Biodiversity

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

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

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

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

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

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

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

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

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

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

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

Biodiversity hotspots Most threatened areas of high species diversity on Earth