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Chapter 10
Biodiversity
10.1 What Is Biodiversity?
10.2 Biodiversity at Risk
10.3 The Future of Biodiversity
10.1 Do now What do you see?
Compare the known amounts of species
types.
- Describe the diversity of species types on Earth,
relating the difference between known numbers and
estimated numbers.
- List and describe three levels of biodiversity.
- Explain four ways in which biodiversity is important to
ecosystems and humans.
- Analyze the potential value of a single species.
10.1 A. A World Rich in Biodiversity
• Biodiversity: “biological diversity” means the number of
different species in a given area
• Unknown Diversity
– We know about 1.7 million species, mostly insects
– We think there are 10 million more
• Known vs. Unknown
– Known: collected and described scientifically.
– Unknown: exist in the deep ocean, the rainforest etc..
10.1
A. A World Rich in Biodiversity
• Levels of
diversity- 3
levels
1. Species
diversity: the
number of
different
species in the
same area.
Carnivores
Herbivores
Plants
Decomposers
High diversity
Med. diversity
Low diversity
10.1 A. A World Rich in Biodiversity
• Levels of diversity – 3 levels
2. Ecosystem diversity – the variety of
habitats, communities and ecological
process in an ecosystem
Rainforest
Tundra
10.1
A. A World Rich in Biodiversity
• Levels of diversity – 3 levels
3. Genetic diversity – the different genes contained within
all members of a population
– A gene is a piece of DNA that codes for a trait
10.1 B. Species are connected to Ecosystems
• Biodiversity affects the
stability of a population.
• Each species is important
– dependent on or
depended upon by at least
one other species.
• When one species
disappears from an
ecosystem, a strand in a
food web is removed.
10.1 B. Species are connected to Ecosystems
• Keystone species:
• critical to the functioning of the
ecosystem in which it lives.
• it affects the survival of many other
species in its community. EX sea otter.
The loss of the sea otter populations
led to an unchecked sea urchin
population, which ate all the kelp
leading to the loss of kelp beds along
the U.S. Pacific Coast.
10.1 C. Species and Population Survival
• The level of genetic diversity within populations is a
critical factor in species survival.
• Genetic Variation increases the chances that some
members of the population may survive environmental
pressures or changes, It allows them to adapt to new
situations.
• Small and isolated populations are less likely to
survive if something changes.
Classwork
10.1 C. Species and Population Survival
• Bottleneck: when a population becomes
very small, so that only a few genetic
types survive.
• Fewer types means they will be less
likely to survive if something changes
• Even if the population increases again
its genetic diversity will be reduced,
thus more likely to inherit genetic
diseases.
• Example: what if I am a new predator in
this “population” and I can’t eat the
purple circles, but I easily eat all the
other types? What will happen to the
population?
10.1 D. Medical and Industrial Uses
• ¼ of the drugs in the US come
from plants
• ~100% of antibiotics come from
fungi
• Chemicals and industrial
materials often developed from
chemicals found in all kinds of
species
10.1 E. Agricultural Uses
• Most crop food around the world
comes from areas with high
biodiversity.
• Depending on few food sources
is dangerous. A plant disease can
wipe out whole food sources.
• Have you heard of the Irish
potato famine?
10.1 Agricultural Uses Irish Potato Famine
About two-fifths of the population was
solely reliant on this cheap crop for their
food. During the famine approximately 1
million people died and a million more
emigrated from Ireland, causing the island's
population to fall by between 20% and
25%.
The cause of the famine was a potato
disease commonly known as potato blight
which destroyed potato crops throughout
Europe during the 1840s.
Ethics, Aesthetics, and Recreation
10.1
Review questions
1. What is biodiversity?
2. How many species are known to man currently?
3. What is species diversity?
4. What is ecosystem diversity?
5. What is genetic diversity?
6. What is a keystone species?
Chapter 10
10.1 What Is Biodiversity?
10.2 Biodiversity at Risk
10.3 The Future of Biodiversity
• - Define and give examples of endangered and threatened species.
• - Describe several ways that species are being threatened with
extinction globally.
• - Explain which types of threats are having the largest impact on
biodiversity.
• - List areas of the world that have high levels of biodiversity and
many threats to species.
• - Compare the amount of biodiversity in the United States to that of
the rest of the world.
• Mass extinction :the extinction of many species in a relatively
short period of time .
- probably caused by a global change in climate.
