Biodiversity (Encyclopedia of Environmental Issues, Revised Edition)
In 1993 the Wildlife Society defined biodiversity as “the richness, abundance, and variability of plant and animal species and communities and the ecological processes that link them with one another and with soil, air, and water.” Included in this concept is the recognition that life on earth exists in great variety and at various levels of organization. Many kinds of specialists—including organismic biologists, population and evolutionary biologists, geneticists, and ecologists—investigate biological processes that are encompassed by the concept of biodiversity. Conservation biologists are concerned with the totality of biodiversity, including the process of speciation that forms new species, the measurement of biodiversity, and factors involved in the extinction process. The primary thrust of their efforts, however, is the development of strategies to preserve biodiversity.
The biodiversity paradigm connects classical taxonomic and morphological studies of organisms with modern techniques employed by those working at the molecular level. It is generally accepted that biodiversity can be approached at three levels of organization, commonly identified as species diversity, ecosystem diversity, and genetic diversity. Some also recognize biological phenomena diversity.
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Species Diversity (Encyclopedia of Environmental Issues, Revised Edition)
No one knows how many species inhabit the earth. Estimates range from five million to several times that number. Each species consists of individuals that are somewhat similar and capable of interbreeding with other members of their species but are not usually able to interbreed with individuals of other species. The species that occupy a particular ecosystem are a subset of the species as a whole. Ecosystems are generally considered to be local units of nature; ponds, forests, and prairies are common examples.
Conservation biologists measure the species diversity of a given ecosystem by first conducting a careful, quantitative inventory. From such data, scientists may determine the “richness” of the ecosystem, which is simply a reflection of the number of species present. An island with three hundred species would thus be considered to be 50 percent richer than another with only two hundred species. Some ecosystems, especially tropical rain forests and coral reefs, are much richer than others. Among the least rich are tundra regions and deserts.
A second aspect of species diversity is “evenness,” defined as the degree to which all of the various elements are present in similar percentages of the total species. As an example, consider two forests, each of which has a total of twenty species of trees. Suppose that the first forest has a few tree species represented by rather high percentages and the remainder...
(The entire section is 568 words.)
Ecosystem Diversity (Encyclopedia of Environmental Issues, Revised Edition)
Ecology can be defined as the study of ecosystems. From a conservation standpoint, ecosystems are important because they sustain their particular assemblages of living species. Conservation biologists also consider ecosystems to have intrinsic value beyond the species they harbor; therefore, it would be ideal if representative global ecosystems could be preserved. This is far from realization, however. Just deciding where to draw the line between interfacing ecosystems can be a problem. For example, the water level of a stream running through a forest is subject to seasonal fluctuation, causing a transitional zone characterized by the biota (that is, the flora and fauna) from both adjoining ecosystems. Such ubiquitous zones negate the view that ecosystems are discrete units with easily recognized boundaries.
The protection of diverse ecosystems is of utmost importance to the maintenance of biodiversity, but ecosystems throughout the world are threatened by global warming, air and water pollution, acid deposition, ozone depletion, and other destructive forces. At the local level, deforestation, thermal pollution, urbanization, and poor agricultural practices are among the problems affecting ecosystems and therefore reducing biodiversity. Both global and local environmental problems are amplified by rapidly increasing world population pressures.
In the process of determining which ecosystems are most in need of...
(The entire section is 418 words.)
Genetic and Biological Phenomena Diversity (Encyclopedia of Environmental Issues, Revised Edition)
Most of the variations among individuals of the same species are caused by the different genotypes (combinations of genes) the individuals possess. Such genetic diversity is readily apparent in cultivated or domesticated species such as cats, dogs, and corn, but it also exists, though usually to a lesser degree, in wild species. Genetic diversity can be measured only through the use of exacting molecular laboratory procedures. Such tests detect the amount of variation in the deoxyribonucleic acid (DNA) or isoenzymes (chemically distinct enzymes) possessed by various individuals of the species in question.
