What is Biodiversity?
Its
complexity is measured in terms of variations at
·
genetic,
·
species,
·
population
and
·
ecosystem
levels.
Earth's
biodiversity is in a natural constant change due to the naturally changing
environment.
Biodiversity
plays a critical role in meeting human
needs
directly while maintaining the ecological processes upon which our survival
depends.
Why
Should We Care About Biodiversity?
·
Biodiversity
is a necessity, not a luxury.
In recent years, the loss of entire
species and natural areas, caused almost entirely by human activity, has been
occurring at unprecedented rates.
The extinction of each additional species brings the irreversible loss of unique genetic codes, which are often linked to development of medicines, foods, and jobs.
A
one-acre patch of elm trees produces oxygen, removes carbon from the
atmosphere, and captures at least 16 tons of airborne dirt, which rain then
washes back to the ground as productive soil. 1
Biodiversity not only provides direct
benefits like food, medicine, and energy; it also affords us a "life
support system." Biodiversity is required for the recycling of essential
elements, such as carbon, oxygen, and nitrogen. It is also responsible for
mitigating pollution, protecting watersheds, and combating soil erosion.
Because biodiversity acts as a buffer against excessive variations in weather
and climate, it protects us from catastrophic events beyond human control.2
The importance of biodiversity to a
healthy environment has become increasingly clear. We have
learned that the future well-being of all
humanity depends on our stewardship of the Earth. When we
overexploit living resources, we threaten
our own survival.3
Biodiversity is important to
the global economy.
The economic value of biodiversity is a
well-established fact. Modern agriculture, which depends on new
genetic stock from natural ecological
systems, is now a $3 trillion global business; nature tourism
generates some $12 billion worldwide in
annual revenues.4 In the United States, the economic benefits
from wild plants and animals comprise
approximately 4.5% of the Gross Domestic Product.5
In 1988, worldwide commercial trade in
wild plants (excluding timber) and animals was valued at $5
billion.6 That same year, the 20
best-selling drugs in the U.S., with combined revenues of about $6 billion
worldwide, all relied on plants,
microbes, and animals for their development.7 Each wild plant that provides
the chemical basis for developing new
drugs is projected to generate at least $290 million annually.8
Biodiversity is essential for
ensuring food security.
All of the world's major food crops,
including corn, wheat, and soybeans, depend on new genetic
material from the wild to remain
productive and healthy. Breeders and farmers rely on the genetic
diversity of crops and livestock to
increase yields and to respond to changes in environmental conditions.
Plant breeding, using wild genetic stock
and other sources, was responsible for half the gains in
agricultural yields in the United States
from 1930 to 1980.9
The Earth's oceans, lakes, and rivers
contain an abundance of food resources. At present, food
production from wild stocks of fish is the
single largest source of animal protein for the world's expanding
population. In 1994, more than 10 billion
pounds of fish, valued at about $4 billion, were caught and sold
in the United States alone.10
Teosinte, a wild relative of corn
discovered in Mexico during the 1960s, is resistant to four of the eight
major diseases that kill corn in the
United States.11
Had it been available to U.S. farmers in
the 1970s, losses of $1 billion could have been avoided when
disease wiped out uniformly susceptible
varieties.12 Corn is the essential ingredient in a range of
products-from animal feed to corn syrup.
Thanks to Teosinte, prices for grain-fed meats, soft drinks,
and other corn-related foods have been
kept low. This example shows that genetic biodiversity protects
American farmers and consumers alike.
Biodiversity safeguards human
health.
Of the top-selling 150 prescription drugs
in the United States, 79% have their origins in nature.13 Many
synthetic drugs, including aspirin, were
first discovered in wild plants and animals. Roughly 119 pure
chemical substances extracted from some
90 species of higher plants are used in pharmaceuticals
around the world.14
Traditional medicine, which relies on
species of wild and cultivated plants, forms the basis of primary
health care for about 80% of all people
living in developing countries. In the United States, traditional
medicine and other alternative health
systems are gaining in acceptance. Each year, the U.S. imports
more than $20 million of rain forest
plants valued for their medicinal properties.15
Despite such widespread popularity, only
2% of the 250,000 described species of vascular plants have
been screened for their chemical
compounds.16 Of those that have been screened, some show dramatic
promise. For example, Taxol, a new drug
developed from the Pacific yew tree, is being used to treat
ovarian cancer.17
In 1960, a child with leukemia had a 1 in
5 chance of remission. Now, thanks to anti-cancer drugs
developed from a compound discovered in
wild periwinkle plants, the same child's chance of survival has
increased to 80%.18
Biodiversity provides
recreational opportunities.
In addition to protecting our future food
supply, health, and environment, biodiversity provides an array
of recreational opportunities and
aesthetic value. In 1991, recreation associated with wild birds alone
generated nearly $20 million in economic
activity and 250,000 jobs in the United States, exceeding many Fortune 500
companies.19 Saltwater recreational fishing in the U.S. generates more than $15
billion
annually in economic activity and provides
over 200,000 full-time jobs.20
U.S. parks brought in $3.2 billion from
visitors in 1986.21 That same year, tourism in Kenya amounted to
$400 million. In that country, the
economic value of viewing elephants alone totaled $25 million in 1989.22
These large economic revenues reflect the
high value people place on recreation involving biodiversity.
Biodiversity and the issues
that affect it cross all
national borders.
Air and water pollution do not respect
national borders. Acid rain, which results when air pollutants mix
with falling rain, is a good example. In
North America, industrial emissions from U.S. factories have
caused acid rain to damage sugar maples
in Canada, threatening future maple syrup production.23
Perhaps the most serious threat to life
on Earth is global climate change.24 In December 1995, the
Intergovernmental Panel on Climate
Change, composed of scientists and policymakers from 120 nations,
agreed in writing that human activities
are affecting the global climate.25
Carbon released from such human-induced
activities as the burning of fossil fuels, forests, and other
natural habitats is a major contributor
to climate change.26 Tropical forest burning outside the U.S. has
accounted for about 25% of all carbon
released into the atmosphere over the past decade.27
Rapid build-up of carbon-dioxide and
other greenhouse gases in the Earth's atmosphere, combined
inextricably with ozone depletion, is causing
our climate to change.28 The consequences for many
species of wildlife and ecosystems, as
well as for human populations, may be catastrophic.29 In the
United States, warmer temperatures could
result in the shifting of agricultural lands hundreds of miles
north and cause severe coastal
flooding.30 Species would be forced to migrate to keep up with optimum
conditions, but the rate of change would
be too fast for many to adapt.31, 32
On a global scale, loss of biodiversity
can even threaten national security. There are many national and
international conflicts over water, land,
and other natural resources. Such environmental conflicts often
lead to mass migrations of people that
strain national budgets, public infrastructure, and international
relations.33
Rates of species extinction are
unprecedented.
Not since the disappearance of the
dinosaurs has the rate of species extinction, the most common
measure of biodiversity loss, been higher.