-
10.2 A. Current Extinctions
• Between 1800-2100 ~25% of all
species will be extinct, scientists say
we are the cause. Ex
– Polar bears: global warming is
destroying their habitat
– Rhino: hunted for their horn
• Species that are at risk of extinction
are those that migrate, need large or
special habitats, and those that are
exploited by humans.
10.2 A. Current Extinctions
• Endangered species:
if not protected. Thus it is under
protection by regulations or conservation measures.
• Threatened species: has been identified to be likely to
become endangered, it has a declining population.
10.2 A. Current Extinctions
• We’ve been hunting animals to
extinction our whole existence.
10.2 B. Are humans the cause?
• Habitat destruction: human populations are increasing, this is
destroying habitats because they need more land to build
homes and to harvest resources.
• Fragmentation: species habitats are being broken up, this
makes it hard for some to live because they need big areas
• Exotic species: new to an area, not native
• Invasive exotic species: the environment has no natural
predators, so they take over and use all the resources
• Poaching: illegal hunting of a species
• Pesticides(kill bugs): destroy native plans; can also kill animals
10.2
C. Areas of critical biodiversity
• “endemic species”: is a species that is native to a
particular place and only found there.
• Tropical rain forests: cover ~7% of the earth, but they have
~1/2 of life.
• coral reefs: contain the majority of the ocean’s biodiversity,
~60% of them are threatened by people
• Biodiversity hotspots: 25 areas have been labeled as
“hotspots” because they are the most threatened
areas.Ex:
– Coastal areas
– Rainforests
- Islands
10.2
Review
1. What is an endangered species?
2. What is a threatened species?
3. What is poaching?
4. What is an endemic species?
5. What is a biodiversity hotspot?
6. What is habitat fragmentation?
7. What is a mass extinction?
Chapter 10
10.1 What Is Biodiversity?
10.2 Biodiversity at Risk
10.3 The Future of Biodiversity
• - List and describe four types of efforts to save individual
• species.
• - Explain the advantages of protecting entire ecosystems
• rather than individual species.
• - Describe the main provisions of the Endangered Species
• Act.
• - Discuss ways in which efforts to protect endangered
• species can lead to controversy.
• - Describe three examples of worldwide cooperative efforts
• to prevent extinctions
10.3 A. Saving species one at a time
• Captive breeding programs to restore the
population of a species
– Wildlife experts breed animals in captivity, then
release them into the wild. Ex: California condor
• In 1986 nearly extinct, birds were bred in captivity and
released, in 2005 there are 121 in the wild
• Preserving genetic material to save the
essence of a species
– “germ plasm” hereditary material (chromosomes
and genes) usually contained in the protoplasm of
germ cells and may be stored as seeds, sperm,
eggs, or pure DNA.
10.3 A. Saving species one at a time
• Zoos, aquariums
– Often house the few remaining
members of a species and keep them
safe.
– Have complex captive breeding
programs
• Parks, gardens (Botanical Gardens)
– House about 90,000 species of plants.
10.3 B. Preserving habitats and ecosystems
• Conservation strategies now focus on protecting
entire ecosystems to save most of the species in
an ecosystem instead of only the ones that have
been identified as endangered.
• Conservationists are focusing on hotspots
Ex: identify areas of native habitat that can be
preserved, restored, and linked into large
networks
• Most effective way to slow the loss of
biodiversity
10.3 C. Legal Protections for species
• US laws
– Strongest in the world
– Endangered species act was passed in 1973,
it was designed to protect plant and animal
species in danger of extinction.
• Reintroduced the gray wolf in the NW USA
• In 2005 1,272 species were listed as
endangered or threatened. You cannot:
–Capture endangered/threatened animals
for a zoo
–Dig up endangered plants
–Build a building over an endangered
species home
10.3 C. Legal Protections for species
• Recovery and habitat conservation plans
– Conservationists must make “species recovery plans” to set forth
a way to protect or restore the habitat of that species across large
areas of land through trade-offs or cooperative agreements.
– This is controversial, it sometimes hurts the income of business
and people.
10.3
D. International cooperation
• International trade and poaching
– CITES (Convention on International Trade in Endangered
Species.) first made to decrease ivory trade, it worked!
• The biodiversity treaty: more than 100 world leaders met at
“earth summit” to preserve biodiversity and ensure the
sustainable and fair use of genetic resources in all countries.
10.3 Review – Write Q & A
1.What is a captive breeding program?
2.What is the Endangered Species Act?
3.When was the Endangered Species Act
passed?
4.What is a habitat conservation plan?
5.What is CITES?
6.What is the Biodiversity Treaty?