Ch. 10 Biodiversity
Sect. 1 Objectives
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.
Biodiversity (biological diversity) – ______
Ex: Plants, Animals, Mammals, insects, fish, crustaceans, Fungus, Insects, Bacteria, Etc.
How many Species are there?
1.7 million species are known - ______
______species are estimated to exist
Levels of Diversity
Species diversity – ______
Ecosystem diversity – variety of habitats, communities
Genetic diversity – number of genes contained in ______
What makes everything different?
Genes (DNA) – code for different traits or ______
Everyone's is different (unless you are an identical twin)
Why is Biodiversity Important?
All species are dependant on other species and are depended on by others
Everyone fits in the food web/chain
If you remove one link, all the others will fall
Keystone species – ______because it affects the survival and abundance of many other species
– ______
Ex: Sea Otters
1. Otters killed for fur, 2. Sea urchin population grew, 3. Kelp disappeared
Biodiversity and Survival
______means the population has a greater chance of ______. (ie: global warming)
Biodiversity and Humans
More organisms the more things for us: Food, Antibiotics, Clothing, Shelter, Chemicals
Ecotourism – ______of ecologically unique areas
Sect. 2 Objectives
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.
Extant – ______
Threatened – ______but is likely to become endangered because of their declining numbers
Endangered – so few individuals that they are ______
Extinct – ______
Species most at risk
Animals that are more likely to become extinct are those that:
Have small populations
______
Need large or special habitats
______
Currently humans are the greatest cause of extinctions!
Species can be threatened by
-Humans
Hunting
______(75% of current extinctions)
Deforestation, Damming, Burning, Growing cities, Pollution
Poaching
______
-Natural Causes
Interbreeding, Natural Disaster, Disease
Exotic – ______
When brought to a new area exotic species can cause the extinction of other species they out compete Ex: Fire Ant: Horny Toads (Desert Horned Lizard) eat ants, but Fire ants (exotic species) kill horny toads. Horny toads are now threatened!
Generalist Species - Species with a broad niche, ______
Specialist Species - Species with a narrow niche. Ex: Koala
Critical Areas
-Tropical Rain Forests – ______
Most species have not been named, yet. But, lots of these are disappearing due to ______!
-Coral Reefs and Coastal areas
-Islands – why?
Biodiversity Hotspots – ______
Endemic Species – ______
Madagascar
Endemic Species: 80% of plants , 91% of reptiles, 100% of lemurs (10% of worlds primate population)