Life on Earth

9 Key excerpts on "Life on Earth"

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  Physical Geography

  • James Petersen, Dorothy Sack, Robert Gabler(Authors)
  • 2016(Publication Date)
  • Cengage Learning EMEA

    (Publisher)

  3 1 PLANET EARTH IS HOME TO a large and complex set of living organisms, including humans. Earth’s surface is our natural habitat, providing us with air, water, nutrients, and shelter. Earth also receives enough sunlight to maintain livable temperatures and to power food production by plants through photosynthesis. Surrounded by the emptiness of space, Life on Earth is dependent on the planet’s self-contained natural resources that are extensive, but not limitless. Only recently in the history of human life have we been able to view Earth in its entirety from space, giving us a fresh perspective on characteristics of the ocean, atmosphere, land masses, and natural vegetation. In addition to being able to see the physical Earth as a whole, technological advances in communication, transportation, and information sciences over the last several decades have led to an increasingly global social perspective. These developments, combined with population growth, make the world seem smaller, and have helped heighten awareness of the finite nature of Earth, its environments, and its resources. OUTLINE The Study of Geography Physical Geography Geographic Tools and Technology Major Perspectives in Physical Geography Spatial Science Perspective Geography’s Spatial Science Perspective: Natural Regions Physical Science Perspective Environmental Science Perspective Geography’s Environmental Science Perspective: Human–Environment Interactions Using Models and Systems Systems Analysis Open and Closed Systems Equilibrium in Earth Systems Physical Geography and You OBJECTIVES WHEN YOU COMPLETE THIS CHAPTER YOU SHOULD BE ABLE TO: ■ 1.1 Explain why physical geography examines both the natural world and human interaction with the natural world. ■ 1.2 Discuss important ways in which geographic information and techniques are useful in different careers. ■ 1.3 Describe the three major perspectives of physical geography: spatial science, physical science, and environmental science.

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  Biogeography

  A Study of Plants in the Ecosphere

  • Joy Tivy(Author)
  • 2018(Publication Date)
  • Routledge

    (Publisher)

  _______ Chapter _______

   

   1

   

  Introduction

       

  Biogeography, as the term indicates, is both a biological and a geographical science. Its ‘field of study’ is the biologically inhabited part of the lithosphere, atmosphere and hydrosphere – or, as it has become known – the biosphere . Its subject-matter covers the multitudinous forms of plant and animal life which inhabit this relatively shallow but densely populated zone, as well as the complex biological processes which control their activities. The approach to, and aim of, the subject is geographical in so far as it is primarily concerned with the distribution (together with the causes and implications thereof) of organisms and biological processes. However, although this ‘field of study’ is shared by, and is common to, both biology and geography it is not the exclusive preserve of either of these two sciences. By its very character, biogeography is situated at, and overlaps the boundaries of, a great number of other disciplines. The geologist, climatologist, pedologist, geomorphologist as well as the botanist, zoologist, geneticist and geographer (to mention but a few) all ‘cultivate’ or ‘crop’ as the case may be, particular parts of this very large and varied field; and in doing so they are, to a greater or lesser extent, essential to, as well as being dependent on, an understanding of biogeography. As a result, the approach to – or concept of – biogeography is in large measure determined by the training, interest and objectives of the particular student.

  The geographer’s interest tends to focus on (to be organised around) the spatial variation of two basic characteristics or processes, rather than on any particular components of the biosphere. The first is the intimate interrelationship between the organic and inorganic elements of the earth’s environment; the character of the biosphere is primarily a product of the continual interaction or interchange between the lithosphere and the atmosphere. The second is the reciprocal relationship between humans and the biosphere. On the one hand the latter provides the vital link between man and his physical environment; and despite the advances of modern science and technology man is still, whether he realises or likes it, completely dependent on the biosphere for his food. On the other hand, because of an ability, greater than that possessed by any other form of life, to exploit organic resources he is not only an integral part of the biosphere but is now the ecologically dominant organism in it. The significance of biogeography is particularly well expressed by the ecologist M.G. Lemée (1967: 4) in Précis de Biogégraphie

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  Biogeography

  Introduction to Space, Time, and Life

  • Glen MacDonald(Author)
  • 2015(Publication Date)
  • Wiley

    (Publisher)