Virtually all of the loss is caused by human activities, mostly
through habitat destruction and
overhunting.34 In the contiguous United States, 98% of virgin forests
have been destroyed, and 54% of wetlands
have been lost.35 Over the past 500 years, 200 species of
plants and 71 species and sub-species of
vertebrates have become extinct in North America alone;
another 750 species are officially listed
as endangered or threatened.36 Unfortunately, only 13% of the
approximately 14 million species that
inhabit the Earth have been described by scientists.37 With
increasing human pressure on biological
resources, rates of extinction can only be expected to
accelerate.
hreats
to Biodiversity
Although it is clear that biodiversity
conservation is vital to human survival, living resources are
increasingly threatened around the world.
Some of the most direct threats and illustrative examples
include:
habitat destruction (burning or
felling of old-growth forests)
overexploitation (overhunting of
elephants and rhinos)
pollution (industrial emissions that
cause acid rain)
global climate change (the greenhouse
effect and destruction of the ozone layer)
invasion by introduced species
(displacement of native songbirds in the U.S. by European
starlings)
These direct threats are often driven by
underlying social conditions, including increased per-capita
consumption, poverty, rapid population
growth, and unsound economic and social policies.
What
is being done to conserve
biodiversity?
Conserving biodiversity is important to Americans.
According to a 1993 public opinion poll, 89% of the
public agrees that human beings have an
ethical responsibility for protecting plant and animal species.38
Seventy-eight percent of Americans
believe that greater protection should be given to fish and wildlife
habitats on federal forest lands, and a
large majority supports the Endangered Species Act.39
Public concern over the protection of
wild plant and animal species often benefits society indirectly. For
example, in 1972, public outcry over the
declining populations of the American bald eagle caused the
U.S. to ban the production and sale of
the pesticide DDT; this chemical was later identified as a serious
cancer-causing agent in humans.
Global concern over the unprecedented
loss of living resources has brought governments together to
draft the International Convention on
Biodiversity. This comprehensive agreement recognizes, for the
first time, that the conservation of
biodiversity is a common concern of all the world's people.40 Already,
more than 100 countries have ratified it.
By adding its signature to the Convention, the United States
would send the global community a strong
message about its commitment to protecting biodiversity.
Public acknowledgement of the importance
of biodiversity has begun to influence U.S. foreign policy.
Increasingly, through the United States
Agency for International Development (USAID) and U.S.-based
nongovernmental organizations, the U.S.
is helping other countries link their economic and social
development with the conservation and
sustainable use of natural resources. Informed leadership,
supported by a growing public awareness,
is critical to meeting the social, economic, and environmental
challenges the world now faces.
What can we do?
As individuals, we can help conserve
biodiversity by:
investing in and supporting
environmentally sound businesses;
supporting local, national, and international conservation
efforts;
minimizing our consumption of
gasoline, electricity, and material goods;
becoming informed about legislation
that affects the world's biodiversity and sharing our concerns
with our elected representatives.
As a society, we can all move to curb our
use of energy, eliminate our consumption and use of
threatened species, and support the
transformation of national and international policies to those that
are more sustainable and less harmful to
biodiversity.
Biodiversity and Conservation:
A Hypertext Book by Peter J. Bryant
Chapter 7: VALUES
OF
BIODIVERSITY
ARGUMENTS FOR CONSERVATION
Food Supplies
Genes
Biological Control Agents
Natural Products
Pesticides
Medicines
Materials
Environmental Services
Warning Signs
Model Systems for Science
Interesting Wildlife
Future Options
Registered UCI students: view the
slide show for this chapter or download it:
http://darwin.bio.uci.edu:80/~sustain/protected/chap7slides.ppt
ARGUMENTS FOR CONSERVATION
It
is important to be able to clearly define the reasons for believing in
conservation of biodiversity, if we are to justify
it
in the face of increasing threats to species survival. One way to identify the reasons is to look
at what we derive
from
biological diversity, and what we will lose as a result of species extinction.
1.
Food Supplies
Animals.
Only a couple of dozen animal species have been domesticated for food
production. Virtually 100% of the
protein
from domesticated animals consumed by people comes from nine species: cattle,
pigs, sheep, goats, water
buffalo,
chickens, ducks, geese and turkeys.
Fish
are becoming a new kind of domesticated animal through the development of
aquaculture techniques.
Salmon
are now being farmed in large steel/net cages that are moored in various
estuaries and rivers in Norway,
Canada,
Chile, Spain, Scotland, and Ireland.
Shrimp is being grown by aquaculture in many less developed countries
including
Thailand, Bangladesh, Ecuador and the Philippines. Many freshwater fish can be grown in ponds. Israel
and
China already get about half of their fish from aquaculture. The species most commonly grown in existing
facilities
is a cichlid called Tilapia. But there may be many other kinds of wild fish
that could be grown by
aquaculture. The huge, colorful and spectacular tridacna
clam is now being farmed in Palau, in the Pacific island
nation
of Belau, and the farms are a popular tourist attraction.
Plants.
Only a very small proportion of the world's plants have been used for food on a
large scale. About 80,000
are
thought to be edible, but only about 150 are used as human food. As economies
have become more global,
man
has concentrated on fewer species so that today, 90% of the world's food comes
from 15 species. Three of
them
- wheat, corn, and rice - supply two-thirds of this amount. Although there are
over 10,000 species of cereals,
no
new ones have been brought into cultivation during the past 2000 years.
Bananas
and plantains are a staple food crop for millions of people in the tropics, for
example in large areas of
West
and Central Africa, where about 10 million tonnes are produced each year. The genus originated in the Asia
and
Pacific region, where there is still a rich source of diversity of wild
species. Although bananas and plantains
are
best
known as a food crop, the plant is used for many other purposes. Juice from the ripe fruit is used to make
beer, unripe fruit is dried and made into animal
feed, and the peels are used to make an antiseptic poultice for
wounds. The plant fiber is made into a strong paper
(used for bank notes), textiles, string, and for various
handicrafts.
The leaves are used as umbrellas and plates, and for making thatched roofs, for
wrapping food, and
many
other uses. Starch is extracted from the plant and used for production of
glue. In mixed farming systems,
bananas
are used as a shade plant for cocoa, coffee, black pepper and nutmeg, and in
many countries the plant
itself
is used as an ornamental. Seeds from wild species are used for making necklaces
and other ornaments.
Banana
sap can be used as a dye, and banana ash is used in making soap.
The
vast store of species in the tropics is the obvious place to look for new
potential crop plants. The table shows
some
new tropical plant products that might become common sights in the produce
sections of our markets:
POTENTIAL NEW CROPS FROM
TROPICAL AMERICA
Crop
Product
Uvilla
Fruit
Lulo
Fruit
Pupunha
Fruit
Guanabana
Fruit
Buriti palm
Vitamin
C-rich fruit, palm hearts,
oil, starch,
wine, fiber.
Quinoa
High-protein
cereal
Amaranto
High-protein
cereal
Most
of these are already cultivated and the products eaten by local natives. Some
of them have been rediscovered
by
the health-food industry.
