Biodiversity The degree of variation of life forms within a given ecosystem  Biome  Biosphere

Largest forms of life

Smallest forms of life

Species Diversity The number of species in a given area

Extinction The end of a species of an organism  No longer found on earth  800 plant and animal species in the past 500 yrs Extinct animals Labrador Duck (skunk duck)  1878: New York City  Over harvesting by humans (hunting)

Extinct Species Javan Tiger  Indonesian Islands  1976  Human expansion  Food source exhausted (Rusa deer) Bali Tiger  1937  Habitat loss  Over harvesting

Extinct species Tarpan (wild horse)  Poland and Russia  1909

Extinct Species North African Elephant Egypt and Mediterranean Used as war elephants

Extinct Species Passenger Pigeon 1914 North America

Extinct Species Dodo Bird Late 17 th century Island of Mauritius

Endangered Species Endangered list A species whose numbers are so small that it is at risk of extinction Arctic Fox Arctic tundra (Alaska, Canada, Russia)  Pop. 100’s of thousands  Climate change  Fur harvesting  Diseases from wild dogs

Endangered Species Peregrine Falcon 1650 breeding pairs U.S. and Canada: wide range  DDT and DDE (pesticides banned in the 1970’s) causes thinning of egg shells

Endangered Species Killer Whale Less than 50,000  Pollution and chemical contamination  Makes them more susceptible to disease

Endangered Species Monarch Butterfly North and Central America- migrate to Mexico  Harvesting lumber in the area  Climate – changes migration area  Loss of milkweed plants

Endangered Species American Alligator Southeastern U.S.- 5 million  Climate change  Loss of habitat  Hunted for their skin

Endangered Species American Bison (North America) 500,000  Disease - Crossbreeding with cattle  Hunting

Endangered Species African and Asian Elephants 450, ,000 African 35,000-40,000 Asian  Habitat loss  Tusk harvesting

Endangered Species California Condor 279 : 130 have been reintroduced into the wild Western U.S., Mexico, Canada  Lead poisoning  Electrocution on power lines  Poaching

Endangered Species Mountain Gorilla 700 Virunga mountain region (East Africa)  Habitat loss due to human population growth  Disease  Poaching

Endangered Species Woodland Caribou Alaska, Canada, British Columbia, Washington 2000  Habitat loss  Climate change

Endangered Species Black Rhino: 2,400 White Rhino: 7,500 Sumatran Rhino: 400 Javan Rhino: fewer than 100 Indian Rhino: more than 2,000  Poaching for horns

Endangered Species Ocelot North and South America 800,000 – 1.25 million  Habitat destruction  Fur harvesting 

Endangered Species Chimpanzee 100,000 – 200,000 African continent  Habitat destruction  Commercial exploitation

Endangered Species Giant Panda China 2000  Climate change affecting bamboo growth  Habitat loss due to farming

Endangered Species Koala Bear Australia Fewer than 100,000  Habitat destruction  Hunted for furs  Traffic accidents  Attacked by domestic dogs

Reasons Poaching Pollution Predation Over hunting Loss of habitat Disease Introduction of a new species Climate change Natural disasters  Hurricanes, volcanic eruptions etc.

Endemic Species A species that is geographically isolated  Native to the area

Endemic Species

Invasive Species A species that does not naturally occur in a specific area  Introduction causes harm to the rest of the ecosystem Zebra Mussels Dyer’s Woad Cheatgrass

Keystone Species A species that is vital to an ecosystem If it becomes extinct the entire ecosystem will be affected  Prevents other species from dominating an ecosystem  Maintain balance  Maintain biodiversity  Shape the land

Keystone Species

Mass Extinctions 99% of all species that have ever live are now extinct Mass Extinction: when several groups of species die out due to a major ecosystem changing event  Can affect land or sea life 1. Ordovician: 438 million years ago  Cause: Ice Age  100 families extinct  More than half of the bryozoan and brachiopod species extinct

Mass Extinctions 2. Devonian: about 370 mya  Cause: Global climate change: Ice Age or Warming Period  19% of animal families extinct (mostly Aquatic) 3. Permian: about 245 mya Largest mass extinction  Causes? Climate change due to mass volcanic eruptions or plate tectonic movement  90% of all species

Mass Extinctions 4. Triassic: 210 mya  Cause: Global Cooling: Ice Age or volcanic activity  28% of all animal families die out  Most early dinosaur families went extinct

Mass Extinctions 5. Cretaceous-Tertiary (K-T): 65 mya  Cause: meteor impact and/or volcanic eruptions  About half of all life forms died out including  Dinosaurs  Ammonites  Many families of fishes  Clams  Snails  Sponges  Sea urchins

The 6 th Extinction 1993: The Theory of the 6 th Extinction  Earth is losing an estimated 30,000 species per year Human causes Only extinction caused by biotic factors not abiotic factors  Pollution  Habitat destruction  Over harvesting  Exploitation of resources (poaching)  Introduction of invasive species