  PART SPACE AND LIFE I This page intentionally left blank 9 CHAPTER SOME BASICS 2 Biogeography is a very broad science, and biogeographers are a highly diverse group of scientists. This multidisciplinary scope is one of the most satisfying aspects of biogeography–and one of the most challenging. Biology, geography, and geology all contribute concepts, specialized vocabularies, and ways of classi- fying information that are important to biogeography. In order to understand and appreciate the science of biogeography, we must therefore have some knowledge of its foundations in these other sciences. Before we get down to the business of biogeography, we will review some key concepts from these associated disci- plines. In this chapter, we will concentrate on aspects of biology and physical geography that are fundamental to biogeography. Later in this book we will dis- cuss some concepts from geology that are also important to biogeography. Much of the material that we cover here will be familiar to anyone who has taken intro- ductory courses in biology and physical geography. However, even for those with such a background, a little review won’t hurt. BIOLOGY AND THE HIERARCHIES OF LIFE Biology can be defined as the science of life and all of its phenomena. Life on Earth includes millions of different types of organisms, ranging from viruses to whales. The study of any of these organisms could include examination of myriad phenomena, from biochemical reactions to social behavior. It is clear that biolo- gists face a daunting challenge! The science of biology tackles this immense task by breaking it down into smaller components that can be studied individually. One way to categorize and organize the constituent units of a large entity is to develop a hierarchy.A hierarchy is a system of organization in which components are ordered by rank.

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  The Science and Technology of the Environment

  • James G. Speight(Author)
  • 2022(Publication Date)
  • Apple Academic Press

    (Publisher)

  PART I Definitions and Resources Passage contains an image

  Chapter 1 History, Definitions, and Terminology

  1.1 Introduction

  The environment provides the life support system of the Earth and is the source of various resources which are essential for life. Different components of environment interact within themselves and with living organisms present over there. These interactions have great bearing on the survival of organisms (Jazib, 2018 ).

  The air (the atmosphere), the water (the aquasphere), and the land (the geosphere) are the major parts of the environment and Life on Earth depends on these interrelated components of the environment. Any disturbance to any of these components will affect the entire environmental system. Human intervention in the natural environment has already caused a great deal of changes to the system although natural causes-often ignored by some observers also contribute to climate change (Speight, 2020 ). Both natural and anthropogenic effects can cause changes to the living organisms (flora and fauna) in the environment.

  By way of definition and description, a living organism within the environment is a product of the genetic makeup (genotype) of the organism and of the environment in which the organism lives (phenotype). Also, it is an environment which shapes the nature, distribution, and prosperity of a population. And this is where environmental science and environmental engineering play a role.

  Environmental science is an interdisciplinary field that integrates the physical sciences and the biological sciences such as (alphabetically) atmospheric science, biology, chemistry, ecology, geology, mineralogy, limnology, oceanography, soil science, and zoology to the study of the environment, and the solution of environmental problems. Similarly, environmental engineering integrates the various engineering disciples to the development of processes and infrastructure for the supply of water, the disposal of waste, and the control of pollution. The activities of environmental scientists and engineers protect public health and well-being by preventing disease transmission, and they preserve the quality of the environment by averting the contamination and degradation of air, water, and land.

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  Physical Geography

  Great Systems and Global Environments

  • William M. Marsh, Martin M. Kaufman(Authors)
  • 2012(Publication Date)
  • Cambridge University Press

    (Publisher)

  This chapter opens with a brief look at the biosphere as a physical component of the landscape and oceans and then goes on to examine Earth’s bio-energy system. Scientists refer to this system as an ecosystem and all life from bacteria and flies to humans and redwoods is inextricably woven into ecosystems. What drives ecosystems and how do plants convert the energy and matter that fuels them into organic energy and how does that energy get passed along to other organisms? And to make things truly geographical, we must examine how the work of ecosystems is distributed over the globe, and how it all relates to geographic conditions of the atmosphere, land, and sea, such as the distribution of heat and moisture. Finally, where do we humans and the agricultural systems we have put together fit into the global ecosystem? Chapter Overview 9 Earth as an Ecosystem: Energy, Food, and Life Introduction Earth’s biological system has been developing for over 3 billion years. It began in the sea with simple, single-celled organisms and evolved into a vast network of plants, animals, and microorganisms that today occupies the entire planet. We call this network of life the biosphere, and although it can seem massive when we stand in a forest or dive into the ocean, it is actually quite thin and tenuous compared to the lithosphere, hydrosphere, and atmosphere. Yet the biosphere is central to Earth’s geographic character for, among other things, it is instrumental in shaping soil, climate, hydrology, and the physical character of most landscapes. The built environment of humans is itself a product of the biosphere because, like a coral reef or a termite colony, it too is constructed by an organism. What enabled the biosphere to grow, diversify, and spread over the planet? Was it evolution, the process by which life changes and adapts over time? Part indeed can be attributed to evolution, especially the diversification of life and its occupation of new environments.