At
least 1650 known tropical forest plants have potential as vegetable crops.
"Biopiracy". Unscrupulous investors have been trying to
patent genetic varieties, often when it is clear that they
have
not "invented" anything. For
example, in 1994 the president of the U.S. seed company POD-NERS bought
yellow
beans in Sonora, Mexico. He brought
them home, bred several generations, selecting for yellow seeds. In
1996
the company had produced a "uniform and stable variety with yellow
seeds", and applied for a patent.
In
1999
a U.S. patent (and Plant Variety Protection Certificate) was granted. In 1999 the company was suing
Mexican
bean exporters for patent infringement.
There are 147 other cases of suspected biopiracy: search RAFI
News
for the latest news on this.
2.
Genes
Hybridization
Wild
plants are also important sources of genes that can confer useful properties on
our conventional crops.
The
potato was brought from Peru to Europe in the 15th century, and eventually it
was cultivated as a crop plant all
over
Europe. In Ireland, especially, it became the staple of the diet. But in the
19th century in Ireland a disease of
potatoes
caused a major crop disaster and millions of people to starved to death. A wild
relative of the potato was
found
in Peru, and when it was hybridized with the standard crop plant a
disease-resistant variety was obtained.
A
wild barley plant from Ethiopia provided a gene that protects the $160 million
California barley crop from lethal
yellow
dwarf virus.
Rice
grown in Asia is protected from the four main rice diseases by genes brought in
from a wild species from India.
In
both India and Africa, yields of cassava (tapioca) - one of the most important
root crops throughout the tropics -
were
increased 18-fold because of disease resistance brought in from wild Brazilian
cassava.
The
sugar cane industry in the U.S. was saved from collapse by disease-resistance
genes brought in from wild Asian
species.
A
wild tomato discovered in the Andes has been used to increase the sugar content
of cultivated varieties, increasing
their
commercial value by $5-8 million per year.
Wild
plant species usually have a great deal of genetic variability, so that
markedly different strains can be developed
by
selective breeding from one species. This is an important reason for conserving
not only species, but a good
sampling
of the genetic variability within species - i.e. samples from different
locations, different subspecies, etc.
These
genes from wild species usually have to be brought into the crop by hybridizing
it with the wild species, then
selectively
breeding the hybrids. For this to work, the wild plant has to be closely enough
related to the crop plant
that
it can be hybridized.
About
2.5 million entries are kept in 700 seed banks world wide, but there has been
only limited success in using
these
wild species for crop improvement. Most of the successes have been in disease
resistance, and this is
because
disease resistance is controlled by one or a few genes. This makes it very easy
to transfer into a domestic
species
that can be hybridized to it:
Parents:
RR x rr
Hybrids:
Rr
Backcross (hybrid x
parent):
Rr x RR
Resistant
variety:
RR
But
other characteristics, especially quantitative ones like annual yield or
nutritional quality, are controlled by many
genetic
differences. One wild species may differ from a crop species in some genetic
variations that increase yield
and
others that decrease it, their effects may be masked in the hybrid, and it is
very difficult to capture the desired
genes
in the progeny of the hybrid. Therefore, a new trend in plant breeding is to
try to map all of these genetic
differences
to their positions on the chromosomes. They are called Quantitative Trait Loci
or QTLs. The idea is to
carry
out traditional hybridization and backcrosses, but to track the genetic
differences at the DNA level rather than
just
measuring their effect on the plant (i.e. assess the genotype rather than the phenotype).
This should make it
possible
to exploit much more of the useful genetic variations in wild species.
Transgenic
("Genetically Engineered" or "Genetically Modified") crops
and animals
Another
method of introducing desired genes into a species is by the newly developed
technique of Genetic
Modification
(Genetic Engineering). If a desired
gene from one species has been cloned, then by genetic engineering
it
can be transferred into another species.
The gene has to be first inserted into an individual plant cell, and
this cell
is
then grown into a clone in tissue culture, and the clone can be used to
regenerate an entire transgenic plant.
There
are no serious barriers to this kind of gene transfer - the desired gene can come
from another plant species
or
a different family, or from a bacterium or fungus or animal, or can be
completely synthetic. Surprisingly, the
way
that
genes are copied into RNA, and the RNA translated into protein, are practically
identical in all species, so a
foreign
gene is usually functional.
Furthermore, the protein produced by the foreign gene is also usually a
functional
product. For example, Monsanto is engineering crops
to produce bovine growth hormone, which can be used to
promote
milk production in cattle, using a gene cloned from cattle. Transgenic sheep have been produced that
synthesize
a human protein for use in treating hemophilia.
An
estimated 57 percent of the soybeans and 30 percent of the corn planted in the
U.S. in 1999 were genetically
modified
(GM) (genetically engineered), either to resist pests or herbicides. As of February 1999, at least 64 GM
crop
varieties had been approved in the USA and Canada, 20 in Japan but only eight
in Europe.
Many
kinds of GM crops are being produced:
Insecticidal
crops. Monsanto has produced several GM
crop varieties that make their own insecticide. This is
done
by transferring a gene from the naturally occurring soil bacterium Bacillus
thuringiensis, that encodes an
insecticidal
protein called Bt toxin. Thus:
YieldGard Corn is resistant to corn
borers, corn earworm, fall armyworm and stalk borer.
BollGard Cotton is resistant to the
cotton bollworm.
This
reduces the need for pesticide spraying.
Roundup-ready
crops. Several crops have been modified
to make them resistant to the herbicide "Roundup"
(glyphosate).
This made it possible to use large quantities of Roundup around the crop to
kill weeds without killing the
crop.
Plants
that taste better. Wheat and soy plants have been engineered to contain a gene
from brazil nut plant that
gives
cereals produced from the plant a "nutty" flavor.
Plants
that immunize. Australian scientists
are trying to produce transgenic crops that produce a measles
virus
protein, so that children could be vaccinated by eating special varieties of
rice or lettuce. The initial trials
used
tobacco
plants, since the genetic methods had already been worked out with that
plant. When fed to mice, the
transgenic
tobacco caused the mice to develop antibodies against the measles protein, and
those antibodies then
protect
the mice against measles. Similar
research is being conducted in the U.S. for hepatitis B and cholera, and in
Australia
they hope to produce plants that synthesize an HIV protein.
Terminator
technology. Another modification made
in transgenic crops is called "terminator technology". It is a
genetic
modification that makes the plants grown from the transgenic seed sterile. This was promoted as a way to
prevent
the transgenic crop from hybridizing with other varieties. However, it was seen as a tactic by the seed
companies
to guarantee their markets. In response
to public criticism, Monsanto has announced that it will no longer
use
this technology.
Benefits
of GM crops
Increased
crop yields. Global demand for food is
expected to increase by ~50% in the next 20 years as a result
of
population growth and rising incomes.