A significant degree of genetic diversity within a population or species confers a great advantage. This diversity is the raw material that allows evolutionary processes to occur. When a local population becomes too small, it is subject to a serious decline in vigor from increased inbreeding. This leads, in turn, to a downward, self-perpetuating spiral in genetic diversity and further reduction in population size. Extinction may be imminent. In the grand scheme of nature, this is a catastrophic event; never again will that particular genome (set of genes) exist anywhere on the earth. Extinction is the process by which global biodiversity is reduced.
The term “biological phenomena diversity” refers to the numerous unique biological events that occur in natural areas throughout the world....
(The entire section is 433 words.)
Further Reading (Encyclopedia of Environmental Issues, Revised Edition)
Chivian, Eric, and Aaron Bernstein, eds. Sustaining Life: How Human Health Depends on Biodiversity. New York: Oxford University Press, 2008.
Ehrlich, Paul R., and Anne H. Ehrlich. Extinction: The Causes and Consequences of the Disappearance of Species. New York: Ballantine Books, 1981.
Hunter, Malcolm L., Jr. Fundamentals of Conservation Biology. 3d ed. Hoboken, N.J.: Wiley-Blackwell, 2006.
Novacek, Michael J., ed. The Biodiversity Crisis: Losing What Counts. New York: New Press, 2001.
Primack, Richard B. Essentials of Conservation Biology. 5th ed. Sunderland, Mass.: Sinauer Associates, 2010.
Ray, Justina C., et al., eds. Large Carnivores and the Conservation of Biodiversity. Washington, D.C.: Island Press, 2005.
Wilson, Edward O. Biophilia. 1984. Reprint. Cambridge, Mass.: Harvard University Press, 2003.
_______. The Diversity of Life. New ed. New York: W. W. Norton, 1999.
Zeigler, David. Understanding Biodiversity. Westport, Conn.: Praeger, 2007.
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Background (Encyclopedia of Global Resources)
Conservation was a priority in the United States in the late 1800’s and early 1900’s, but efforts were driven by the mistaken beliefs that there were regions untouched by humanity and that humans were not part of nature. Intensified use of lands leading up to and during World War II hastened the loss of species and wilderness areas. The science of ecology was emerging but “natural” ecosystems were hard to identify. Thus, conservation efforts in the 1960’s and 1970’s focused on the preservation of particular species in order to preserve biodiversity and led to passage of the Endangered Species Preservation Act in 1966. Political support for protecting the environment and biodiversity spread globally, leading to the 1992 Earth Summit, in which representatives of 175 nations met in Rio de Janeiro, Brazil. As of 2009, all countries present at the summit, except the United States, had ratified the agreements. All participating countries were expected to identify, monitor, and report on various aspects of biodiversity within their borders; help deteriorating regions recover; include indigenous peoples in discussions of biodiversity; and educate citizens about the importance of biodiversity. Preservation of original habitats was preferred over off-site recovery efforts.
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Recognizing and Measuring Biodiversity (Encyclopedia of Global Resources)
Biodiversity can be subdivided for analysis into a nested hierarchy of four levels (genetic, population or species, community or ecosystem, and landscape or region) or it can be studied in terms of composition (genetic constituency, species and relative proportions in a community, and kinds and distribution of habitats and communities), structure (patterns, sequence, and organization of constituents), and function (evolutionary, ecological, hydrological, geological, and climatic processes responsible for the patterns of biodiversity). Diversity likely enhances stability of the ecosystem, defined as the physiochemical setting associated with a community of living organisms in complex, multifaceted interactions. Biodiversity is one characteristic of an ecosystem, and the simplest measure of diversity is the number of types of organisms (usually species or another group of organisms in the Linnaean classification system). Alpha diversity is the number of types of organisms relative to abundance, and beta diversity is a relative measure of how much an ecosystem adds to a region.
Species richness measures are typically favored in conservation planning as a proxy for overall level of biodiversity. However, there are many definitions of species, and species can be hard to identify no matter what one’s theoretical biases (whether one prefers to explain species change by differing contributions of the...
