Chapter 10: Biodiversity
Jan 18, 2016
Chapter 10: Biodiversity
Chapter 10 Biodiversity Big Ideas
The huge diversity of life on Earth is critical to all species.
Some factors about species make them prone to extinction.
Human activities are causing large numbers of species to go extinct.
Section 1: What is biodiversity?
How many species live on Earth? Describe the types of biodiversity. Explain the importance of biodiversity. Terms: biodiversity, gene, keystone
species, ecotourism
Biodiversity Biodiversity: the
number of different species in a given area
Tropical rain forests
What factors lead to biodiversity?
• About 1.7 million species are known
• Estimated to be greater than 10 million
•Why so many unknown?
Biodiversity
Which species rule the world?
Levels of BiodiversitySpecies Biodiversity: differences between
populations number of different
species in an area
Ecosystem Diversity: how many types of
habitats or communities in an area
Genetic Diversity: number of genes in all members of a population
What is a gene?
Gene: a piece of DNA code for a specific trait inherited
Tall, short, brown eyes, etc.
Genetic Diversity among corn
Levels of Biodiversity
Genetic diversity: Differences in DNA among individuals
Species diversity: Variety of species in a given area
Ecosystem diversity: Variety of habitats, ecosystems, communities
Ecosystem diversity often leads to species diversity and often leads to genetic diversity
Did You Know?In general, biodiversity increases toward the equator.
Who cares about Biodiversity?A Variety of Answers
We Care !
Benefits of Biodiversity Genetic Diversity
Key To Survival Small isolated
populations unlikely to survive• Genetic mutations
from inbreeding can occur
More diversity = more likely to survive
Why is genetic diversity important?
Cavendish banana
“ The fungus Fusarium oxysporum wiped out the previous species of bananas (the Gros Michel) in the 1950s. Now it’s back, having evolved to be able to take on the previously resistant “back-up” species of banana — the Cavendish — that replaced the superior Gros Michel banana after it was wiped out. “
Benefits of Biodiversity: Ecosystem Services
Intact environments provide ecosystem services• water purification and pest control
High biodiversity increases stability of communities and ecosystems• enables them to perform services.
Stable ecosystems are resistant and resilient
Benefits of Biodiversity
Keystone Species: species that is critical to ecosystem survival• Sea Otter• Grey Wolf• Beaver
Keystone Species
Food Web Depends Upon Krill
Benefits of Biodiversity Species
Population and Survival:• Genetic diversity
increases chance that some survive environmental pressures or changes
Benefits of Biodiversity
Medical, Industrial, Agricultural Uses
Food, cloths, shelter, chemicals and medicine often comes from variety of organismsSee Table 1 page 243
Medical
Medicine: Organisms contain compounds that are useful for treating disease Did You Know?
Of the 150 most prescribed drugs in the United States, 118 originated in nature.
The yew tree, an original source of Taxol, a cancer-fighting drug
Agricultural
Humans benefit every time we eat
Most foods come from areas of high biodiversity
Benefits of Biodiversity
Ethics, Aesthetics and Recreation
Moral, religious purposes for all species
Personal enjoyment
Dolphin Tour Off NJ Beaches
Benefits of Biodiversity
Ecotourism: tourisms that supports conservation
Wildlife, birding, wilderness hiking
People make money by having people view wildlife
Section 1 Review
How many species live on Earth? Describe the types of biodiversity. Explain why biodiversity is important.
Section 2: Biodiversity at Risk
What does it mean when a species is threatened or endangered?
What makes some species more prone to extinction?
What are the largest threats to biodiversity? Which areas are likely to have high
biodiversity?
Biodiversity has increased over time, but mass extinctions are also natural events (5 major events)
How do we get this data?
Extinctions Species gone forever NORMAL Mass Extinction: short
period of time when large number of species go extinct (65 MYA)
Currently in a mass extinction…caused by humans
Rapid climate change
• There have been five mass extinctions in Earth’s history.
• Each time, more than 1/5 of all families and 1/2 of all species have gone extinct.
Biodiversity at RiskCurrent extinction rate 100 to 1000 times greater than the natural background rate
In 2009, 1321 species in the U.S. were classified as endangered or threatened.
Endangered: At serious risk of extinction
Threatened: Likely to become endangered soon through all or part of its range
ExtinctionsCertain traits make
some species more vulnerable:
Small populations Specialized
• Niche• Habitat
Need large range Migrate Valuable to humans
Species squeezed into smaller and smaller fragmented habitat
Current Extinctions
Endangered Species: is likely to go extinct if actions not taken
Threatened: population declining and likely to become endangered
Current Extinctions
TNC estimates 1/3rd of 21,000 identified U.S. animal and plant species are vulnerable.
30,000 of the world’s species and 1,200 in U.S. are officially endangered.
Types of endangered species worldwide
How do humans cause extinctions?