Its supporters argue that genetic engineering will contribute
substantially to
increased
crop yields and so help increase the food supply. It can also increase the food value of crops: for
example,
a variety of rape seed (canola) has been genetically modified to contain high
levels of beta carotene, which
the
body can convert into vitamin A. Canola oil from these plants could be made
into a margarine that could provide
enough
beta carotene to prevent night blindness.
Reduced
use of herbicides. The industry
maintains that Roundup-ready crops will help farmers increase yields by
improving
weed control while reducing the total number of sprays needed to control weeds.
Reduced
use of insecticides. Monsanto claims
that their NewLeaf insect-resistant potato requires 40 percent less
insecticide
(for the Colorado potato beetle and aphids that transmit leaf roll virus
disease) than other varieties.
Reduced
soil erosion. When the crops planted
are "Roundup-ready", the fields can be sprayed with Roundup and
the
weeds will be eliminated but the crop will not be affected. This eliminates the need for plowing,
consequently
there
is less erosion and loss of topsoil.
Drought
tolerance. Crops are being produced
that are tolerant of drought, by incorporating genes from east that
improve
tolerance to high sodium.
Criticisms
of GM crops
Some
people object to genetic modification, believing it is unnatural and therefore
wrong. Other criticisms are
based
on more practical considerations:
Health
risks. GM crops may cause allergies.
For example, Wheat and soy plants have been given a gene from
the
brazil nut plant to give them a "nutty" flavor , but this is the same
gene that is responsible for allergies against
brazil
nuts, so the GM cereal may cause the same allergies! There have already been
some examples of mistakes in
identifying
Genetically engineered crop plants. Studies of StarLink (insecticidal) corn
show that it was not
allergenic,
as had been suspected. It was approved
only for animal feed but was found to be contaminating several
corn
products sold to consumers.
Poisoning
of wildlife. Pollen produced by the
plant also contains the toxin, and this may be harmful to animals that
feed
on pollen. In field tests of Bt cotton,
massive mortality of the bees around the test sites was observed.
Evolution
of insecticide-resistant insect pests.
The constant exposure to the insecticide may lead to faster
development
of resistance in the pest insects, than would be the case with an insecticide
sprayed only when
necessary. Bt-resistant insects have already been
discovered in the US and elsewhere.
Contamination
by Insecticide. The insecticide may be released into the soil and have harmful
effects there, or
contaminate
streams. Bt toxin is known to be highly
poisonous to fish.
Genetic
contamination. There are two fears about genetic contamination. First, the herbicide-resistance genes
may
be transferred into other related wild species (e.g. sunflowers) by
hybridization, producing herbicide-resistant
weeds. Second, antibiotic-resistance genes have
usually been used as genetic markers during the production of GM
crops. They have no harmful effect on the plant,
but there are fears that they could be captured by harmful
bacteria,
which would then be resistant to the antibiotic.
Loss
of crop diversity. If the GM crops are successful, farmers are likely to become
too dependent on a small
number
of GM varieties, leading to loss of non-GM varieties that could be have been
useful in the future under
changed
conditions (e.g. drought or attack by presently unknown diseases or pests).
Conflict
of interest. The company responsible for developing Roundup-ready crops was
also selling Roundup.
Terminator
technology was widely believed to have been developed to provide a permanent
market for the seeds,
rather
than to prevent genetic contamination.
65
plaintiffs including Greenpeace, the Sierra Club and the International
Federation of Organic Agriculture Movements
have
filed a suit against the Environmental Protection Agency (EPA), demanding that
the agency withdraw approval
of
all Bt plants and stop approving any new ones until it has done a complete
assessment of their environmental
impact.
Europe
is considering a compulsory labeling system for foods containing products from
genetically engineered
crops.
US biotech companies are frustrated with the resistance to GM crops in European
countries, and claim that
European
governments are imposing non-tariff trade barriers that threaten to undermine
the USA's $60 billion export
trade
in agricultural products. They have
urged the US government to take their case to the World Trade
Organization.
Food
testing. Public fear of GM crops has
led to calls for more complete testing of foods for health effects. But
there
are no good methods available. For example,
to test for health effects of a GM tomato, biologists fed it to
rats
at a rate corresponding to 13 tomatoes per day, and were not able to
demonstrate any difference between
GM and conventional tomatoes - both groups of
rats got sick! This is a general
problem in food safety testing. It is
very
difficult to feed enough of the food product to any test animal to get a useful
result. Instead, the usual
procedure
is to synthesize the suspect chemicals some other way (for example, produce them
in transgenic
bacteria)
and then test the pure compound on animals.
But this approach assumes that we know what chemicals
need
to be tested. We often do not know
enough about how the biochemistry of the GM crop is altered to make
this
a safe strategy.
The
Food and Drug Administration (FDA), which is responsible for certifying the
safety of foods and food additives,
has
no authority over pesticides, so they refer matters concerning Bt to the
EPA. But the EPA has been slow to
recognize
any dangers of GM crops. USDA is responsible for determining whether GM foods
represent plant pests,
and
they have ruled many GM crops harmless.
StarLink,
produced by Aventis CropScience, has been genetically altered to produce a
protein, Cry9C, to repel pests.
Because
the protein may be a human allergen, it was barred from human food in
1998. Since then, Aventis has
asked
EPA to approve StarLink for human consumption. In September 2000, the altered
corn was detected in Taco
Bell
taco shells being sold in grocery stores. Since then it has turned up in
numerous other brands of taco shells, corn
meal
and corn flour. In February 2001, a
group of Iowa farmers filed a class action suit in Des Moines, saying they
were
financially hurt because of consumer fears generated by StarLink.
EPA
Restricts Planting of Biotech Corn | Politicians debate genetically engineered
seeds | Both Sides of
Biotech
Battle Pounce on Butterfly Study | Transgenic Plants and World Agriculture |
Genetically Modified
Trees
Pose Concern | Brief30 | Key FDA Documents Revealing Hazards of Genetically
Engineered Foods |
Rachel's
Environment and Health weekly #685 - Trouble in the Garden | Safety Assessment
Of Genetically
Modified
(GM) Foods | Genetically modified world | Rural Advancement Foundation International
| Biosafety
talks
conclude in surprising accord | Biotech Myths Exposed | PBS - harvest of fear
Value
of genes. Genetic engineering only
works with genes that have been isolated and analyzed at the molecular
level,
and the technology is still dependent on biological diversity to get the genes
in the first place. All of the genetic
variation
present in wild populations is potentially useful for improvement of domestic
animals and plants, and
therefore
should be preserved.
3. Biological
Control Agents
On
many occasions, man has introduced exotic animals or plants that have become
serious pests. Usually, the best
control
methods have been to find the natural antagonists of the species in its
original home. For example:
Prickly
Pear Cactus was introduced into Queensland, Australia, in the 19th century to
provide cattle fences. It grew
out
of control, almost covering 100,000 square miles of land. Eventually a small
moth was discovered in South
America,
whose caterpillars feed on prickly pear. It was introduced to Australia and
quickly decimated the prickly
pear,
and ever since the prickly pear population has been low enough that it is not a
major problem. Now we need
something
like that for Artichoke thistle, Pampas grass and Castor bean.
