Unit 3 Background: Introduction to Biodiversity
Ecology: A Closer Look at the World We Live In
Dedicated
to Reducing
Pesticides
The lessons, activities and resources listed in this section will help create a window on the worl d to increase participants understanding of
our complex environment and critical issues that all nations and people
face. With over 6 billion people living on the Earth, about 80 million
more added each year, the population growth is exerting tremendous
stress on the environment.
The destruction of animal habitats due to human activities worldwide is
by far the biggest cause of species extinction. Species are disappearing at the alarming rate of an estimated 30 to 75 per day.
Overconsumption of resources by people who live in industrialized
countries such as the United States, Japan, and France is a major problem facing future generations. Fossil fuels, lumber, soil, water, and
other resources are being used by a fraction of Earth s population, but
they are being consumed at a rate faster than Nature can replenish
them. Pollution from human activities threatens plants and animal habitats, streams and oceans, forests and farms. Insecticides poison our
waters while cars and power plants foul the air, both causing permanent global changes.
These activities will help to provide participants with an awareness,
appreciation, and understanding, and hopefully, a commitment to care
about the environment. They can encourage creativity and originality in
helping to solve some of these critical issues.
Administer the Biodiversity Basics Quizmo
INTEGRATED PEST
MANAGEMENT
Unit 3 Background: Introduction to Biodiversity
Biodiversity Basics Quizmo
Biodiversity Basic Presurvey of Student Knowledge
Directions: Administer this survey prior to teaching the lessons.
You inhabit the Earth with many other living plants and animals. How
much do you know about the diversity of living things with which you
share the planet?
1. How many species have scientists identified so far?
a. 100,000
b. 1,700,000
c. 5,000,000
d. 1,000,000,000
2. The rainforests of the world have been called Nature’s Medicine Chest.
What percent of all prescription drugs come from this unique habitat?
a. 10%
b. 30%
c. 50%
d. 70%
3. Scientists think that many potential drugs are waiting to be discovered.
What fraction of prescription drugs used today are originally derived from
plants?
a. 1/4
b. 1/3
c. 1/2
d. 1/8
4. One of the biggest threats to the Earth’s biodiversity is:
a. alien or introduced species
b. overpopulation
c. pollution
d. all of the above
5. Alien species have caused environmental problems because:
a. they move into new locations and pollute
b. they overpopulate a habitat because they may not have as many
predators
c. they drive out existing native species
d. they do not fit in with the landscape
page 2
Unit 3 Background: Biodiversity Basics Quizmo
Unit 3 Background: Introduction to Biodiversity
Biodiversity Basics Quizmo
(continued)
6. While many species of creatures may appear ugly and scary, some have
proven to be invaluable. Vampire bats are such creatures because scientists have found a way to:
a. freeze their blood for transfusions
b. use their eyes to study vision and blindness
c. use them to study navigation
d. use their saliva to dissolve blood clots in humans
7. Humans, and for that matter, all mammals and vertebrate species, are outnumbered by what group?
a. fish
b. amphibians
c. protozoans
d. insects
8. Which of the following environments cannot support life?
a. deep-sea hydrothermal vents where temperatures can reach 662…
Fahrenheit or 350… Celsius
b. in the frigid ice of Antarctica
c. boiling sulphur spring where the heat can reach 212… Fahrenheit or
100… Celsius
d. none of the above
9. What is the main reason for the loss of biodiversity on the planet?
a. pollution
b. overpopulation
c. habitat loss
d. introduced species
10. If you had to research the number of species in the United States that are
endangered, how many species reports would you write?
a. 152
b. 615
c. 517
d. 1,082
Unit 3 Background: Biodiversity Basics Quizmo
page 3
Unit 3 Background: Introduction to Biodiversity
Biodiversity Basics Quizmo
(continued)
11. An entomologist studying insect life in the rainforests of South America
discovered that a single tree can be the home of over __________ species
of insects.