“HIPPO”Habitat
destruction Invasive
speciesPopulation
(humans) growth
PollutionOverharvesting
Habitat Loss/Fragmentation
Habitat Fragmentation
Habitat fragmentation: Patches of suitable habitat surrounded by unsuitable habitat
In general, larger habitat fragments can support greater biodiversity than smaller fragments
Humans Causing Extinctions
Habitat Destruction causes 75-80%
Large creatures need a lot of land
Invasive Species: exotic species not native to area can destroy an ecosystem
Invasive Species
Invasive species can out-compete and displace native species
Invasive Species
CA Agricultural Checkpoints
Humans Causing Extinction Over-harvesting
excessive hunting• (bison in U.S., fish,
passenger pigeon) Poaching: illegal
hunting• Common in poor
countries for food, medicines, income
Pollution air, water, land• DDT, drugs, chemicals
Causes of Extinction Climate Change
Increasingly becoming a factor in biodiversity loss
Unlike the other factors, climate change has a potential global effect on biodiversity
Areas of Critical Biodiversity
Tropical Rain Forests
Coral Reefs Coastal
Ecosystems IslandsWhy these
areas????
Just 2.3% of the planet’s land surface is home to 50% of the world’s plant species and 42% of its vertebrate animal species.
Areas of Critical Biodiversity
Hotspots: most threatened areas of high biodiversity
Roughly 25 worldwide
Madagascar Parts of California Caribbean
Hotspots
Large numbers of endemic species: species native to that area
US Hotspots
California Floristic Province – • 3488 native plants / 2124 endemic / 565 threatened or endangered• agriculture, housing, dams, overuse of water, destructive recreation,
mining
Section 2 Review
What does it mean when a species is threatened or endangered?
What makes some species more prone to extinction?
What are the largest threats to biodiversity? What areas are likely to have high
biodiversity?
Section 3: Future of Biodiversity
List and describe efforts to save individual species
Explain the advantages of protecting entire ecosystems rather than individual species
Describe the main parts of the Endangered Species Act
Saving Individual SpeciesCaptive Breeding
Programs: breeding species in captivity with hopes of reintroducing into native habitats
Germ Plasm: saving genetic material for possible future use(seeds ,sperm, eggs, DNA)
Zoos &Aquariums, Wildlife Parks & Gardens
Saving Individual Species
Does little to preserve species
Captive individuals may not survive in wild
Small populations have difficult time with inbreeding, diseases
Last resorts
Preserving Habitat and Ecosystems Most effective way
to save a species is protect its habitat
Some species require large areas
What about when they leave protected areas? (Wolves in Yellowstone
Best way to protect individual species is to protect all species in the ecosystem
Legal Protections
Many countries have laws to protect wildlife
Some weak Some strong U.S. law
Endangered Species Act (ESA) one of the strongest
ESAEndangered Species
Act Passed 1973 Protect plant and
animals in danger of extinction
List created of those threatened and endangered
Currently ~1400 listed
2000 total worldwide
ESA• Forbids governments and citizens from harming listed species and habitats
• Forbids trade in products made from listed species
ESA Protects listed
species from harm No development
that harms listed species
What does that all mean?
Can a Shopping Mall be built where listed species lives?
Spotted Owl
ESA Species recovery plan
must be made Habitat Conservation
Plans: plans to protect or restore species habitat
Why do you think ESA may be controversial?
Who would not like this law?
ESAESA: 1973-2010: 92 to
~1400 species listed 54 Species removed
(26 recovery, 10 extinctions, 18 errors, rest discovered more)
60% plants, 40% animals
TNC says 1/3rd of all U.S. species…30,000 not 1,260
NJ ESA Listhttp://www.state.nj.us/dep/fgw/tandespp.htm
Wildlife Corridors Connect habitat
fragments enabling once-isolated populations to interbreed
Interbreeding increases genetic diversity
Yellowstone to Yukon
Internationally International Union for the
Conservation of Nature & Natural Resources (IUCN)• Red List of worldwide
endangered species• CITES Treaty 1989
(Convention on International Trade of Endangered Species)
• Illegal to trade endangered species
Ivory Tusks
Internationally Much more difficult
among may poorer countries
International treaties hard to ratify, verify• The Biodiversity Treaty
Oceans of particular concern
Private conservation efforts often more effective (WWF,TNC,CI)
• http://animal.discovery.com/tv/whale-wars/
Section 3 Review
List and describe efforts to save individual species.
Explain the advantages of protecting entire ecosystems rather than individual species.
Describe the main parts of the Endangered Species Act.
Terms: Endangered Species Act, habitat conservation plans, CITES
Chapter 10 Biodiversity Review
There is a huge diversity of life on Earth that is critical to all species. .
There are some factors about species that make them prone to extinction.
Human activities are causing large numbers of species to go extinct.