Introducing
exotic species can, of course, cause problems of its own. Sometimes the organism introduced to control
a
pest can expand its host range and cause serious damage to native
organisms. This happened with a weevil
introduced
to control thistles.
Rabbits
were introduced from Europe to Australia and were a serious pest. They were
brought under control using
the
myxomatosis virus.
Striga. In Africa, sorghum, millet and maize
production can be reduced by as much as 70% by a parasitic weed
called
witchweed or striga. Striga is a
parasitic plant that penetrates the roots of other plants, diverting nutrients
from
them and stunting their growth. Traditional weed control methods are
ineffective in controlling striga but
scientists
have identified an African fungus that effectively eliminates the weed from
cropland.
Cottony
Cushion Scale was introduced here from Australia in the 19th century and almost
wiped out the California
citrus
industry. Entomologists went to Australia and found a small beetle predator,
the Vedalia. This was introduced
and
has kept the scale insect under control ever since.
Other
insect pests including Sugarcane Weevil in Hawaii, Gypsy Moths, Browntail Moths
and Alfalfa Weevils in the U.
S.,
and Rhinoceros Beetles in Mauritius, have been controlled by introduced
parasitic insects.
Scientists
from the University of Illinois recently identified two species of parasitic
wasps that may prove useful in
controlling
stable flies and house flies, two well-known pests in the midwest United
States.
Gypsy
moth larvae have been defoliating huge areas of forest in New England since
they were accidentally
introduced
in 1869. The insecticide spraying programs have wiped out dozens of native
moths and butterflies,
probably
doing more damage than the gypsy moth would have done. Now it is being
controlled by a short-lived toxin
(Bt)
produced by a naturally occurring soil bacterium Bacillus thuringiensis, and a
naturally occurring virus (marketed
as
Gypchek). A lethal fungus is also being tested.
A
new strain of Bacillus thuringiensis might be able to kill more pest species
than previously used strains, without
harming
beneficial insects.
All
of these examples depended on the availability of wild species.
4.
Natural Products
Pesticides.
Many tropical plants produce chemicals that deter herbivores. Tropical
indigenous people have
discovered
many of these plants, and use them as poisons or medicines:
i.Calabar bean was traditionally used as a
poison in West Africa. Chemical studies of this plant led to the
development
of methyl carbamate insecticides.
ii.
Daisy plants (Chrysanthemum cinerariaefolium) were first used centuries ago as
a lice remedy in the Middle East,
and
this led to the discovery of pyrethrum insecticides. The seeds contain a
natural insecticide called pyrethrin, a
generic
name for six related active compounds. It is one of the safer insecticides for
several reasons: it decomposes
rapidly
in sunlight; it has few known effects on mammals; and insects do not develop
resistance to it. It is used on
foodstuffs,
in head lice shampoos, and in many indoor insect sprays. 100,000 tons of
mosquito coils made from
pyrethrum
are sold each year. Scientists have synthesized similar compounds called
pyrethroids, but the chemical
synthesis
produces all geometric isomers of the compounds, many of which are ineffective
and are difficult to
separate
from the active forms. The plant material contains only the active isomers.
iii.
In South America, the natives use an extract of a forest vine to stun fish;
this led to the discovery of rotenone, a
biodegradable
insecticide.
iv.
The bacterium Bacillus thuringiensis produces toxic proteins that kill certain
insects but are apparently harmless to
humans.
These are being produced and marketed as biopesticides. And Monsanto has
engineered cotton plants that
produce
their own protein insecticide.
v. The Neem tree, in India, has been found to
be a source of the insecticide azadirachtin, as well as fungicides,
spermicide,
and agents potentially valuable in birth control such as materials that prevent
implantation or cause
abortion.
The tree has been used in traditional agriculture, medicine and cosmetics for
centuries. However, recently
companies
from industrialized countries have been seeking patent protection, and 90
patents have been granted
worldwide
for "inventions" of products from Neem. A coalition or organizations has been fighting patenting of
materials
already in traditional use (biopiracy), and in 2000 they achieved their first
victory in persuading the
European
Patent Office to revoke a patent from USDA and W.R. Grace on Neem tree
fungicide on the basis that the
product
was already being used traditionally (in India) before the Company patented
it.
Other
tropical plants have been found to be toxic to leafcutter ants, mosquitoes, and
other insects, and could lead to
the
discovery of other pesticides.
USDA
- biological control | Gypsy Moth management | Gypsy Moth in North America |
Neem tree patents |
More
neem tree patents | Aussie natives beat the fungal rotters, ENN Newswire --
August 28, 1997
MEDICINES FROM
WILDLIFE
from a
list of 117
Purpose
Drug
Source
Traditional use
Immunosuppressant
Cyclosporin
Fungus,
Tolypocladium
inflatum
Contraceptives
Steroids
Fungus, Rhizopus nigricans
Anti-inflammatory
Cortisone and
prednisone
Fungus, Rhizopus nigricans
Cholesterol lowering
Lovastatin
Fungus, Aspergillus terreus
Painkillers
Aspirin
Codeine
Morphine
Cocaine
Tetrodotoxin
Willow
Opium poppy
Opium poppy
Erthroxylum coca
Centr. Amer. frog
+
+
+
+
+
(trance-inducer)
Antimalarial
Quinine
Cinchona (coffee
family)
+ (Indian fever bark)
Amebicide
Emetine
Cephaelis
ipecacuanha
+
Heart stimulants
Digitalis
Ouabain
Foxglove
Strophanthus
gratus
+
+ (arrow poison)
Muscle
relaxant
Tubocurarine
Chondrodendron
tomentosum
+ (arrow poison)
High Blood
pressure
Reserpine
Rauwolfia
serpentina
+
Glaucoma
Pilocarpine
Pilocarpus
jaborandi
+
Medicines.
The potential for discovering medicinal compounds in wild organisms is
enormous, and provides one
of
the most powerful arguments for conservation of biological diversity. This is
especially true of tropical forests.
The
pharmaceutical industry is much more dependent on natural products than is
generally realized. About a quarter
of
all prescription drugs are taken directly from plants or are chemically
modified versions of plant substances, and
more
than half of them are modeled on natural compounds. About 121 prescription drugs are derived from higher
plants.
These include morphine, codeine, quinine, atropine, and digitalis. Yet fewer
than1% of rainforest plants have
been
tested.
Why
should plants make medicines? Wild plants have been evolving chemical defense
mechanisms for millions of
years.
The chemicals that have evolved are highly specific toxins that attack
herbivores at various different points in
biochemical
pathways. Although the chemicals are often toxic, sometimes if they are
delivered in the right way or in
the
right dose, or altered chemically, they can be used to attack disease-causing
agents or even cancer cells.
