The Emergence of Biodiversity as an Issue of Importance
The Emergence of Biodiversity as an Issue of Importance
Biodiversity, sometimes measured by the total number of different plant and animal species in a given area, emerged as an issue of great importance in the later part of the twentieth century. As an agenda item in many national and global political arenas, it was pushed by both environmental groups and scientists, capturing the attention of the public and politicians alike. Awareness of the potential problem grew in the 1970s and 1980s, while the 1990s saw the first concrete steps taken to halt the decline. This process tends to pit developed nations against less-developed ones to some extent because the greatest amount of diversity tends to be in poorer tropical nations. With much at stake for all parties, this issue is likely to continue to be hotly debated for years or decades to come.
Until relatively recently, man's relationship with the rest of terrestrial life was best summarized by the biblical dictate: "Be fruitful and multiply, and fill the earth and subdue it; and have dominion over the fish of the sea and over the birds of the air and over every living thing that moves upon the earth." Virtually all cultures, religions, nationalities, and groups exercised this degree of dominion at some time or another during their history through farming, hunting, and other activities. Some North American animals were almost certainly exterminated by early Native American hunters, who likely burned clearings for farming and hunting. European settlers were no better, adding advanced technology to make the clearing, planting, and hunting more efficient. Asians have also hunted and, in some places, the terrain is so heavily terraced for rice production that the original contours of the land are impossible to ascertain. The Aztec, Maya, and Inca nations cleared fields, planted crops, and hunted extensively, as did many African nations and the New Guinea highlanders. In Australia many large native mammals disappeared coincidentally with the first human settlements. In short, it seems to be human nature to exploit our environment for our gain, even when doing so is injurious to the environment. However, it must also be pointed out that this same trait is what propelled humanity forward, for it was not until we mastered some aspects of our environment that we could begin to develop and exploit our natural tools of intelligence, an opposable thumb, upright posture, and adaptability.
In the nineteenth century, scientists become aware that species were not a permanent part of nature, that species could become extinct. With this realization and the growing acceptance of evolutionary theory came the unavoidable corollary that species could also be driven into extinction. This fact was witnessed with the documented extinction of the Carolina parakeet, the passenger pigeon, and, perhaps most famously, the dodo. At the same time, however, colonial powers continued planting colonies for economic gain and newly-independent nations, most of them in tropical regions, began to assert their own economic interests.
By the 1960s most of the former colonies had vanished, leaving many resource-rich and cash-poor young nations. Most of these nations had little to no industry because, as colonies, their mission was to send raw materials to the factories of the imperial country. With a profound lack of skilled workers and manufacturing plants in which to work, these nations either turned to agriculture, continued selling their natural resources, or tried to settle their frontiers. All of these options led to clearing forests to free land for commercial and economic purposes.
With the growing impact of the environmental movement in the 1960s came an increasing awareness of what had been lost in the developed nations and what was potentially at stake in the new tropical states. This was a time, too, when scientists began to discover an increasing number of useful compounds that could be created from plants and animals, including new types of drugs and foods. Other scientific studies, originally begun on islands, showed that patches of rainforest left standing between clear-cut areas came to resemble islands, whose size, determined the species diversity that could be supported. Finally, climatologists pointed out the tremendous impact of rain forests on global climate, particularly their role in the removal of pollutants from the atmosphere, the generation of oxygen, regulation of the global carbon cycle, and the moderation of rainfall patterns. Thus, to some extent, pharmaceutical companies, climate scientists, and island biogeographers came together to point out that the continued exploitation of the rain forests could have long-term effects on the quality of human life, as well as the livability of the Earth as a whole.
There are a great many areas in which biodiversity is threatened or has been severely depleted. Indonesia suffered from extensive forest fires in 1997 and 1998, the nearly universal forest of eastern North America has all but vanished, and coral reefs are under attack in Australia and near Florida. However, it may be instructive to focus attention on the condition of the Amazon rain forest, as it is the largest, possibly the most threatened, and the best known of such examples. It is also safe to say that the example of the Amazon is fairly typical.
The recent appreciation of the importance of biodiversity has led to a number of significant developments in the modern world, particularly in terms of scientific and medical research, ecological effects, and political and economic effects.
There is a long history of using natural compounds for medical care. In fact, until very recently, all medical treatments were found in natural substances because, until the advent of modern chemistry, there was no way to reliably synthesize compounds. Although traditional treatments were often dismissed by scientists, awareness has grown that many natural compounds are far superior to synthetic alternatives for the treatment of disease. This led to a growing appreciation of the role the Amazon rain forest can play in the quest for more effective medicines and other treatments, as the Amazon contains a large fraction of the world's genetic diversity.
At the same time, the global food supply is now being viewed as somewhat tenuous because of the widespread use of just a few genetic varieties of the major crops. This raises the specter of widespread famine should a disease or parasite emerge that attacks one or more major crops. Such a pestilence, if spread worldwide by modern transportation, could eliminate a large part of global grain production in a short period of time. The Irish potato famine of 1845-47 resulted in the deaths of over 1 million people and precipitated the emigration of another 1 or 2 million from a single small nation that, even today, has a population of only about 4 million. If the world's wheat or rice crops were to suffer a similar fate, the effect would be global and catastrophic. For this reason, scientists are turning to the tropics for genetic variability and potential new crops, hoping that new species may be amenable to domestication or that genetic advantages of some species may be transferable to existing crops to help make them more resistant to disease.
The ecological effects of rain forest loss are briefly described in the preceding section. Of these, the effects on terrestrial climate are still poorly understood. However, the aspects of island biogeography that apply to loss of rain forest are fairly well understood and are significant.
Simply put, small areas hold fewer species than do large areas. Furthermore, a number of small areas will, in composite, hold fewer species than a single large area of the same area as the combined smaller areas. In the case of the Amazon, clear-cutting or burning large swathes of rain forest for lumber, agriculture, or population expansion typically leaves stands of trees that act as islands of diversity in a sea of farmland or bare soil. As time passes, the genetic diversity of these stands decreases because species that have large ranges cannot support a stable breeding population and die out. Then, the species that depend on them die out, followed by the species that depend on them, and so forth until the "islands" are left with a greatly simplified ecosystem containing only a fraction of its original diversity. Given that some species have extremely limited ranges (some are limited to individual mountains, hills, or valleys), this "island effect" can rapidly lead to the extinction of a large number of species in a relatively short period of time.
In the recent past, with the growing awareness of the importance and relative fragility of the Amazon and other rain forests, many of the developed nations have been pressuring developing nations to preserve their remaining wilderness regions. In many cases, this pressure is the direct or indirect result of political pressure from ecologically concerned constituents. In most cases, this unwanted outside pressure is not warmly received.
Most developing nations point out that the developed world reached that status by exploiting their own natural resources and, when they were exhausted, by exploiting those of their colonies. They then point out the hypocrisy of such a stance on the part of the developed nations, most of whom continue to use resources at a rate far in excess of the rest of the world. In addition, the developing nations note that they are simply trying to improve their economies and standards of living through the same paradigm used by the developed nations. They argue that refusing to use what raw materials they have places them and their citizens at a significant disadvantage in terms of quality and length of life, national wealth, and other factors. Finally, it is often suggested that the developed nations are simply trying to hold less developed nations in an economically and politically disadvantaged position, the better to continue practicing political and economic domination. The developed nations, on the other hand, contend that they have learned much in the past century and are trying to save new countries from making the same mistakes. This debate is far from being settled and will likely continue for the foreseeable future, with its ultimate resolution difficult to predict.
P. ANDREW KARAM
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