Before reading the text, answer the following questions.

1. Which term characterizes the human impact on the environment?

2. What is an ecosystem?

3. What does an ecologist do?

4. What is recycling?

5. What is pollution?

6. How does pollution affect rivers, oceans, and our ecosystem?

7. What are people doing to stop or control pollution?

Reading A

WHAT IS ECOLOGY?

The scientific discipline of ecology is dynamic, steeped in historical tradition but adapting to its changing environment and building its own ecological network of interactions with other disciplines. Society has become increasingly aware that we are losing crucial parts of our ecosystem, and that the activities of human beings are threatening the sustainability of the biosphere as a life-support system for humanity.

The word "ecology" did not exist when Charles Darwin published his journal, The Voyage of the Beagle, but one can argue that Darwin's account launched ecology as a discipline. Darwin began by reminding his readers that he had previously published volumes on coral reefs, volcanic islands, and the geology of South America. His integration of the physical and biological dimensions of the places where the Beagle stopped, complemented by influential contemporary work by the English naturalist Alfred Russel Wallace, defined a new and synthetic way of looking at nature—in which the patterns characteristic of particular regions found explanation in a unifying, dynamic framework. The term "oekologie" came later, the inspiration of the German scientist and physician Ernst Haeckel, but it was the theories of Darwin and Wallace that created the rich understanding of this science.

Ecology sprang from a marriage between geology and natural history, rooted in observation, but answering a need for a conceptual framework. From its early roots, it became increasingly rigorous and quantitative, and a century later provided the natural discipline for responding to the environmental challenges highlighted by Rachel Carson, Paul Ehrlich, and others.

Fields like ecotoxicology, which studies the fate, transport, and effects of chemicals in the environment, and conservation biology, which seeks to preserve biodiversity, were spawned, closely linked to ecology, but much more applied in focus. The synergy among the disciplines was constructive, but it also tended to blur the distinctions in the public eye between the science of ecology and the application of ecological principles to the management of natural resources. Ecology is a scientific discipline, like physics or molecular biology, whose practitioners are driven by the search for patterns and process in nature. Their findings can inform political decisions about resource use, pollution, climate change, and other environmental issues; but advocacy regarding decisions about our environmental priorities is outside the discipline of ecology. Still, for many people, "ecologist" became a term applied to anyone who wanted to save the planet, or selected parts of it, which made no more sense than calling someone who marvels at the night sky an astronomer.

The application of ecological principles to environmental problems did not suddenly occur with the publication of Silent Spring in 1962; that, like ecology as a whole, had much older roots. The fishing industry provided an early case study nearly a century ago, when the distinguished Italian biologist Umberto D'Anconapuzzled over the causes of fluctuations in the fisheries of the Adriatic. Fortunately, D'Ancona was to marry the daughter of the great Italian mathematician, Vito Volterra, who had become interested in applying his skills in formal mathematics to the study of biological and social systems. Volterra is famous among mathematicians for his contributions to the theory of functionals and integral equations, but is even better and more widely known for the equations he and Alfred Lotka derived independently to describe the dynamics of interacting species. Nevertheless, the greatest contribution Volterra made was not in his specific equations, but rather in the heterodox idea that sophisticated mathematical methods could be used to understand the dynamics of natural systems. The equations of Volterra and Lotkaare taught today in virtually every first course in ecology, and the application of mathematical and computational methods has expanded into every branch of ecology, giving us, for example, integrated models that deal with the interaction between a changing climate and the growth of forests and other vegetation. The influence of mathematics and computation in biology as a whole has also expanded in the last decade, and fields like systems biology (the study of the interplay among the parts of biological systems, like molecular or metabolic systems) and computational biology (with its use of mathematics and computation) have become essential parts of any modern biology department. It should not be lost, however, that through the contributions of Volterra and those who followed his example, ecology was the first sub discipline of biology to become quantitative.

The writings of Darwin and Wallace clearly influenced the development of ecology; but perhaps even more fundamentally, they also launched the field of evolution. The scientific discipline of ecology has thus been, in some sense, a key node in an ecology of scientific disciplines. From its roots in natural history, it has built partnerships with botany and zoology; with geology and paleontology; with mathematics; and with evolutionary studies, from molecular biology to population genetics and development. It has not ignored physics and engineering along the way, in its need to understand the mechanics of how animals and plants grow and move, or how they capture energy and resist stress—why, for example, trees are shaped the way they are. Ecologists make their living by recognizing the interconnectedness of different parts, and different disciplines.

What we must do now, however, is to unify science and the social sciences and humanities further in the service of preserving the earth. That challenge is stretching ecology in new directions. To sustain the planet, we must be able to protect the goods and services ecosystems provide, and that requires knowing what they mean to us. In large part, that is the domain of economics. Bringing ecology and economics together is not new, and most land-grant universities have strong departments of agricultural and resource economics that deal with the economics of agriculture, fisheries, and forests. However, new dimensions in environmental and ecological economics have been developing rapidly, focusing on questions about the value of whole ecosystems, about the optimal design of nature reserves, and about how to manage public goods. Broadly understood, environmental public goods include the air we breathe and the water we drink, the fish we catch and the lakes and oceans that sustain them, as well as the antibiotics that have contributed so much to the advancement of medical care.

Ecology views biological systems as wholes, not as independent parts, while seeking to elucidate how the wholes emerge from and affect the parts. Increasingly, such a holistic perspective, rechristened at places like the Santa Fe Institute as "the theory of complex adaptive systems," has informed understanding and improved management of economic and financial systems, social systems, complex materials, and even physiology and medicine. Essentially, that means little more than taking an ecological approach to such systems.

Task 5