1. Biodiversity

2. Where are we?
Several mass extinctions have occurred in Earth’s history
Are we currently living during another mass extinction?

3. What is biodiversity?
Biodiversity- refers to the number and variety of species on Earth
Known species= 1.7 million
Estimates = over 10 million
Species are considered known when they are collected and scientifically described

4. Levels of biodiversity
Species diversity- # of different species in an area (also called biodiversity)
Ecosystem diversity- variety of habitats and ecological processes w/in an ecosystem
Genetic diversity-different genes contained w/in all members of a population
Gene- piece of DNA that codes for specific trait, that could be inherited by offspring

6. Value of biodiversity Preserving ecosystem balance
Keystone species- species that are critical to the functioning of an ecosystem
We depend on healthy ecosystem to ensure a healthy biosphere

7. Preserving ecosystem balance
Genetic diversity within populations are critical to species survival
Diversity comes from large populations
Bottleneck effect- population shrinks due to sudden event (natural disaster, human influence) leaving only a few members thus reducing genetic diversity

8. Value of biodiversity Practical uses of species Clothing Shelter
Medicine
¼ prescription drugs plants
Antibiotics  fungi
Food
Most new foods are hybrids- crops created by combining genetic information from various species

9. Value of biodiversity Aesthetic value or personal enjoyment Ethics
Ecotourism- business that supports the conservation and sustainable development of ecologically unique areas
Ethics
Belief of some that species and ecosystems have right to exist, regardless of their value

10. Biodiversity at risk Species at risk Species w/small populations
Migratory species
Those that need large tracts of land
Those exploited by humans

11. Endangered vs threatened
Endangered- likely to go extinct if protective measures are not taken immediately
Threatened- declining population and is likely to become endangered if it is not protected

12. How do humans cause extinctions?
Habitat Destruction & fragmentation
Invasive exotic species
Exotic species- species not native to a particular area
Poaching- illegally hunting, fishing, harvesting, or trading wildlife
Pollution

13. Areas of critical biodiversity
Endemic species- species that are native to and found only within a limited area
Tropical Rain Forest
Coral Reefs & Coastal Ecosystems
Islands

14. Biodiversity hotspots
Most threatened areas of high species diversity on Earth