Search Results

Competition and coadaptation

Dale H. Clayton, Sarah E. Bush, and Kevin P. Johnson

in Coevolution of Life on Hosts: Integrating Ecology and History

The preceding chapters of the book focused on interactions between hosts and parasites. This chapter focuses on competitive interactions between different species of parasites, and the role of the ... More

The preceding chapters of the book focused on interactions between hosts and parasites. This chapter focuses on competitive interactions between different species of parasites, and the role of the host in mediating those interactions. Parasites do not live in isolation, but are members of diverse parasite communities that share hosts. While no individual harbors all parasites known from that host species, most individuals support more than one species of parasite at a time. The presence of a given parasite species can have a negative effect on other parasites due to competition for limiting resources in or on the shared host. Even parasites that exploit very different parts of a host's body may compete, because each host individual is ultimately a single resource. Interspecific competition can lead to the coadaptation of traits that reduce the intensity of competition. Thus, in addition to coevolving with the host species, parasites coevolve with other parasites that share that same host species. The chapter begins by considering competition between parasite species, in general. It then provides a more detailed overview of competition between species of lice.Less

The Finite Planet

Frank H. T. Rhodes

in Earth: A Tenant's Manual

This chapter examines the Earth's finitude of space and resources, noting that land areas cannot so much be changed or expanded upon as it can be reused or replaced. Although there are the ... More

This chapter examines the Earth's finitude of space and resources, noting that land areas cannot so much be changed or expanded upon as it can be reused or replaced. Although there are the possibilities of colonizing other areas of the solar system, the chapter focuses largely on the planet Earth and its own finite resources. It emphasizes the need for restraint and resourcefulness on a planet with rather daunting limits, especially in the face of the ever-growing human population. Moreover, given their population and their penchant for consumption, the human species has invariably created most of the problems that plague the Earth today. Responsible tenancy on Earth thus becomes a challenge, though not an impossible one—human knowledge is, unlike the Earth's resources, unlimited in scope.Less

The Sustainable Planet

Frank H. T. Rhodes

in Earth: A Tenant's Manual

This chapter provides an overview of sustainability and how it can be maintained in a world of limited resources. It posits some definitions of the term “sustainability,” noting that any workable ... More

This chapter provides an overview of sustainability and how it can be maintained in a world of limited resources. It posits some definitions of the term “sustainability,” noting that any workable definition thereof requires some combination of ethical, social, economic, environmental, and operational components. Two questions thus arise in obtaining a definition of sustainability: one of equity, the other of costs; and the two are closely related. The chapter then turns to the issue of defining a list of basic requirements for human survival, before turning to the larger issue of the Earth's “carrying capacity,” so to speak, and how it involves social, ethical, and economic as well as physical and biological considerations.Less

Priority setting in health systems

David J. Hunter

in The health debate: Policy & Politics in the Twenty-First Century

This chapter examines rationing and priority setting in the health care sector. It investigates why rationing is no longer much discussed in contemporary health policy debates, while it was on every ... More

This chapter examines rationing and priority setting in the health care sector. It investigates why rationing is no longer much discussed in contemporary health policy debates, while it was on every policy maker's lips just a decade ago. It explores how the issues of rationing and priority setting are being addressed in health systems that continue to have to manage growing demand with limited resources.Less

Reproductive contests and the evolution of extreme weaponry

Douglas J. Emlen

in The Evolution of Insect Mating Systems

Many insect species face intense reproductive competition, with males battling rival males for opportunities to mate with females. In some lineages the intensity of reproductive competition has led ... More

Many insect species face intense reproductive competition, with males battling rival males for opportunities to mate with females. In some lineages the intensity of reproductive competition has led to the evolution of extravagant weapons—disproportionately large mandibles, antlers, horns, or legs. Comparison of the behaviours and natural histories of heavily armed species with related species lacking big weapons hints at the ecological circumstances likely shaping the evolution of extreme weapon sizes. Escalated weapon evolution appears most likely when insects depend on limiting resources that are localized and economically defensible, and when fights over these resources unfold on, or in, substrates that restrict access to guarding males, structuring male—male encounters so that they tend to occur as a succession of duels, rather than multi-male scrambles. This combination of (1) intense reproductive competition, (2) limiting, localized resources, and (3) one-on-one contests, appears a potent formula for rapid evolution of extraordinary weapon sizesLess