a. 10
b. 100
c. 500
d. 1,000
12. Horseshoe crabs have been around since the days of the dinosaurs.
One liter of their blood is worth up to $8,000. Why?
a. Their blood is used for transfusions.
b. It contains special cells that can be used to test for bacterial contamination.
c. The shells are ground up and used as an agent to increase blood flow
in people with congestive heart failure.
d. None of the above
13. Insect damage costs farmers huge crop losses and, therefore, lost profit.
One of the major techniques farmers use to protect plants without using
poison is:
a. to introduce insects such as the ladybug and praying mantis to eat
pests
b. to use soap and water washes
c. to add vitamins to the soil
d. to rotate crops
14. Cockroaches have survived for millions of years by being able to:
a. coat their bodies with a film of oil that helps them squeeze through
cracks thinner than a match head
b. be hearty and resilient. Even after being decapitated, the cockroach
head responds to stimulation for 12 hours.
c. develop defense mechanisms like the hissing cockroach from
Africa uses when it scares predators by blasting air out of its spiracles
d. all of the above
15. The most important reason that mold is important to Earth’s biodiversity is:
a. it is an ingredient in antibiotics
b. it is great in salads
c. it is terrific on pizza
d. it lives in a world where it helps biodegrade dead things
page 4
Unit 3 Background: Biodiversity Basics Quizmo
Unit 3 Background: Introduction to Biodiversity
Biodiversity Basics Quizmo Answer Key
Biodiversity Basic Presurvey of Student Knowledge
You inhabit the Earth with many other living plants and animals. How
much do you know about the diversity of living things with which you
share the planet?
1. How many species have scientists identified so far?
a. 100,000
b. 1,700,000
c. 5,000,000
d. 1,000,000,000
2. The rainforests of the world have been called Nature’s Medicine Chest.
What percent of all prescription drugs come from this unique habitat?
a. 10%
b. 30%
c. 50%
d. 70%
3. Scientists think that many potential drugs are waiting to be discovered.
What fraction of prescription drugs used today are originally derived from
plants?
a. 1/4
b. 1/3
c. 1/2
d. 1/8
4. One of the biggest threats to the Earth’s biodiversity is:
a. alien or introduced species
b. overpopulation
c. pollution
d. all of the above
5. Alien species have caused environmental problems because:
a. they move into new locations and pollute
b. they overpopulate a habitat because they may not have as many
predators
c. they drive out existing native species
d. they do not fit in with the landscape
Unit 3 Background: Biodiversity Basics Quizmo Answer Key
page 5
Unit 3 Background: Introduction to Biodiversity
Biodiversity Basics Quizmo Answer Key
(continued)
6. While many species of creatures may appear ugly and scary, some have proven
to be invaluable. Vampire bats are such creatures because scientists have found
a way to:
a. freeze their blood for transfusions
b. use their eyes to study vision and blindness
c. use them to study navigation
d. use their saliva to dissolve blood clots in humans
7. Humans, and for that matter, all mammals and vertebrate species, are outnumbered by what group?
a. fish
b. amphibians
c. protozoans
d. insects
8. Which of the following environments cannot support life?
a. deep-sea hydrothermal vents where temperatures can reach 662…
Fahrenheit or 350… Celsius
b. in the frigid ice of Antarctica
c. boiling sulphur spring where the heat can reach 212… Fahrenheit or
100… Celsius
d. none of the above
9. What is the main reason for the loss of biodiversity on the planet?
a. pollution
b. overpopulation
c. habitat loss
d. introduced species
10. If you had to research the number of species in the United States that are
endangered, how many species reports would you write?
a. 152
b. 615
c. 517
d. 1,082
page 6
Unit 3 Background: Biodiversity Basics Quizmo Answer Key
Unit 3 Background: Introduction to Biodiversity
Biodiversity Basics Quizmo Answer Key
(continued)
11. An entomologist studying insect life in the rainforests of South America
discovered that a single tree can be the home of over __________ species
of insects.