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Valuing Biodiversity (Encyclopedia of Global Resources)
In the 1950’s, biologists assumed that increasing biological diversity stabilized ecosystems because any single aspect of an ecosystem, if changed, should be less disruptive the greater the level of complexity. In the 1970’s, mathematical modeling of complex systems confirmed that instability increased with biological complexity, a view that was favored until the models proved inadequate to describe all the varying aspects of living ecosystems. Nonequilibrium (unpredictable) processes also affected species diversity. Thus, interest continued in the relationship between measures of biodiversity and productivity, which was the focus of much experimental research in artificial and natural settings in the 1990’s. However, few simple associations were found, making the outcome of a disruption to a particular ecosystem difficult to predict.
Some diversity is not evident. For example, biodiversity is partly determined by genes that may be somewhat or fully expressed, depending on the selective demands of local conditions. Gene expression is also sensitive to developmental context as well as selection pressures as the organism survives to reproduce. The prior history of a lineage (phylogeny) is also relevant. Precipitous population declines can reduce genetic variability in a lineage, likely lowering its flexibility in surviving environmental disturbances. Larger populations are more likely to inhabit more diverse settings...
(The entire section is 480 words.)
Managing Biodiversity (Encyclopedia of Global Resources)
Humans are part of an evolving lineage and are also part of global biodiversity. Human population growth and the integration of rural, formerly isolated peoples into the global economic system have led to extensive losses of human languages, worldviews, and knowledge about local ecologies and biodiversity. No human group should be forced to live on the brink of starvation with high rates of mortality and be excluded from discussions about their region’s biodiversity. In addition, humans scrambling to survive also have suppressed immune systems and are vulnerable to epidemic disease.
Protection and adequate management of biodiversity require that humanity give up the typical short-term, immediate-needs perspective dominated by the most wealthy and politically influential interests and move in the direction of collaboration among diverse interests, including all levels of government, nongovernmental organizations, the public, industry, property owners, developers, and scientists representing academia, government, and industry. The planning and associated decision making must include focus on both public and private lands.
Contemporary agricultural systems influence and are influenced by surrounding ecologies less affected by human activities. Genetically modified plants may introduce traits that can alter their “wilder” cousins. Agricultural biodiversity has also been declining at precipitous rates because of...
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Conservation (Encyclopedia of Global Resources)
Preservation of species in their natural (in situ) settings involves legislation to protect species, setting aside protected areas, and devising effective management plans, all of which are expectations of the agreement made at the Earth Summit. A reserve may include a less disturbed core surrounded by buffer zones that differ in the intensity of human use. The designs of reserves are influenced by the research and theory of the discipline of ecology. Larger protected regions are better than smaller; closely placed blocks of habitats are better than widely spaced blocks; and interconnected zones are better than isolated ones. All planning must involve the local peoples living in or adjacent to the protected regions.
Many situations exist in which there is too much disturbance by humans or the remnant population is too small to survive under current conditions. Thus, the maintenance of these species in artificial ex situ (off-site) conditions—such as zoos, aquariums, botanical gardens, and arboretums—under human supervision becomes necessary. Sometimes captive colonies can be used to introduce species into the wild. Seed banks and sperm preservation are other ways to conserve genetic diversity, an idea initially pushed by Nikolai Ivanovich Vavilov in the early twentieth century. Gary P. Nabhan advocates a means of increasing the biodiversity of local plants and the resulting foods in a sustainable manner by creating markets...
(The entire section is 266 words.)
Further Reading (Encyclopedia of Global Resources)
Chivian, Eric, and Andrew Bernstein. Sustaining Life: How Human Health Depends on Biodiversity. New York: Oxford University Press, 2008.
Cockburn, Andrew. An Introduction to Evolutionary Ecology. Illustrated by Karina Hansen. Boston: Blackwell Scientific, 1991.
