We are currently living in the second most severe extinction epoch in the history of the earth. Species are becoming extinct at an alarming rate, perhaps as many as 100 per day. Who cares? Do you really care about the extinction of a Malaysian bird or a Brazilian beetle or a freshwater clam living in your area? Only you can answer the question as to whether you care or not. For those who do care, the reasons that species should be saved can be divided into conservationist and preservationist reasons.

a)  Conservationist reasoning:

Conservationist reasons argue that species should be saved because they actually are useful to humans.

1) Although seemingly insignificant, many small species are at the bottom of food chains and their loss impacts larger species. For example, although aquatic invertebrates often attract little attention...


humans are interested in the aquatic food chains they support. These aquatic food chains support the fish which are an important source of protein and recreation in addition to a diversity of amphibians, reptiles, birds, and mammals.


3) The food supply: Most of the earth's crops come from 130 different plants; most of these originated from 12 regions of the world where the wild ancestors are still found.   Geneticists often look to these wild species once new strains of pests blight crops.  When blights hit Columbian or Brazilian coffee strains, new wild strains from the Ethiopian highlands were found.  In the late 1970s, grassy stunt virus hit the rice crop of southern and eastern Asia.  After searching 47,000 varieties for a resistant strain, a wild plant was found in an Indian valley that has since been flooded by a hydroelectric dam.

    After searching all 6,500 varieties of barley, the California Agricultural Lands Project found an Ethiopian strain resistant to the yellow dwarf virus that now protects all of California's $160 million barley crop.  The U.S. saves $50 million annually dus to disease resistant wheat genes which came from a seemingly worthless wheat strain from Turkey.  In 1981, British beer industry gained $15 million after incorporating a wild hop plant.  Our crops are bred to decrease genetic diversity; of the vegetable varieties that existed in 1900, only 3% exist today in the U.S.; this leaves crops in danger from new parasites (Gore, ).

4)  Drugs: About 1/4 all U.S. prescriptions are products extracted from plants, 13% from microorganisms, and 3% from animals.  Chemicals from palnts are the source of 80% of the top 150 prescription drugs.  Aspirin was originally isolated from the flower meadowsweet, armadillos are being used in experiments for cures against leprosy because they are the only other organism that can contract the disease.  More than $180 million/year is gained from 2 drugs produced from the small rosy periwinkle (a flower from Madagascar) that cure Hodgkin's disease (affects 5-6,000 Americans annually) and lymphocytic leukemia.  

     Other examples of drugs from plants include: bromelain (controls inflammation), codeine (analgesic), colchicine (anticancer), digitoxin (cardiac stimulant), diosgenin (source of female contraceptive), L-dopa (suppresses Parkinson's disease), ergonovine (migraines & hemorrhaging), glaziovine (antidepressant), indicine N-oxide (anticancer), menthol, morphine, quinine (antimalarial), reserpine (reduces high blood pressure), and scopolamine (sedative).

What would the following plants be worth if a drug could be developed from them? How much are the earth's rainforests worth which contain countless species which have not even been named yet, let alone examined for potential pharmaceutical value?


5) Defense from pests:

The weed plants and insect pests which threaten food production and the insects which can spread disease have wild predators.  Given that insect born diseases (including malaria and West Nile virus) take millions of human lives per year and that the pests which destroy crops cost millions of dollars in damage, what is the value of the wild species which prey on these insects?



6) Ecotourism: 

The United Nations that about $230 billion/year in ecotourism.  Many wild areas and animal species can generate far more income for a country through tourism than through their destruction (the sign along the following South American railway reads "Ecoturismo").

In this country, it is estimated that bird watchers spend more money (and thus have a greater impact on the economy) than do hunters.


b) preservationist reasoning:

In addition to conservationist reasoning which argues that species should be saved because of their potential economic benefit, there are those who value species because of preservationist reasons. Preservationists argue that every species has a right to exist and the all species contribute to the beauty of the world.  Which of the species depicted in the images below could the world do without?  Probably all of them.  If any one of these species disappeared, life on earth would still exist and your life would probably continue unchanged.  Which of the following species would you like to see lost from the world?  Which of the following species do not add to the richness and wonder of the world?  Which of the following species could be lost without the next generation regretting their loss?












capybarasnake in tree