Biodiversity at Risk

Essential Questions What factors influence changes in populations? How do species interact with one another?   - How has the human population changed over time? What is biodiversity? How do human population dynamics threaten biodiversity?

Mass Extinctions 5 during the past 500,000,000 years Dinosaurs 65mya Asteroid Volcanism Continental Drift Competition from Mammals

Some scientists say we are going through another mass extinction 25% of species extinct since 1800

Endangered Species Likely to become extinct if protective measures are not taken

Threatened Species Declining population and is likely to become endangered

Endangered Species Act 1973

International Union for Conservation of Nature Founded in 1948 1,100 member organizations 11,000 scientists

IUCN Red List 44,838 species assessed 868 species extinct or extinct in the wild 3,246 critically endangered 4,770 endangered 8,912 vulnerable

IUCN Red List 22% of mammals threatened 31% of amphibians threatened Indicator species 27% of coral reefs threatened

How do humans cause extinctions? Habitat Destruction Invasive Species Hunting Pollution