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  Eco-facts and Eco-fiction

  Understanding the Environmental Debate

  • William H. Baarschers(Author)
  • 2013(Publication Date)
  • Routledge

    (Publisher)

  All these interactions are interdependent, and together they form one large interwoven system, an ecosystem. Since the whole planet with its many species is so large and complex a system, subdivision into smaller areas of study, localized ecosystems, is common. Part of ecology is of a descriptive nature and another part consists of the complex mathematics of population dynamics. Several pioneers of the mathematics of chaos came from the field of mathematical ecology, or geographical ecology as it is also called. 26 Within the biology context, ecology consists of many parts, indicating a great deal of specialization. Smaller study compartments contain quite specific, limited aspects of the relationships between organisms and their environment. Some biologists deal with ecology as it relates to different kinds of landscapes, or landscape types, such as grassland ecology, mountain ecology or estuarine ecology. Others study the way specific animals relate to their environment. They specialize in honeybee ecology or earthworm ecology. On a larger scale highlands ecology or California ecology, for example, have to do with geographical areas, highway design, and city planning. Ecology, in all its widely varying forms, has become a well-established scientific discipline among the traditional sciences. A useful general ecology text at the introductory level is Nisbet's Leaving Eden. 27 As part or our relationships with other organisms, humans greatly influence the environment. It is only logical that ecological issues and environmental issues became so closely connected. The terms also started to develop a much wider meaning. For example, several dictionaries define the science of anthropology as a study of humans and their relationship with their surroundings

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  Greening the College Curriculum

  A Guide To Environmental Teaching In The Liberal Arts

  • Jonathan Collett, Stephen Karakashian, Jonathan Collett, Stephen Karakashian(Authors)
  • 2013(Publication Date)
  • Island Press

    (Publisher)

  The approach of geographers to the study of environmental change emphasizes spatial pattern, a large scale of inquiry (over space and time), and the integration of social and natural sciences. Geographers typically conduct research at the level of landscape or region; for example, considering land use patterns and their impact on vegetation in a drainage basin or watershed. Recently, geographers have begun working at much broader scales. Such a study is under way in Mexico, where Liverman (1990) is investigating the capacity of small-scale farmers to cope with climatic change over several decades. Research elsewhere documents local adaptation in land management upon elevated exposure to storms, oil spills, flooding, and other forms of environmental risk (Kates and Burton 1986).

  While geography as a discipline encompasses a broad realm of inquiry, geographers as individuals tend to specialize in either human or physical studies, often borrowing methods of analysis from other disciplines. Geographers traditionally break the study of human transformation of the biosphere into four fields: (1) regional studies, (2) people—environ-ment studies, (3) environmental processes and resources, and (4) spatial analysis.

  Regional Studies

  Geographers working in this tradition address conservation issues relevant to a particular place. A regional focus allows students to understand how the physical characteristics and social history of a place have led to a unique land use system. Students may draw on this insight to evaluate the sustainability of a land use system and to predict how changing external and internal factors may result in the transformation or degradation of a landscape (Leighly 1969). For example, many Latin Americanist geographers examine how deforestation in the Amazon is driven by distinctive regional characteristics such as land tenure patterns, demographic features, government policies, and agricultural and economic systems (Hecht and Cockburn 1989; Smith 1982).

  People—Environment Studies

  Within this broad focus, geographers explore the relationship between society and nature in terms of causes and consequences. The justification for environmental conservation is likely to vary dramatically according to a society’s own view of its relationship with nature. Ancient writers such as Hippocrates, Ptolemy, and Strabo expressed a profound desire to define the human role in the natural world. Since then, many philosophies have developed, ranging from the Christian doctrine of defining man as master of nature (Glacken 1956) (see Chapter 11, Religion), to Romantic/Arcadian ideas of humanity in harmony with nature (O’Riordan 1981) (see Chapter 7, Literature), to deterministic theories akin to social Darwinism that individual and social characteristics are formed by the physical environment (Semple 1911), to notions that human choice is influenced primarily by cultural and historical factors (Lewthwaite 1966). (These latter viewpoints are discussed fully in Chapter 2, Anthropology.) Accordingly, the aim of conservation will vary in terms of what type of human intervention in ecosystems a given society considers desirable.

