Species Become Extinct. So What?
species never return. A species arises only under a unique situation in
which there is a great deal of genetic diversity in a population that
matches the opportunities provided by a unique and currently unoccupied
of new species depends critically on diversity of genes and diversity of
niches. But human activity is producing the opposite at alarming rates.
We eliminate many niches by creating habitats suitable for our species
(example: we wipe out a forest to build a housing development). We drive into extinction plant and animal species at a rate
of about one species per day. The unique genes of these extinct plants and animals
are lost forever. Our
selective breeding of plants and animals creates uniformity in gene pools. Evolution of new species, which
has usually taken thousands or millions of years, will proceed at even
slower rates. There is no way that the pace of new species can keep up
with the rate of extinction.
Why Humans Are the Ecological Problem
Human population growth increases the demand for food, water, and energy. At some point, the world population must reach the earth's maximum capacity to support the species. At that point, a remedy will be imposed in one or more of the following forms:
All of these possibilities are ugly. Unfortunately, starvation, epidemics, and war have already started in many parts of the world. All three are common in certain parts of Africa. The demand of humans for more food, more water, and more energy not only threatens the human species, but it also devastates ecosystems in which other species lives.
Consider agriculture. Clearing jungles to create pastures changes a rich ecosystem that can support hundreds of species into an impoverished one that supports only a few species. The solution, according to Dr. Norman Borlaug, the "Father of the Green Revolution" and a professor at Texas A&M University, is not to destroy more forests and jungles to create more farm land. The solution is to make the land we currently use for farming even more productive. The "Green Revolution" is well underway in Third World countries where agricultural productivity is being improved by better strains of plants and animals, and more use of fertilizer, herbicides, and pesticides. Modern agricultural practices not only provide more food, but by doing so without using more land, they produce a dramatic conservation effect. Dr. Borlaug says that if the world were still getting the low crop and livestock yields like those in 1950, at least half of today's 16 million square miles of global forest would already have been cut and plowed - and all the rest would be have to be destroyed in the next three decades.
Click here for the United Nations Web site on world-wide agriculture.
Political problems are preventing completion of the Green Revolution.
Some environmentalists say that low-yield farming is more "sustainable." But Borlaug says that Africa proves that low-yield farming is sustainable only in the face of higher death rates. In many parts of Mexico, peasants farm in the same inefficient way that their Mayan ancestors did 2000 years ago. The problem of too many people with too little food is made worse by the lack of birth control. Peasants around the world are caught in a downward spiral of trying to have bigger inefficient farms by destroying the jungle and forests. How sustainable is that?
Are humans smart enough to save themselves and their environment? Maybe human evolution is not yet finished.