Farnham, Timothy J. Saving Nature’s Legacy: Origins of the Idea of Biological Diversity. New Haven, Conn.: Yale University Press, 2007.
Groves, Craig R. Drafting a Conservation Blueprint: A Practitioner’s Guide to Planning for Biodiversity. Washington, D.C.: Island Press, 2003.
Jarvis, Devra I., Christine Padoch, and H. David Cooper, eds. Managing Biodiversity in Agricultural Ecosystems. New York: Columbia University Press, 2007.
Jeffries, Michael J. Biodiversity and Conservation. 2d ed. New York: Routledge, 2006.
Ladle, Richard J., ed. Biodiversity and Conservation: Critical Concepts in the Environment. 5 vols. New York: Routledge, 2009.
Lévêque, Christian, and Jean-Claude Mounolou. Biodiversity. New York: John Wiley and Sons, 2003.
Louka, Elli. Biodiversity and Human Rights: The International Rules for the Protection of Biodiversity. Ardsley, N.Y.: Transnational, 2002.
Lovejoy, Thomas E., and Lee Jay Hannah, eds. Climate Change and Biodiversity. New Haven, Conn.: Yale University Press, 2005.
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Background (Encyclopedia of Global Warming)
Biological diversity allows myriad species to work together to maintain the environment without costly human intervention. Thus, biodiversity is an irreplaceable natural resource crucial to human well-being. Habitat destruction, pollution, invasive species, overexploitation, and global climate change have led to an accelerated decline in biodiversity in recent decades. As a result, the current rate of species extinctions is estimated at one hundred to one thousand times greater than the natural rate. If the biodiversity decline is not slowed, Earth will be much less inhabitable for future generations.
(The entire section is 87 words.)
Past and Current Extinctions (Encyclopedia of Global Warming)
There is no doubt that climate plays a central role in fluctuations of biodiversity. At least four out of five recognized mass extinction events on Earth are attributable to climate changes. The Triassic event (around 200 million years ago) was triggered by atmospheric carbon dioxide (CO2) levels increasing to one hundred times the current level. The Permian-Triassic extinction (about 251 million years ago), the greatest mass extinction on record, resulted from global temperature rises to between 10° and 30° Celsius higher than today’s average temperature. That single event is believed to have wiped out 95 percent of the life in Earth’s oceans and nearly 75 percent of terrestrial species.
Climate change has also led to the emergence of new species. In fact, some experts believe that rapid climate changes in Africa might have created suitable conditions for the emergence of modern humans. In particular, rapid changes in water sources are believed to have forced primitive hominids rapidly to change and adapt. Under this theory, Homo sapiensevolved from its progenitor species as a result of these changes. In general, however, the birth of new species following a mass extinction usually takes millions of years. Recovery from severe losses of biodiversity does not occur on a human timescale.
Many experts believe that Earth is currently in the midst of a sixth mass extinction event. Although there...
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Impact of Climate Change on Biodiversity (Encyclopedia of Global Warming)
Climate changes can affect species in a number of ways. These include the expansion, contraction, and shift of habitats; changes in temperature, precipitation, and other environmental conditions; increased frequency of diseases; emergence of invasive species; and disrupted ecological relationships. With a rising temperature, extreme and severe weather events will become more frequent, including extreme high temperatures, extreme severe storms, large floods, a decrease in snow cover and ice caps, rising sea levels, and alteration to the distribution of infectious diseases and invasive species.
As temperatures rise, habitats for many plants and animals will be altered, eliminating the homes and niches to which they have adapted. It is estimated that up to 60 percent of northern latitude habitats could be affected by global warming. In response to global warming, plants and animals will migrate to more suitable climes. Specific effects have already been observed. The tree line near Olympic National Park has moved up in altitude by more than 30 meters since the 1980’s. The red fox is spreading northward in Australia in response to the warming climate. Many fish species along the Pacific coast are shifting their habitats northward in search of cooler waters.