Interspecific Interactions II: Competition and Mutualism

Michael J. Fogarty and Jeremy S. Collie

in Fishery Ecosystem Dynamics

Competition and mutualism are important forms of biotic interaction in aquatic communities. Quantification of the population and community-level effects of these interactions has historically been ... More

Competition and mutualism are important forms of biotic interaction in aquatic communities. Quantification of the population and community-level effects of these interactions has historically been less common in fisheries analyses than predation. In part, this reflects the difficulties in conducting controlled experiments for larger-bodied organisms in aquatic environments. Documenting competition entails not only identifying patterns of shared resource use but evidence that these resources are limiting. Inferences concerning competitive interactions in non-experimental settings may be possible if histories of population change for putative competitors are available and quantifiable interventions involving the addition of a species (through deliberate or inadvertent introductions) or a differential reduction in abundance of the species through harvesting is undertaken. Care must be taken to account for other changes in the environment in these uncontrolled quasi-experiments. Mutualistic interactions are widely recognized in aquatic ecosystems but far less commonly quantified than competition.Less

Policing Relief

in Miss Cutler & the Case of the Resurrected Horse: Social Work and the Story of Poverty in America, Australia, and Britain

This chapter discusses the social work of relief agencies in Oregon which included the Public Welfare Bureau, the Associated Charities, and the Child Welfare Commission (CWC). The stories of Oregon ... More

This chapter discusses the social work of relief agencies in Oregon which included the Public Welfare Bureau, the Associated Charities, and the Child Welfare Commission (CWC). The stories of Oregon social workers reveal a mix of public and private relief that characterized many Americans' experience of charity and social work before 1930. They also provide evidence of the poor communication, overwork, and limited resources similar to that which had long plagued the administration of public relief in America.Less

The Governance Ideal

M. A. Thomas

in Govern Like Us: U.S. Expectations of Poor Countries

This chapter explores the Western governance agenda and how the emergence of the current conception of governance in a handful of countries in the mid-twentieth century was concomitant with and ... More

This chapter explores the Western governance agenda and how the emergence of the current conception of governance in a handful of countries in the mid-twentieth century was concomitant with and dependent on increased government revenue. Notably, there is a visible correlation between increased revenue and the growth of the public sector, as increased revenue can provide the resources needed to effect certain laws and statutes, as well as to provide public goods and services. Poor governments are at a handicap due to their limited resources, and are often forced to engage in practices that are considered illegal in other countries because they cannot afford better alternatives. Thus, they should not be expected to address issues in the same manner as rich liberal democracies, and held against a moral standard defined by the latter.Less

The Office of the United Nations High Commissioner for Human Rights: Mapping the Evolution of the Right to Health

Gillian MacNaughton and Mariah McGill

in Human Rights in Global Health: Rights-Based Governance for a Globalizing World

For over two decades, the Office of the UN High Commissioner for Human Rights (OHCHR) has taken a leading role in promoting human rights globally by building the capacity of people to claim their ... More

For over two decades, the Office of the UN High Commissioner for Human Rights (OHCHR) has taken a leading role in promoting human rights globally by building the capacity of people to claim their rights and governments to fulfill their obligations. This chapter examines the extent to which the right to health has evolved in the work of the OHCHR since 1994, drawing on archival records of OHCHR publications and initiatives, as well as interviews with OHCHR staff and external experts on the right to health. Analyzing this history, the chapter then points to factors that have facilitated or inhibited the mainstreaming of the right to health within the OHCHR, including (1) an increasing acceptance of economic and social rights as real human rights, (2) right-to-health champions among the leadership, (3) limited capacity and resources, and (4) challenges in moving beyond conceptualization to implementation of the right to health.Less