a. 10
b. 100
c. 500
d. 1,000
12. Horseshoe crabs have been around since the days of the dinosaurs.
One liter of their blood is worth up to $8,000. Why?
a. Their blood is used for transfusions.
b. It contains special cells that can be used to test for bacterial contamination.
c. The shells are ground up and used as an agent to increase blood flow
in people with congestive heart failure.
d. None of the above
13. Insect damage costs farmers huge crop losses and, therefore, lost profit.
One of the major techniques farmers use to protect plants without using
poison is:
a. to introduce insects such as the ladybug and praying mantis to eat
pests
b. to use soap and water washes
c. to add vitamins to the soil
d. to rotate crops
14. Cockroaches have survived for millions of years by being able to:
a. coat their bodies with a film of oil that helps them squeeze through
cracks thinner than a match head
b. be hearty and resilient. Even after being decapitated, the cockroach
head responds to stimulation for 12 hours.
c. develop defense mechanisms like the hissing cockroach from
Africa uses when it scares predators by blasting air out of its spiracles
d. all of the above
15. The most important reason that mold is important to Earth’s biodiversity is:
a. it is an ingredient in antibiotics
b. it is great in salads
c. it is terrific on pizza
d. it lives in a world where it helps biodegrade dead things
Unit 3 Background: Biodiversity Basics Quizmo Answer Key
page 7
Unit 3 Background: Introduction to Biodiversity
Biodiversity
Diversity is a fundamental characteristic of life itself. Biological diversity or biodiversity is an expression used to describe the richness or variety of living organisms found in an area or type of environment, including both the number and frequency of genes, species and ecosystems.
Biodiversity is usually divided into three fundamental categories:
* Genetic diversity: the genetic variation within each species
* Diversity of species: the different species in a given area or
habitat
* Diversity of ecosystems: the natural environment comprises
many different types of habitats
There are limits as to how much any biological resource can be exploited, and in many cases mankind is exceeding those limits. The elimination or change of habitats is the leading cause of loss of biodiversity.
The introduction of non-native or alien species to the habitat also causes
severe problems, like diseases and increased competition. Overhunting
and overharvesting, in addition to the factors already mentioned, may
also cause extinction of some species. Others may become rare or
disappear from the habitats locally.
Human encroachment, like urban settlements, roads, clearcutting of
forests, dams and mass tourism, tend to fragment the habitats, making
it difficult for species needing large, contiguous areas of habitat to
survive.
page 8
Unit 3 Background: Biodiversity
Unit 3 Background: Introduction to Biodiversity
Biodiversity Background
Some specific facts include:
* Recent quantitative rankings indicate that alien species are second only to habitat degradation as today’s leading cause of loss of
biodiversity.
* Between 1906 and 1991, 79 alien species alone caused $97 billion
dollars in damage to agriculture, industry, and health in the
United States. At least 4,500 species of alien origin have established free-living populations in the United States. Around 15% of
these species cause severe harm.
* Weeds have invaded approximately 17 million acres of public
rangeland in the west.
* Calculating that the average weed spreads by 14 percent annually, weeds are expanding into 550 million acres of federal lands at
roughly 4,600 acres per day.
* One characteristic of a successful invader is the ability to reproduce in large numbers. For example, one yellow star thistle plant
can produce 150,000 seeds. One mature purple loosestrife plant
produces more than 2,500 flowers with 100 seeds per flower,
equal to 250,000 seeds per plant per year. This plant is a perennial plant, producing these extremely high amounts of seed every
year. One acre of purple loosestrife is estimated to produce 1 billion seeds per year.
* Global changes may promote invasions and alter the fate of
invasive species.
(Cambridge Educational 1999)
Unit 3 Background: Biodiversity Background
page 9
Unit 3 Background: Introduction to Biodiversity
Why is Our Wildlife in Trouble?
Today, species are disappearing at an extraordinary rate — an estimated
30 to 75 species a day. In most cases, these extinctions are the result of
human activity. One way to talk about the major threats to biodiversity is
by remembering the acronym HIPPO.