Many
of these chemicals are derived from plants that had been used in traditional
medicine. For example, Peruvian
Indians
had a cure for malaria; they used an extract of the bark of the Cinchona tree,
and this led to the discovery
and
use of quinine as an antimalarial treatment. Of the 121 drugs mentioned
earlier, 74% were identified through
native
folklore.
A
Japanese company was recently awarded a patent on a chemical derived from the
Congorosa bush, a plant that
is
native to Uruguay. The native people
have known for centuries that the plant can be used to combat
inflammation
and as a stomach and liver analgesic, so they are very much opposed to paying a
fee to a Japanese
company
for the right to continue these uses.
THE
STATUS OF NATURAL PRODUCTS RESEARCH IN MALAYSIA
Natural
products isolated from higher plants and microorganisms
Hawaiians
Replant Sugar Fields with Joy-Generating Kava
Even
compounds produced by insects and other invertebrates may be useful. Recently a
protein isolated from the
salivary
gland of a biting sandfly was shown to have a very powerful vasodilation effect
(this facilitates blood feeding
by
the insect when it is injected into the host).
ANTI-CANCER DRUGS
Drug
Source
Traditional use
Cantharidin
Chinese Blister beetle
+
(abortifacient)
Etoposide,
podophyllotixin,
teniposide
Podophyllum peltatum
+
(snake bites,
weakness, condyloma,
lymphadenopathy, tumors)
Monocrotaline
Crotalaria spectabilis
+
(skin cancer)
Vincristine,
Vinblastine
Rosy periwinkle
+
(diabetes)
Taxol
Yew (Taxus brevifolia)
_
i. Cancer drugs. The rosy periwinkle was
used in Cuba, the Philippines, and South Africa for the treatment of
inflammation, rheumatism, and diabetes.
In the late 1950s, vincristine and vinblastine were isolated from the
periwinkle plant by Eli Lilly scientists
and these chemicals were shown to have anti-cancer effects. Treatment
with these drugs has increased the
chances of remission to 99% in childhood leukemia and to 70% in
Hodgkin's disease. Global sales of
vincristine and vinblastine earn the Eli Lilly Company about $100 million each
year.
In 1986, the National Cancer Institute
started a new, extensive plant collection and screening program and has
tested (on cultured cells) 35,000 species
of higher plants as well as other organisms for anti-AIDS and
anti-cancer activity. As of 1991, over
800 had shown some anti-HIV activity and 60 had shown anti-cancer
activity (the HIV screens have been given
higher priority). Plants used as medicines or toxins by forest people
were 2-5x more likely to be active in
these assays as other plants. This is a very preliminary result, and many
more tests have to be done before any of
these compounds will go into clinical trials. NCI estimates that of
every 10,000 extracts tested, fewer than
10 will reach clinical trials. NCI is also supporting botanical exploration,
research and training to increase the
number of species to be tested. The collections have identified more than
40 new species of plants. NCI requires
that if a pharmaceutical company receives a patent license, they have
to share a percentage of the royalties
with the country where the sample originated.
Chemists have devised ways of
synthesizing many of the medicinal compounds found in plants. But it is usually
(in about 90% of cases) cheaper to
extract the natural product. In spite of this, pharmaceutical firms in the
U.S. are doing very little to discover
new drugs from higher plants. They are concentrating on other
approaches; for example, using
supercomputers to design new molecules.
An exception is Shaman Pharmaceuticals, a
company set up specifically to identify and obtain medicinal
compounds from tropical plants. Their
program involves a serious effort to obtain not only materials but also
knowledge from the people of the rain
forest; they spend a lot of time interviewing forest people about
medicinal uses of plants, then give much
higher priority to testing those that have folk uses. They are
screening for antiviral, antifungal, and
sedative/analgesic activity. Out of the first 58 species screened, they
found that 60% had activity in one of
their screens, and 74% of their active samples correlated with the
original ethnobotanical use. This is a
much higher "hit" rate than then NCI rate, perhaps because of the
different activities being screened for,
and perhaps because they make greater use of ethnobotanical
knowledge. This company is also dedicated
to developing nondestructive harvesting methods and in providing
benefits from any discoveries to the
indigenous people who are the primary sources of the inventions. Merck &
Co. have also set up an agreement with a
research institute in Costa Rica to screen samples from
micro-organisms, plants and insects from
that country's forests. The institute will earn a share of any royalties
on the sale of products derived from the
project.
In 1982, the TRAMIL (Traditional Medicine
for the Islands) research network was launched in the
Dominican Republic to provide
scientifically proven alternatives to patent drugs, which are becoming scarcer
and more expensive due to increasing
poverty and dwindling foreign currency reserves. The network — which
recognizes that many rural people are
more familiar with medicinal plants — aims to ensure the safety,
efficacy, and accessibility of natural medicines. In this manner, TRAMIL
hopes to preserve the diversity of
plant species and indigenous
knowledge.
In 1998, six patent applications on the medicinal
properties of turmeric were successfully challenged by the
Indian Council of Scientific and
Industrial Research. The U.S. patent
office ruled that turmeric's medicinal
properties were part of the traditional
Indian knowledge base and were therefore not patentable.
Native Plants: Echinacea
The Pacific Yew tree, a rare and
slow-growing tree in the Pacific Northwest, is the only source of a drug called
taxol, which appears to be very effective
in treating ovarian cancer and has great promise for treating breast
cancer as well. Each year, about 20,500
women are diagnosed with ovarian cancer and about half that
number die from it. But it takes six
Pacific yew trees to extract enough taxol to treat one patient. The National
Cancer Institute has enough available to
treat about 300 patients-not even enough to complete clinical trials.
The yew tree is found only in old-growth
forests, so it has now become a potential problem, along with the
spotted owl, in trying to save these
forests. Recently, chemists found a way of synthesizing taxol, so
eventually the trees will not have to
beharvested.
The taxol story will hopefully have a
happy ending, and it teaches us that the forest (and other natural
habitats) should be considered a source
of knowledge about medicines, rather than a source of the medicines
themselves.
ii.Antibiotics. Antibiotics are generally
isolated from fungi (e.g. penicillin) or bacteria (e.g. erythromycin).
However, a small group of antibiotics comes from marine animals-
mimosamycin, that comes from a
nudibranch (sea slug) and a sponge.
ANTIBIOTICS
(about 1,000
now known )
Antibiotic
Source
Penicillin
Cephalosporin C
Griseofulvin
Bacitracin
chloromycin
erythromycin
streptomycin
tetracycline
mimosamycin
Penicillium chrysogenum
Cephalosporium acremonium
Penicillium griseofulvum
Bacteria
Bacteria
Bacteria
Bacteria
Bacteria
Nudibranch, Sponge
Materials.
Many organisms have evolved materials whose unusual physical properties may
make them useful.
