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This chapter discusses the epidemiology of tuberculosis from the perspective of population biology. The central concept of population biology with reference to TB control is that a population of organisms (here TB cases) cannot persist if the generation case reproduction number, R, is maintained below the critical value of one. Hence, if one case of TB always generates less than one secondary case on average (R < 1), then Mycobacterium tuberculosis is doomed to extinction. The chapter first provides an overview of the empirical epidemiology of TB before introducing a family of dynamic models to investigate the key questions about TB epidemiology and control. The models are used to assess TB transmission, reinfection and relapse, variation in infectiousness, rise and fall of TB during the industrial revolution, and the characteristics of TB epidemics.

This chapter draws together the epidemiological insights that come from population biology and considers the context in which tuberculosis remains a “social disease” in the early twenty-first century. The distinctive contribution of population biology is to range quantitatively across demography, ecology, epidemiology, environmental science, and evolution. Widening the horizon will bring into view a greater range of options for tackling TB in the post-2015 era of health and sustainable development. The chapter argues that the striking gap between the actual and potential impact of drug treatment underscores the need to find ways to boost the demand for—and supply of—health services. Much emphasis has been placed on developing new technology for TB control; too little attention has been paid to the design of health and social systems that can make best use of technology.

This chapter provides an empirical account of the evolutionary and epidemiological history of tuberculosis in populations around the world. Much has happened in the population biology of TB since 1960, and despite the development of highly efficacious drug therapy to prevent and cure TB, the disease remains the largest cause of death from a single, curable infectious agent. The challenge we face in the twenty-first century is to control—and ultimately eliminate—a pathogen that has inhabited human populations for tens of thousands and possibly millions of years. To begin to understand how TB control and elimination could be achieved, this chapter defines the problem. It describes the essential characteristics of Mycobacterium tuberculosis and the collection of diseases it causes, its origins and distribution in human populations, the dominant trends through time, and the burden of disease today.

This chapter examines the dual epidemic of tuberculosis and HIV/AIDS. There have been some major successes in the control of both HIV/AIDS and TB. The discovery and widespread use of antiretroviral therapy (ART) is among the greatest advances in public health during the past thirty years. The rise of TB cases in Africa and elsewhere and on the discovery and implementation of control measures raise a series of questions about the population biology of TB linked to HIV/AIDS. The chapter first provides an overview of HIV infection as a risk factor for TB before discussing the global epidemiology of TB linked to HIV/AIDS. It then describes the anatomy of a TB-HIV epidemic, along with TB control in the presence of HIV. In particular, it considers ART and isoniazid preventive therapy. The chapter concludes with the argument that the DOTS strategy is necessary but not sufficient for TB–HIV control.

This book has argued for the reality of a class of biological entities that have a hard time finding their place in a theory of evolution based on genetics and population biology. These entities, or developmental types, include cell types, homologs, and body plans. The book has also provided examples that already have empirical data to see whether such ideas are contradicted by known facts about certain well-studied organ systems, like limbs, skin appendages, and flowers. This concluding chapter summarizes the book's central claims about homology, characters and character identity, and cooperativity in gene regulatory networks. It also discusses some of the lessons derived from reviewing the literature on these paradigms of devo-evo research as well as the challenges inherent in this perspective of developmental evolution.

This book has described a comprehensive framework for thinking about the geography and ecology of species distributions, arguing that such a framework is critical to further progress in the field of ecological niches and distributions. To develop this framework, traditional concepts in ecology have been radically reworked. In this conclusion, some of the challenges for future work regarding ecological niche modeling are discussed, such as fully integrating the BAM diagram with central concepts of population biology and statistical theory; clarifying the notion of niche conservatism versus niche evolution as regards scenopoetic versus bionomic environmental dimensions; and improving the link between correlational and mechanistic approaches to estimating and understanding ecological niches. The book argues that careful conceptual thinking must be combined with detailed empirical exploration in order to address each of these challenges.

This chapter discusses the population biology and ecological genetics of native species within California grasslands, providing many important insights into the processes of microevolutionary change in plant populations. It describes basic population genetics concepts, ranging from co-adapted gene complexes to evolution of phenotypic plasticity.

This chapter explores large-scale patterns of relative diversity across families of stoneflies. It examines three aspects of stonefly ecology including shredding, predation, and population biology with special attention to scale. The chapter highlights the existence of major structural differences in the macroecology of stoneflies in North America and the Holarctic, and proposes a research agenda in stonefly ecology emphasizing collaboration and a geographical perspective.