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Biodiversity Loss Due to Human Activities (Encyclopedia of Global Warming)
Before the rapid explosion of human populations, many species may have responded to climate change by migrating northward or southward to the cooler regions. Contemporary human activities such as urbanization, road construction, agriculture, and tourism have fragmented, converted, and destroyed many habitats and potential migration routes and thus make it much more difficult for species to migrate. As a result, many species struggle to cope with climate change as they decline in population, often facing outright extinction.
The replacement of low-intensity farming systems with industrial agro-ecosystems has led to a significant decline in biodiversity. For example, the deforestation of tropical rain forests represents an alarming threat to biodiversity. In some regions, forest cover remains high, but intensive management has turned natural forests into stands of very few or single tree species, leading to the loss of many animal species as well. The disappearance of wetlands worldwide has been dramatic over the last century, ranging from 60 percent in China to 90 percent in Bulgaria. The living planet index declined by 37 percent between 1970 and 2000.
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Context (Encyclopedia of Global Warming)
The loss of biodiversity is both real and accelerating, as Earth continues to warm. Approximately 25 percent of conifers, 52 percent of cycads, 12 percent of bird species, 23 percent of mammals, and 32 percent of amphibians are threatened with extinction. The irreversible loss of biodiversity poses serious threats to the well-being of present and future generations. The societal response to this threat has been slow, stemming from a lack of awareness of the vital role biodiversity plays. The key to the solution is education.
There is often a perception of conflict between the need to preserve biodiversity and the goal of economic development. Policy makers and businesses will need to work together to encourage and reward economic development that is friendly to biodiversity. Biodiversity is more complex than many other environmental concerns because it involves several levels of biological organization, including genes, individuals, species, populations, and ecosystems. It cannot easily be measured by a single indicator such as temperature or rainfall. Nevertheless, countries can work together to build consensus and achievable goals aiming at slowing down the biodiversity decline or even restoring habitats for the recovery of threatened species.
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Further Reading (Encyclopedia of Global Warming)
Braasch, Gary. Earth Under Fire: How Global Warming Is Changing the World. Afterword by Bill McKibben. Berkeley: University of California Press, 2007. Very important topic clearly presented and supported by photographs and firsthand data the author collected during his travels around the world. The author’s research is meticulous, his reasoning is sound, and his conclusion is clear.
Emanuel, Kerry. What We Know About Climate Change. Cambridge, Mass.: MIT Press, 2007. Useful reference summarizing what is and is not known about global warming. Arguments are well substantiated.
Fotherqill, Alastair, et al. Planet Earth: As You’ve Never Seen It Before. Berkeley: University of California Press, 2006. As a companion to a television series on Discovery Channel and the British Broadcasting Corporation, this remarkable book depicts natural wonders and represents an eloquent rallying call to significantly strengthen efforts to preserve these wonders. Illustrated with spectacular color photographs.
Lovejoy, Thomas E., and Hannah Lee, eds. Climate Change and Biodiversity. New Haven, Conn.: Yale University Press, 2005. Series of essays, well edited and presented in a cohesive flow. A must read for all who love nature and wildlife and want to know the impacts of climate change upon them.
(The entire section is 192 words.)
Biodiversity (Encyclopedia of Public Health)
The continued health of human societies depends upon a natural environment that is productive and contains a wide diversity of plant, animal, and microbe species. Life on the earth comprises at least 10 million species of plants, animals, and microbes, while in the United States there are an estimated 750,000 species, of which small organisms such as anthropods and microbes comprise 95 percent.
The sustainability of the forest ecosystems and other natural ecosystems are in danger from the expanding world population, which now totals more than 6 billion. With an estimated growth rate of 1.4 percent per year, it is projected to reach 12 billion by the year 2050. Further, due in large part to the growing human population and diverse human activities (supported in large part by fossil fuels), the current extinction rate of species ranges from approximately 1,000 to 10,000 times higher than natural extinction rates. This is alarming for several reasons. Foremost, biodiversity is essential for the sustainable functioning of agricultural, forest, and natural ecosystems upon which human survival and health depends. The loss of a key species (e.g., loss of a predator) creates an imbalance among the remaining species, and can sometimes result in the collapse of the entire ecosystem. Altering a habitat may also improve the environment for an infectious disease, like dengue.