They
may be obtained from the wild or, better, copied by biochemists. In many cases,
finding one useful material
may
lead to the discovery of many more, with subtle differences in physical
properties, from related organisms.
i. Fibers. Silkworm silk has been used
for hundreds of years in production of fabrics. Spider silk, which
is chemically very similar to silkworm
silk, comes in many different varieties (some species make seven
different kinds - see slide) and has
5-10x the tensile strength of steel and some very unusual elastic
properties. It has been used on a limited
basis for fishing nets and for wound dressings, and for cross
hairs in optical instruments. The genes
for spider silk have been placed in bacteria, and the bacteria then
make the silk protein. However, they make
it in a solution, and this has to be extruded (forced through
a small orifice at high pressure) to
force the protein molecules to line up into a fiber. This has the
potential to be strong enough to make
bullet-proof vests and lightweight materials for the aerospace
industry.
ii. Coatings. Shellac, a wax produced by
insects that is harvested by hand from trees in India. 4 million
pounds/year are harvested and used in
varnishes, paints, stiffeners and other uses. Some related
species of insects in the southwestern
U.S. make colored waxes that were used by the Indians to
waterproof and decorate baskets and to
repair pottery.
The cuticles and eggshells of insects,
crustaceans, and many other animals, and the seed coats and
other protective layers on plants may
have useful properties as waterproof coatings for other materials.
Chitin (the carbohydrate part of cuticle,
extracted from shrimp shells) is already used to make wool
shrink-resistant.
Keratins (the protein of feathers and hair)
is used as a coating for pills so that they survive the acid
stomach but then release their contents
in the alkaline intestine.
iii. Adhesives. Casein, a protein from
milk, is already used extensively in glue manufacture as well as in plastics
and paints.
At least two companies are now marketing
a glue based on the adhesive used by marine mussels to hold
themselves on rocks. This kind of glue
will stick to animal tissue as well as to metals and other materials. It
might be useful in surgery and in other
places where glue needs to function in a wet environment or needs to
join dissimilar materials like metal and
bone. One company is extracting the glue directly from a gland in the
mussel, the other is synthesizing a glue
based on the composition of the natural adhesive. Unfortunately, the
natural material is not well understood.
However, there are hundreds of different kinds of mussel, and there
may be many different versions of the glue
to investigate.
iv. Biopolymers, especially moldable
polymers, similar to plastics made chemically, have been produced in
bacteria and theoretically could be
produced in plants, so that the material could be grown as a crop.
v. Oils. About 20% of the petroleum used
in this country is used for non-fuel purposes such as plastics,
fertilizers, lubricants, and adhesives.
The majority of these substances can now be synthesized from plant
products. In fact, about 3 million tons
of vegetable fats and oils are already used in these processes annually.
Further development of these industries
could help in reducing our dependence on non-renewable fossil fuels.
There are several promising tropical oil
plants in South America, including:
Patuá palm. The fruit produces an oil
that is almost identical to olive oil, and is rich in protein as well.
Babassú palm. Produces a coconut-like
fruit rich in oil and protein. The tree grows well in deforested
areas.
Fevillea vine. Seeds have an
extremely high oil content.
Another very important plant is Jojoba, a
desert plant of the southwestern United States and northern Mexico
that produces a "liquid wax"
(chemically different from an oil) that is almost identical to sperm whale oil,
is very
useful as a heat-resistant lubricant and
has many other potential uses. Another desert plant, guayule, has a
very high content of natural rubber and
could help to relieve the dependence of this country on rubber grown
in southeast Asia.
Oil from the seed of India's Pongamia
pinnata tree is being used as a substitute for diesel in electricity
generation in rural areas of the
country.
Enzymes. Some of the bacteria-like
organisms found near submarine hot vents (Archaea) can live at
temperatures as high as 113oC and may be
useful in the production of enzymes that are stable at high
temperatures (for use in washing
machines, for example).
Biomimetic materials science is the name
given to attempts to mimic the materials found in nature. Much of it
is funded by the Navy and the Air Force,
because of the potential importance of lightweight but strong
materials in aerospace engineering, and
of underwater glues and coatings in marine engineering. It is
necessary to understand not only the
chemical makeup of the biological materials, but also the organization of
different components within the material
(e.g. calcite and proteins in sea urchin skeleton, or carbohydrate and
protein in cuticle), which in nature is
controlled by the cells producing the material.
5. Environmental Services
Wild organisms carry out many functions
in the environment that are vital to us, and that would be very
difficult to do ourselves. Bees pollinate
about a trillion apple blossoms each year in New York State.
Carpenter bees pollinate Brazil-nut
trees. Bats pollinate wild bananas (not the cultivated ones that are
parthenocarpic), breadfruit, guava and
durian (Malaysian fruit). Wild micro-organisms biodegrade much of our
garbage as well as fallen leaves and
other dead animal and plant matter. Earthworms turn over soil and keep it
aerated. Soil bacteria turn nitrogen into
nitrate fertilizer. Plants use up carbon dioxide and produce oxygen,
thereby slowing global warming due to
CO2.
A few decades ago, the water in the
Chesapeake Bay was clear because oysters were filtering out particles at
a rate estimated to be the equivalent of
the entire volume of the bay every three days.
Because the oysters
have been overharvested (99% gone) they
are no longer able to keep up with the accumulation of silt and
other particulates.
All of these services, and many more
besides, are provided free of charge and usually taken for granted until
they stop.
ENVIRONMENTAL
SERVICES
Service
Organism
Pollination
Biodegradation
Soil
aeration
Fertilization
CO2 - 02
exchange
Water storage
bees, bats
micro - organisms
earthworms
soil bacteria
plants
plants
Bioremediation (=phytoremediation if it
is done by plants) refers to the use of organisms to clean up toxic
wastes. Some plant species that live
naturally on soils that are rich in heavy metals have evolved biochemical
mechanisms for extracting those metals
from the soil and accumulating them to very high levels in their
tissues. They are called
hyperaccumulators. Some of them accumulate so much metal that it makes up 5%
of their weight. This makes them toxic to
insects, so it has probably evolved as a defense mechanism. Plants
have been found that hyperaccumulate
copper, nickel, lead, cadmium, chromium, zinc, cobalt, mercury and
selenium, so they are being planted on
toxic waste sites where they remove the toxic metals from the soil.
They can be burned in order to recover
the metal in cases (copper and nickel) where the metal is valuable.
With less valuable metals such as lead,
the hyperaccumulating plants are much easier to dispose of than
contaminated soil.
A simple use of phytoremediation has been
used in California's San Joaquin Valley, where there is a problem
with high levels of selenium in the soil.
Growing mustard plants on the contaminated soil reduced selenium
levels by 50% at depths down to 1m.
Other sites where this technique is being
used include abandoned mines (zinc and lead); military sites (lead and
cadmium); municipal waste dumps (copper,
mercury, lead); and sewage dumps (all of these metals).
Phytoremediation is potentially much more
effective and less expensive than current methods which consist
mainly of excavation and reburial.
Some of the hyperaccumulating plants are
difficult to grow and do not produce much biomass. Scientists are
therefore exploring ways of transferring
the genes responsible for hyperaccumulation into common crop plants
that would not have these drawbacks.
