There are many direct benefits of preserving species. One of the most obvious is that of medical advancement. Chemicals found in certain plant species have greatly helped to improve medical technology and treatment. The extract of the leaves of a periwinkle plant from Madagascar contains two alkaloids, vincristine and vinblastine, that have been used to treat Hodgkin's disease, leukemia, cancers, and cancerlike diseases (including breast cancer and those that afflict young children). If the periwinkle plant had become extinct before this medicinal discovery was made, all of humanity would have suffered a tremendous loss. And the thousands and thousands of leukemia, Hodgkin's disease, cancer patients, family, and friends would have felt that loss the most.
Plants also help human beings fight heart and circulatory disorders. An alkaloid called reserpine from Rauwolfia, a plant related to the periwinkle, is often used to control high blood pressure. One of the most famous examples of plant medicine concerns the 1928 discovery by Sir Alexander Fleming of the mold Penicillium notatum, which launched the antibiotics industry. Penicillin made the war wounds and surgical operations of World War II much less likely to make permanent damage. Antibiotics also treated such diseases like bubonic plague, tuberculosis, epidemic typhus, typhoid fever, scarlet fever, diphtheria, bacterial pneumonia, syphilis, and gonorrhea much more effectively. Consequently, death rates made dramatic declines, while population growth in poorer countries increased. The irony is that the population explosion triggered by antibiotics has caused the habitat loss of many organisms. This, in turn, limits access to new antibiotics and other useful plant products.
It is unfortunate that in-depth experiment with plant species has barely begun. According to conservationist Norman Myers, only 2% of flowering plants have even been tested. The difficulty of discovering new medicines very quickly may be caused by the highly differing location of chemicals in every subspecies. If a certain useful alkaloid is present in the seeds of one plant subspecies, it may be located in the leaves in another subspecies. If human beings don't want to lose the potential of the botanical world, variability within each species must also be preserved. In 1980 alone, the value of plant-derived medicines in the USA probably exceeded $6 billion. If a portion of that figure could be made available to further research in potential drug sources, more advancement could be made and more human lives, and plant species, saved.
In addition to plant life, animals also provide numerous medicinal benefits. Certain marine animals produce chemicals that show tremendous promise as anticancer agents. Antibiotics have already been extracted from marine sponges. Sea anemones, segmented worms, clams, sea cucumbers, sea squirts, moss animals, proboscis worms, sharks, and stingrays also show great potential as anticancer drugs. More species have yielded substances that could become antiviral and antibacterial drugs, anticoagulants, contraceptives, and control ulcers and hyptertension. Cytarabine, a chemical derived from a sponge, is used to treat leukemia and herpes infections. The venom from a Malayan pit viper, a chemical called ancrod, is an anticoagulant, which is used to prevent the formation of blood clots (blood clots can cause heart attacks). The venom of bees can relieve arthritis, and blowfly larvae secretions promote healing.
In addition, there are other alternatives to hunting down endangered species that are economically useful. Other, unendangered organisms can be found in place of those that are threatened. For instance, chimpanzees were previously used to test a vaccine against hepatitis B. However, it was found that Beechey's Ground Squirrel, a common animal in the western United States, was susceptible to a very similar virus and proved to be an excellent subject on which to experiment with the vaccine. For other experimental animals, it may be beneficial to breed them in captivity to preserve the wild species.
Endangered animals are also useful to humans in the provision of food. All of the domesticated plants and animals we humans use today for food are descendants of wild species. Only think what would have happened if those wild species had been wiped out!
Today, the number of malnourished children is almost 170 million, and that is only for those under five years of age. Historically, the solution was to expand agriculture and clear more forests to provide fields of staple crops. However, these disappearing natural areas and the species living in them might have great potential for development into crops. Most of the hungry people are in the tropics, and wheat does not grow well in its warm, humid climate. However, one group of tropical plants of the genus Amaranthus holds great promise as a source of staple crops because its seeds have a very high quality protein. Its leaves are protein-rich and resemble spinach.
Another way of providing enough food for the world's hungry is to cultivate and grow eelgrasses, which grow entirely under the sea. It could act as a substitute for traditional grains in certain seacoast regions. Flour can be made from it, and furthermore, it would not need fresh water, pesticides, or fertilizers. Unexploited plants with amazing potential value exist everywhere, but investment and development of these crops has not expanded. If only they could be further nurtured and grown, much of the world's problems of starvation could be greatly lessened. It seems that the human food situation is extremely vulnerable because it is so dependent on a narrow range of crop species. And expansion of that range is limited by extinction of many plants. Not only this, but the common wheat and corn species are themselves endangered by shrinking genetic diversity.
It would also be beneficial to save the populations within species in an effort to preserve genetic variability. Certain crops are susceptible to rusts, or fungi, and are defended by pest control and their own resistance. However, about every five years, the fungi adapt and threaten them again, so new, resistant crops must be developed. This is done by the combination of genetic types that defend against disease. However, this whole process depends on having a good supply of genetic types to use in the combination process. But that supply is rapidly vanishing. Farmers often grow only one subspecies of a crop because of its high yield. However, this is a dangerous practice because it lessens the gene pool. Only with a high genetic variability will farmers be able to tackle the large variety of crop diseases, and develop hardier strains of plants.
Humans take their protein from just nine species of domesticated animals - cattle, pigs, goats, sheep, water buffalo, chickens, ducks, geese, and turkeys. This is just the tip of the iceberg. Aquaculture, the domestication of marine and freshwater animals, has enormous potential which is hardly being realized. In other areas, it has been recognized that domestication of African grazing animals could produce high yields of meat without causing as many environmental problems as the cattle that are currently being raised there.
Other organisms produce valuable products, a fact that we don't often realize. Many tropical trees may have properties not yet discovered. In the future, the kinds of woods that are desirable may also change with changing technology and scientific progression. A major future energy source could also be biomass. Plants may be grown to be burned in power plants or converted to other fuels. Trees and other plants also provide the following:
So when humans consider the problem of extinction, we should closely examine what are known opportunity costs - the difference in the advantages gained in the process of extermination and the benefits gained from preservation. Do the immediate profits outweigh those in the long run? What potential will we destroy if we act without thinking now? Whatever the outcome, it is glaringly evident that humanity has so much to gain from preservation of endangered organisms, and so much to lose if they are wiped out. If it is done, it cannot be undone. Remember, endangered means there is still time, but extinction means FOREVER.