H
abitat loss. A wetland is filled in for housing. A rain forest is cut down for
subsistence farming. Worldwide, loss of habitats is by far the biggest cause of
species extinction. As part of the effort to save habitats all over the planet, scientists have identified the Global Zoo — an approach to conserving the world s
most critical ecoregions ( * see A Blueprint for Learning, page 3).
Introduced species. Animals and plants deliberately or accidentally intro-
duced into an area can wreak havoc on local species not equipped to deal with
them. Introduced species, also called alien, exotic, or non-native species, often
do not have natural predators or diseases to control their populations in the
new area. And native species often have no defenses against introduced
species or the diseases they carry. For example, mongooses brought to the
Virgin Islands, in the Caribbean Sea, to control rats have also decimated native
populations of birds and snakes.
Pollution. A by-product of many human activities, pollution threatens count-
less species of plants and animals. Logging of hillsides may cause soil erosion
and the pollution of streams and rivers through runoff of silt. Insecticides and
oil spills are other sources of water pollution. Cars and power plants release
carbon dioxide into the atmosphere, polluting our air, and contributing to global climate change.
Population growth. Today, over 6 billion people are living on Earth. Each
year we add about 80 million more. This growing population puts tremendous
pressure on the Earth s resources, hastening destruction of habitat, and increasing pollution.
Overconsumption. People in industrialized countries, such as the United
States, Japan, and France, together make up only one-quarter of the world s
population — and yet use three-quarters of its resources. We are using fossil
fuels, forests, fish, soil, water, and other resources faster than natural processes
can replenish them.
Reprinted with permission from Biodiversity Basics, ' 1999, a publication of World Wildlife Fund s
Windows on the Wild biodiversity education program. For more information please visit
www.worldwildlife.org/windows
page 10
* Adapted from WOW! A Biodiversity Primer, pages 30-31 and WOW! An Educator s Guide (World
Wildlife Fund, 1994)
Unit 3 Background: Why is Our Wildlife in Trouble?
Unit 3 Background: Introduction to Biodiversity
Why Conserve Biological Diversity?
Species extinction is a natural part of the evolutionary process. Due to
human activities, however, species and ecosystems are more threatened
today than ever before in recorded history. The losses are taking place
in tropical forests -- where 50 to 90 percent of identified species live -as well as in rivers and lakes, deserts and temperate forests, and on
mountains and islands. The most recent estimates predict that, at current
rates of deforestation, some two to eight percent of the Earth’s species
will disappear over the next 25 years. This represents the greatest loss of
biodiversity since the end of the Mesozoic era about 65 million years
ago.
While these extinctions are an environmental tragedy, they also have
profound implications for economic and social development. At least 40
percent of the world’s economy and 80 percent of the needs of the poor
are derived from biological resources. In addition, the richer the diversity of life, the greater the opportunity for medical discoveries, economic
development, and adaptive responses to such new challenges as climate
change. Furthermore, it is well known to ecologists that the more species
there are living in an ecosystem, the more stable the ecosystem is.
Increasing the number of species increases the productivity and the
ability to withstand, e.g., drought.
To date, an estimated 1.7 million species have been identified. The
exact number of the Earth’s existing species, however, is still unknown.
Estimates vary from a low of 5 million to a high of 100 million. Zoos and
botanical gardens are equipped to care for only a small fraction of the
species already known. As the majority of species are still unknown, it is
obvious that preserving a few species in a human made habitat is rather
futile. The only way to preserve the present biodiversity is by preserving
the species in their original habitats. It is crucial to establish a sufficient
number of large enough areas to sustain at least the more important
habitats.
The variety of life is our insurance policy. Our own lives and livelihood
depend on it.
Unit 3 Background: Biodiversity
page 11
Unit 3 Background: Introduction to Biodiversity
Notes
page 12
Unit 3 Background: Notes