Species diversity affects the quantity and quality of human food supply. For example, conserving pollinators and natural enemies of pests is essential for successful grain, fruit, and vegetable production. Improving food production decreases malnutrition. Yet, at present, the rapidly expanding human population is intensifying the need for increased food supplies. In the year 2000, more than 3 billion people were suffering from malnutritionhe largest number and proportion of people to date. Each year, between 6 million and 14 million people die from the effects of malnutrition.
In many parts of the world, especially in developing countries (e.g., in the Sahelian region of Africa), severe shortages of vitamin A are causing blindness and even death. Worldwide, approximately 250 million children are vitamin A deficient, and each year vitamin A deficiency causes approximately 2 million deaths and 3 million serious eye problems, including blindness.
Similarly, iron intake per person has been declining, especially in sub-Saharan Africa, South Asia, the People's Republic of China, and South America, because overall shortages of food result in inadequate nutrition. In 1998 more that 2 billion persons were sufficiently iron deficient to cause anemia in 1.2 billion people. An estimated 20 percent of the malnutrition deaths are attributed to severe anemia.
Malnutrition is also associated with parasitic infections that are found in areas were conditions of poverty and inadequate sanitation also exist. The health of malnourished individuals, especially children, is seriously affected by parasitic infections, because their presence reduces the availability of nutrients. Parasitic infections diminish appetites while increasing the loss of nutrients by causing diarrhea and dysentery. Hookworms, for instance, can suck as much as 30 milliliters of blood from an infected individual each day, lowering his or her resistance to other diseases. Because an estimated 5 to 20 percent of an individual's daily food intake is used by the body to offset the effects of parasitic illnesses, the overall nutritional status of a parasite-infected person is greatly diminished over time.
As a human population continues to expand and biodiversity declines, waste grows and its disposal becomes a major environmental problem. Each year the total quantity of waste produced by humans, livestock, and crops weighs about 38 billion tons worldwide. Numerous invertebrate animals and microbes function to degrade and recycle wastes. Their preservation in ecosystems is essential to maintain a healthy and productive environment.
Worldwide chemical waste and pollution are also major environmental problems. In the twenty-first century in the United States, 80,000 different chemicals are used and released into the soil, water, and air; worldwide, an estimated 100,000 chemicals are used. In the United States, more than 1,100 kilograms of chemicals per person are used each year; nearly 10 percent of these are known carcinogens. Each year nearly 3 billion kilograms of pesticides are applied worldwide. These toxic chemicals cause 26 million human poisonings annually, with about 220,000 deaths, and affect approximately 750,000 people with chronic diseases like cancer.
Approximately 75 percent by weight of the chemicals released into the environment can be degraded by biological organisms. Thus, species biodiversity helps provide continuous cleanup of contaminated sites (such as residue of pesticides in agriculture), and has a significant advantage over other techniques. Conserving beneficial natural enemies not only controls crop pests but also helps reduce the amount of pesticides applied.
In addition to degrading chemicals, some invertebrate and microbe species also degrade and recycle biological pollutants in water resources. Again, the biological pollution problem is particularly serious in developing nations. About 1.2 billion people in the world lack clean, safe water because most household and industrial wastes are dumped directly into rivers and lakes without treatment. This pollution contributes to the rapidly increasing incidence of diseases in humans. Waterborne infections account for 80 percent of all infectious diseases worldwide and 90 percent of all infectious diseases found in developing countries. A lack of sanitary conditions contributes to about 2 billion human infections of diarrhea, resulting in about 4 million deaths, per year, mostly among infants and young children.