Poplar trees may remove contaminants, ENN
Daily News -- 9/30/98
Microbe munches MTBE contamination, ENN
Daily News -- 10/13/98
In a paper published in Nature in May
1997, a group of 13 ecologists, geographers and economists estimated
the economic value of these environmental
services at between $16 and $54 trillion per year. This estimate is
based on the cost of artificially
providing the same services. The services they evaluated included food
production, raw materials, recreation and
water supply, regulation of climate and atmospheric gases, water
cycling, erosion control, soil formation,
nutrient cycling and the purification of wastes. Also read the discussion
of this paper.
Ecosystem Services: Benefits Supplied to
Human Societies by Natural Ecosystems
6. Warning Signs
"Miners use canaries to warn them of
deadly gases. It might not be a bad idea if we took the same warning
from the dead birds in our
countryside" (H.R.H. the Duke of Edinburgh at the Wild Life Fund dinner,
about
1963 in reference to DDT). Today, we
might take the same warning from the forest dieback, the dead sea
lions and dolphins on our beaches, and
the missing amphibians. (See Lecture 14 for examples of the effects of
chemical pollutants on wildlife.) If the
environment is killing animals and plants, it might eventually kill us too.
Pesticide levels in human milk are enormous.
If we were egg-laying mammals we might be suffering from
eggshell thinning caused by DDT by
now.
The necessity of looking to wildlife
species for warning signs becomes more evident when one considers that
for 71 percent of the 3,000
highest-volume chemicals in the U.S. economy no human health-effect screening
has ever been conducted. A 1984 report released by the National
Academy of Sciences' National Research
Council documented a lack of "even
minimal" health screening tests for 78 percent of high-production-volume
chemicals in the U.S. In July of 1997, the Environmental Defense
Fund released a study entitled "Toxic
Ignorance" that pointed to the lack
of improvement in screening over the last 13 years. In conjunction with
the report's release, the EDF called for
commitments from the chief executive officers of the 100 top chemical
manufacturers in the U.S. to complete
preliminary health screening tests on each company's top-selling
chemicals before the year 2000, and
disclose the results to the public.
According to the EDF study, the testing
requested would cost between 1/10 of a
cent to 2/3 of a cent per dollar of profit for the top 100 US
companies, which made profits of $29.4
billion last year on $230.5 billion of chemical sales. In the meantime,
the effects of these chemicals on
wildlife, and on humans, remain unknown.
7. Model Systems for Science
Wild species provide raw material for
basic research. The object of basic research is simply to understand the
natural world. Even though it often leads
to material benefits, and is justified that way, the motivation is simply
the challenge to know as much as possible
about the natural world, and to understand how both living and
non-living things work.
8. Interesting Wildlife
Wildlife is worth conserving because it
is interesting, beautiful, spectacular, or contributes to landscapes that
are interesting, beautiful, or
spectacular. Wild animals and plants provide inspiration not only to biologists
but
also to millions of naturalists,
explorers, painters, photographers, writers, poets and musicians. After Aldous
Huxley read Rachel Carson's Silent Spring
(about the loss of songbirds due to DDT), his comment was that
"we are losing half the
subject-matter of English poetry".
Enjoying wildlife is far from being
restricted to poets, however. According
to a survey conducted for the U.S.
Fish and Wildlife Service, 77 million
Americans participated in wildlife-related recreation in 1996. During that
time, they spent $108 billion compared to
only $81 billion on cars. Preserving
the environment is healthy for
the economy as well as for the soul.
John Muir, one of the founders of the Sierra Club, valued
wilderness and wild creatures for their aesthetic
qualities. He managed to convince
President Theodore Roosevelt, the hunter, that our most beautiful areas
should be protected, simply for aesthetic
reasons. His work led to the establishment of Yosemite National Park
and many other protected areas.
These arguments justify saving subspecies
as well as species. Some of them justify preserving abundance as
well as existence of a species. Of
course, ecosystems are interesting too, and according to this view they
should also be conserved. Some of the
most interesting aspects of animal life (social behavior, migration, etc.)
occur only in the wild, not in zoos. So
this argument favors conservation in the wild.
9.Future Options
We do not know what our value systems
will be in the future, or what the value systems of our successors will
be. Perhaps they will need vast
quantities of some species that we now consider insignificant or even harmful.
Many of the natural sources of medicines
are, in fact, poisonous. Nobody could have predicted that bread
mold would be the source of one of the
most useful antibiotics; that armadillos would have been useful in
medical research because they are the
only experimental animal that can be infected with leprosy; or that the
Madagascar periwinkle would be a source
of an antileukemic drug, or that a heat-loving microbe living in a hot
spring at Yellowstone National Park would
provide a key ingredient in the DNA fingerprinting work was so
important in the O.J. Simpson trial.
The main reason for preserving not only
species but also genetic variability of not only wild species but also
domesticated ones (and humans!) is so that we, and the other
animals and plants on the planet, can adapt to
unforeseen changing circumstances.
A relevant question that is now being
asked is whether we should destroy the last remaining stocks of the
smallpox virus. They are being kept in a
freezer pending review of a decision made to destroy them in 1999.
In the future we may find new reasons for
keeping ecosystems, not just species, alive. We could not learn
about medicinal plants from chimpanzees
if they are in a zoo - they have to be in an intact environment in the
wild.
By allowing species to become extinct and
by destroying ecosystems we cut off options that we are not
capable of imagining; the responsible
course is to keep as many options open as possible.
For additional reading, see "Do We
Still Need Nature? The Importance of Biological
Diversity".Biodiversity and its
value (Biodiversity Series No. 1)
Biodiversity and Ecosystem Functioning
Economic Value of Biodiversity
INTERNATIONAL SOCIETY FOR ECOLOGICAL
ECONOMICS
Biodiversity and its value
(Biodiversity Series No. 1)
Legal, ethical and conservation issues
related to uses of biodiversity
The search for agricultural and medicinal
uses for the world's biodiversity is not without controversy. Legal and
ethical issues surrounding the sharing of
genetic resources and the profits realized from them remain
unresolved. The United Nations Convention on Biodiversity addresses many of
these issues and has been
ratified by 170 countries. Some countries, including the United States,
still refuse to sign the agreement,
primarily because it contains clauses requiring
profits from biodiversity be shared with the species' country of
origin.
Finding useful drugs in wild plants and
animals can be a mixed blessing.
According to the World Health
Organization the global trade was worth
about $500 million a year in 1980, but by 2000, the larger European
market alone may reach $500 billion. A 1998 study by TRAFFIC, the wildlife trade
monitoring program of
World Wildlife Fund and the World
Conservation Union, identified 102 medicinal plant species (including the
frankincense tree) and 29 medicinal
animal species (including the green turtle, African rock python, and black
rhinoceros) as priorities for early
conservation and management action.
Quiz: What do Christmas trees,
stone-washed jeans, coca cola and soy sauce have in common? They all
depend on an under-appreciated part of
our biodiversity (click to answer!)