversy has shifted over time. First, there has been considerable debate about the definition of adaptation (e.g., Reeve and Sherman 1993). We do not wish to add to or summarize this debate because we feel that Darwin got it right the first time. Besides defining a cause-and-effect relationship between selection and adaptation, Darwin emphasized that we should not expect organisms to be perfectly adapted to their environment. In fact, this emphasis was a large component of his argument against divine creation. For example, Darwin recognized, through his experience with artificial selection, that different aspects of morphology were in some way “tied” to one another so that selection on one trait would cause correlated changes in others that were not necessarily adaptive. He also recognized that organisms were subject to constraints that might limit their ability to adapt. Finally, he argued that how organisms evolved was a function of their history, so that the response to selection on the same trait would vary among lineages. A more telling criticism considers the application of cause-and-effect reasoning to the interpretation of features of organisms as adaptations, and hence to the empirical study of adaptation.

This chapter first examines H. P. Grice's theory of conversation. Grice argued that human conversations generally revolve around a presumption of a common purpose. We sometimes may be deluded in thinking that such a shared purpose exists but the supposition is required to make us willing to participate. The purpose may be obvious, or frivolous, extremely serious, or horrific. The chapter then discusses what Grice's theory might be able to tell us about the role of conversation as one place where nascent conventions may be born and where they are subjected to an analogue of artificial selection. After explaining what allows conversation to serve as a tool for managing other kinds of culture, the chapter concludes by considering how these capabilities could have given rise to the very complex culture we live in today.

This chapter examines how nineteenth-century philosophers from William Paley and Charles Darwin to John S. Mill and William Whewell described and debated the relations between art and science as well as practice and theory. Offering close readings of Paley’s Natural Theology and of various passages from Charles Darwin’s work on breeding and gardening, the chapter distinguishes between two conceptions of art in the sense of skilful practice: art as guided by knowledge and different from nature on the one hand and art as productive of knowledge as well as continuous with an evolving nature on the other. As the chapter argues, these two notions of art played a key role in a controversy between John S. Mill and William Whewell that was carried out, between 1840 and 1872, through successive editions of their published works. Engaging closely with the style and spirit in which this debate was conducted, the chapter shows that Mill and Whewell argued from radically different conceptions of what ‘science’ means. As a result, they disagreed, for instance, about the very question of what constitutes a logical form of argument or proof.

Synthetic biology is often described as a project that applies rational design methods to the organic world. Although humans have influenced organic lineages in many ways, it is nonetheless reasonable to place synthetic biology towards one end of a continuum between purely ‘blind’ processes of organic modification and wholly rational, design-led processes. An example from evolutionary electronics illustrates some constraints imposed by the rational design methodology itself. These constraints reinforce the limitations of the synthetic biology ideal, limitations often freely acknowledged by synthetic biology’s own practitioners. The synthetic biology methodology reflects a series of constraints imposed on finite human designers who wish, as far as is practicable, to communicate with each other and to intervene in nature in reasonably targeted and well-understood ways. This is better understood as indicating an underlying awareness of human limitations, rather than as expressing an objectionable impulse to master nature.

The domestic dog, Canis familiaris, presents an unusual case study for the consideration of captivity of nonhuman animals. On one level, the captivity of the species is discussable: by virtue of the species’ domestication, through thousands of years of artificial selection, the species is obligatorily attached to, or held captive by, their domesticators, humans. On another level, one can also consider the captivity of the individual, as seen in pet-keeping practices that bear on the social, sexual, and mental life of dogs. In this chapter these captivities are considered, as well as the infringements captivity has wrought on the animal’s body, cognition, and Umwelt. The notion of "freedom" for dogs is also discussed.

This chapter examines whether products of nature and living organisms such as plants can be considered manufactures or inventions that are patentable. It first discusses the relevant provisions of the Plant Patent Act of 1930, particularly with respect to plant breeding techniques such as artificial selection. It then turns to court decisions on the question of what it meant to invent a plant. It also explores how to distinguish between products of nature and products of human ingenuity for the purposes of the 1930 Act and how the respective contributions of nature and human ingenuity should be delimited. Finally, the chapter looks at the analogy between plant breeding and invention and the theory of creative replication.

This chapter applies the evolutionary concepts explained in Chapter 2 to a series of case studies of nonstate adversaries. It explores how specific nonstate adversaries have adapted and evolved since 1993; these include Al Qaeda, Islamic State, Al Qaeda’s Syrian affiliate Hayat Tahrir al-Sham, and the Lebanese Shi’a group Hezbollah. The chapter shows that each of these irregular armed groups, despite differences of ideology, origin, operating environment and structure, are all responding in their own ways to a fitness landscape created by Western dominance of a particular, narrow, technology-centric form of warfare. Their patterns of adaptation indicate the ways in which evolutionary processes identified in the previous chapter have played out in practice.