Sometimes altering a natural habitat inadvertently leads to the spread of an infectious disease. Diseases like schistosomiasis that are associated with contaminated fresh water are expanding worldwide. In 1999 it was estimated that schistosomiasis caused 1 million deaths per year. The escalation of the incidence of this disease followed an increase in suitable habitats for the snail that serves as the intermediate host of the causative agent, Schistosoma mansoni. Thus, construction in 1968 of the Aswan High Dam in Egypt and its related irrigation systems was followed by an explosion in the prevalence of Schistosoma mansoni, which increased in the human population from 5 percent in 1968 to 77 percent in 1993.
Considered together, the natural biodiversity of plants, animals, and microbes functions in many ways to enhance the health and quality of life enjoyed by human society. In view of the likely continued growth in human population, and the resultant alteration of the earth's fragile natural ecosystem, greater efforts must be made to conserve biodiversity as a natural and essential treasure.
(SEE ALSO: Climate Change and Human Health; Demographic Trap, Drinking Water; Ecosystems; Endangered Species Act; Environmental Determinants of Health; Famine; Groundwater Contamination; Land Use; Municipal Solid Waste; Nutrition; Ocean Dumping; Pesticides; Pollution; Population Density; Population Growth; Sanitation; Species Extinction; Sustainable Development; Wastewater Treatment; Water Quality)
Heywood, V. H. (1995). Global Biodiversity Assessment. Cambridge, UK: Cambridge University Press.
Myers, N. (1994). "Global Biodiversity II: Losses." In Principles of Conservation Biology, eds. G. K. Meffe and C. R. Carroll. Sutherland, MA: Sinauer Associates.
Pimental, D. (1997). Techniques for Reducing Pesticides: Environmental and Economic Benefits. New York: John Wiley.
Pimental, D., and Pimentel, M. (1996). Food, Energy, and Society, revised edition. Niwot, CO: University Press of Colorado.
Pimental, D.; Tort, M.; D'Anna, L.; Krawic, A.; Berger, J.; Rossman, J.; Mugo, F.; Doon, N.; Shriberg, M.; Howard, E. S.; Lee, S.; and Talbot, J. (1998). "Ecology of Increasing Disease: Population Growth and Environmental Degradation." BioScience 48:81726.
Pimemtal, D.; Wilson, C.; McCullum, C.; Huang, R.; Dwen, P.; Flack, J.; Tran, Q.; Saltman, T.; and Cliff, B.(1997). "Economic and Environmental Benefits of Biodiversity." BioScience 47(11):74758.
Pimm, S. L.; Russell, G. J.; Gittleman, J. L; and Brooks, T. M. (1995). "The Future of Biodiversity." Science 269:34750.
Population Reference Bureau (1999). World Population Data Sheet. Washington, DC: Author.
World Health Organization (1992). Our Planet, Our Health: Report of the WHO Commission on Health and Environment. Geneva: Author.
Biological Diversity (Encyclopedia of Science and Religion)
Biological diversity, or biodiversity, is a generic term for the variety of life on Earth. Such variety is described in Genesis as the "swarms" of creatures Earth brings forth (Gen. 1:20-25). One basic measure of biodiversity is species, though other indicators run a spectrum from genetic alleles (variants) through ecosystems and landscapes. Estimates of the total number of existing species vary from three to ten million (and as much as thirty million), with about 1.5 million described. The unknowns are mostly small invertebrates and microorganisms. Contemporary species inherit their diversity from forms that have gone extinct; diversity overall has increased over evolutionary history. Estimates of the number of species that humans place in jeopardy run from fifteen percent to twenty-five percent of the total. Scientists and religious persons may differ about evolutionary origins but seldom differ about the urgency of conserving biodiversity.
See also ECOLOGY; EVOLUTION
Levin, Simon Asher, ed. Encyclopedia of Biodiversity. San Diego, Calif.: Academic Press, 2001.
Rolston, Holmes, III. "Creation: God and Endangered Species." In Biodiversity and Landscapes, eds. Ke Chung Kim and Robert D. Weaver. New York: Cambridge University Press, 1994.
HOLMES ROLSTON, III