THINK OF THESE: Biodiversity on the brink

Two of the most important anti-cancer drugs in the world come from the rosy periwinkle, found in Asia’s tropical rainforests.  Taxol, the only drug that shows promise against breast cancer and ovarian cancer, was initially found in the western yew.  Asian cattle have been crossed with dairy breed of Europe to boost their milk and meat output.

The rosy periwinkle and Asian cattle are part of the region’s biological diversity (biodiversity).  “If nature and natural resources were measures of economic wealth, the Asia and the Pacific region would be one of the Earth’s richest,” notes Eric Van Zant in an article he wrote for ADB Review, a publication circulated by Asian Development Bank.

“Biodiversity” became an environmental buzzword during the 1980s, when prominent biologists warned that human activities were causing a cascading loss of plant and animal species.  The term denotes the full abundance of plant, animal, and microbial life and the ecosystems of which these species are parts.

“The diversity of plants and animals makes life possible on earth, playing a critical role in food security, poverty alleviation, provision of water, medicine and a healthier environment,” explained Elisea Gozun, former secretary of the Department of Environment and Natural Resources.

So far, less than one percent of tropical plants have been screened for medical uses. Also, only 5,000 species of higher plants have been studied as potential medicinal sources.  In the Philippines, for instance, at least 68 common plants are being used as medicines.

“We are losing biodiversity at an unprecedented rate,” decried the UN Food and Agriculture Organization (FAO) of the United Nations during the World Food Day celebration in 1993.

“The loss of biodiversity is a major barrier to development already and poses increasing risks for future generations,” appraised Dr. Walter Reid, then the director of UN Millennium Ecosystem Assessment.

Unfortunately, the world’s biodiversity is collapsing at nothing less than mind-boggling rates.  “Difficult as it is to accept, mass extinction has already begun,” deplores Pulitzer Prize-winning author and scientist Edward O. Wilson.

No one knows the true scope of biodiversity – how many species of plants and animals share the planet with human beings.  Most estimates put the number at somewhere between 10 million and 30 million, with some consensus around the figure of 14 million.  In any case, only about 1.7 million species – a small share of the total – have been identified and categorized, while even fewer have been studied.  Yet, over a thousand, maybe 10,000 more, are being lost each year, mostly unseen and unrecorded.

“The extinction rate is over 150 species a day,” estimated William Mansfield, former deputy director of the United Nations Environment Program, in 1990.

“Of all the global problems that confront us, species extinction is the one that is moving the most rapidly and the one that will have the most serious consequences,” contends Dr. Peter Raven, another noted American biologist.

Unlike other global ecological problems, he stressed, the crisis is completely irreversible.  “Extinction is forever,” said the Washington-based Worldwatch Institute.

Species become extinct is not a new phenomenon. Evolutionary history has witnessed continuous births and deaths of species – the fossil record reveals that there have been at least five major extinctions in the past 500 million years.

But in recent years, the speed with which organisms are being lost has become a major concern.  “Modern agricultural and industrial practices, combined with large increases in population and changing consumption patterns, have all taken their toll,” reports Dr. Cristián Samper, director of the Smithsonian Museum of Natural History in Washington DC.

British ecologist Norman Myers, who alerted the world to the dangers of deforestation in 1980, was the first to identify a series of “hotspots” in which rainforest biodiversity was especially at risk.  The Philippines has been identified as one of the five “hottest of the hotspots.”  The reason: More than 50 percent of the country’s biodiversity is found nowhere else in the world.

According to the U.S. National Academy of Sciences, a typical patch of rain forest covering 10.4 square kilometers contains 750 species of trees, 750 species of other plants, 125 species of mammals, 400 species of birds, 100 species of reptiles and 60 species of amphibians.

One reason why loss of tropical forests has such a dramatic effect on species is that many organisms living in the forests are endemic to a single area. This rarity makes the species particularly vulnerable to extinction.

As they are fast disappearing, biodiversity must be conserved now.  “Unless biodiversity loss can be slowed, species numbers could fall below a critical threshold beyond which they are unlikely to recover,” says Dr. Samper.

“Yet efforts to prevent this scenario must be compatible with promoting the well-being of the human societies that frequently – particularly in the developing world – live in close proximity. This means promoting development policies that simultaneously preserve biodiversity and enrich the livelihoods of those societies in close contact with it.”

Environmentalists are urging everyone to help preserve and protect the remaining biodiversity.  Naturalist William Beebe reminds, “When the last individual of a race of living beings breathes no more, another heaven and another earth must pass before such a one can be again.”