This chapter argues that the environmental stressors acting upon populations, especially those stressors of anthropogenic origin, can be better divided into the following three evils: habitat destruction, habitat fragmentation, and habitat degradation. Different species, with differing susceptibilities to extinction, should react to these environmental stressors in various ways depending upon their ecological differences, especially in demographic characteristics and population structures. Amphibians exhibit a variety of natural history and life history strategies, and this concept must apply as much to them as to the organisms upon which it was based. A classic problem in animal demographics and population biology is how populations of small animals (rodents, particularly lemmings, in the classic case) fluctuate in size. To understand amphibian population declines, this chapter examines amphibian persistence, extinction, and population increase. It then places these in the context of habitat destruction, habitat fragmentation, and habitat degradation.

This chapter reviews the basic aspects of anole population biology and life history and the role of anoles in the ecosystem, discussing reproduction, growth, dispersal, life span and survival rates, predation, parasites, population density and constancy, and diet. In some cases, such as diet, considerable diversity exists within and among anole species. The chapter explores this diversity, explaining its ecological and evolutionary significance.

This chapter shows how dispersal can profoundly influence many aspects of population biology. Dispersal itself can evolve since adaptive differences in dispersal are common among genotypes, populations, or species. Dispersal is discussed here as a complex syndrome of traits, consisting of the integrated expression of many morphological, physiological, and behavioural aspects of dispersal as well as other life-history traits. Important issues in dispersal genetics are discussed here, including the genetic basis of variation in individual traits that contribute to the capacity to disperse and the overall degree of dispersal movement per se, and the genetic mechanisms that coordinate the adaptive expression of multiple dispersal traits with other organismal features. Advancements in the field of dispersal genetics will also be discussed in detail in this chapter.

This chapter discusses ‘epidemiology’, which in medical literature refers to the field that seeks to identify key correlates for a particular disease. In this book, however, it is the study of host–parasite population dynamics as a branch of population biology and population genetics. Beginning with the Swiss mathematician Daniel Bernoulli, who used a mathematical model to analyse the dynamics of a small-pox epidemic in Paris, epidemiology provides a great help to the study of evolutionary parasitology. The classical Nicholson-Bailey model is one example of an epidemiology model that analyses host–parasitoid systems. The chapter examines other models, such as SIR-models, in order to further analyse the epidemiology of hosts and their microparasites. It also talks about the epidemiology of vectored microparasites, like malaria, which can also similarly be analysed with modified SIR-models such as the classical Ross-Macdonald model.

This chapter focuses on the domestication of dogs. It discusses the human perspective on dog domestication; zooarchaeological and phylogenetic models of dog domestication; and dog domestication from the point of view of population biology.

After 600 years of persecution, during which dramatic population fluctuations occurred, common buzzards are increasing in abundance and recolonizing most of lowland UK. But recovery is bringing them to the heart of a controversy. Once again, game-managers and poultry farmers blame buzzards for killing stock and thus harming livelihoods. To better understand buzzard biology and assess their impact on wildlife and domestic stock, field data and well-established and innovative modelling techniques were used. It was noted that phylopatry resulted in a naturally slow rate of buzzard population expansion, while habitat availability now limits population abundance. The impact of buzzard predations on released pheasants was found be variable but typically small, and it was also found that high predation can be reduced with simple pen management measures. Licensed translocation of ‘problem’ buzzards may also be an option, but only if accompanied by improvements in management to avert re-colonizing buzzards from also developing a livelihood-harming diet. The worry is, however, that concern about translocation of raptors risks diverting public opinion from the more serious issues of poor land use and climate change.

This chapter discusses the influence of environmental factors towards social structure and social behaviour. It looks into the variety of impacts of human-induced environmental changes on sociality and studies the demographic consequences on population biology. It analyses intraspecific and interspecific variation in sociality in identifying key environmental drivers of demography. It enumerates some of the ways that social behaviour and social structure are dependent upon the distribution and abundance of resources and other environmental factors. It presents individual based-models that allow prediction of demographic consequences of anthropogenic factors such as climate change and habitat alteration, and also to predict the consequences of anthropogenic change on a variety of animals.

This chapter presents a critique of Neo-Darwinism and the case for Holistic Darwinism. It discusses the realization of the founding fathers of modern genetics and population biology concerning the flaws of Neo-Darwinism, particularly in relation to group selection theory. These attacks on group selection theory began with William D. Hamilton's The Genetical Evolution of Social Behavior and was fully elaborated in George C. Williams' Adaptation and Natural Selection. This chapter also highlights the key features of Holistic Darwinism and its theoretical superiority over Neo-Darwinism.