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  An Introduction to Population Geographies

  Lives Across Space

  • Holly R. Barcus, Keith Halfacree(Authors)
  • 2017(Publication Date)
  • Routledge

    (Publisher)

  And finally but critically, these circumstances are, to greater or lesser degrees, ever-changing through a life, through their embodiment in a life course (Chapter 2). In short, life experiences are always relational in respect of spaces and individual lives. Understanding and explaining the population geographies of births, deaths and population movement requires taking into account a wide array of economic, social, cultural, political and environmental processes. These are reflected in, for example, resource conflict, everyday living environments, differences in health and well-being, levels of poverty and inequality, and relationships formed both within and between peoples and countries. These processes both shape the population characteristics of any particular society and its individual members, and are in turn shaped by them. Thus, studying Population Geography requires core demographic indicators such as births, deaths and migrations not to be thought of in isolation but examined through their entanglements with the full panoply of diverse processes that construct everyday life. This is, of course, no mean feat but reflects both the challenge and potential sense of achievement to be had in explaining what the present authors are calling lives across space. Next, though, an historical account of Population Geography up to the present day is outlined. This both establishes a fuller academic context for the rest of the book and demonstrates how an expanded notion of Population Geography is congruent with recent critical reflection within the sub-discipline. Table 1.1 Comparative infant mortality rates Infant mortality

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  Reinvention of Australasian Biogeography

  Reform, Revolt and Rebellion

  • Malte C. Ebach, Malte Ebach(Authors)
  • 2017(Publication Date)
  • CSIRO PUBLISHING

    (Publisher)

  3 In order to understand what biogeography is, we need to see how biogeography is done.

  The search for natural biotic areas

  Unless you are reading this in outer space, you are currently in – or driving, riding, flying or sailing over – a natural biogeographic region. The region is defined by the organisms that inhabit it – the biota – which have been formed by millions of years of evolutionary, geographical, geological and climatic processes. This includes the barriers that encapsulate the biota, isolating it from other biota. Over time, these biota diversify and become endemic to areas in which they live. If you are standing in a plain near a troop of kangaroos, for example, you are most likely in Australia. But things get moved around. For instance, you may also be standing in a kangaroo enclosure in a zoo. Biogeography is never clear cut; rather it is messy. Animal and plants tend to move around, either naturally or by human-assisted means, such as the introduction of the cane toad in Australia or eucalypts in Spain. Identifying which organisms are part of a natural area is incredibly difficult for several reasons. First, not many people work on more than one taxonomic group. A single taxonomic group does not make a biota. Next is the problem of whether your taxonomic group is actually endemic. It might be introduced or naturally cosmopolitan. The biggest hurdle, however, is determining the relationships between the species and genera under study. Without these, you have no independent source of information about the relationships of your areas. The only way to find out what these relationships are is to find the relationships between the morphological or molecular characteristics of your organisms. For much of the 18th, 19th and 20th centuries, this type of information was unavailable. Not until the 1970s were we able to investigate morphological and genetic relationships using numerical methods. Before then, natural areas were assumed, and never tested, given the lack of an analytical method. Without confirmation of natural areas, much biogeography was descriptive; that is, limited to describing and naming areas. There was, and still is, a dominant component to biogeography – the narrative. Knowing the origins and distributional history of species and their genera has been a mainstay of biogeographers since Linnaeus. Narratives about taxic distribution over time, such as dispersal routes for migrations and extinctions, provide a natural history of the organisms in question. Narration is not descriptive or analytical, nor does it necessarily require a method. Over time, our narratives were synthesised in the conclusions to many taxonomic monographs and phylogenetic studies. Biogeography was nothing more than assuming natural biotic areas and telling stories about the distributional histories of its organisms. That is until 1978, when Donn Eric Rosen, an American ichthyologist at the American Museum of Natural History, made a significant breakthrough in how we find the relationships between biotic areas (Rosen 1978). That breakthrough was a result of a new way of doing biological classification – cladistics – and it completely reformed traditional Linnaean taxonomy.

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