UNIT 2 — The Living World: Biodiversity

Types of Biodiversity

1. Genetic diversity = variation within species
   
   

2. Species diversity = number of species
   
   

3. Ecosystem diversity = variety of habitats
   
   

Higher biodiversity = more resilience

Ecosystem Services

• Provisioning: food, water, wood
  
  

• Regulating: climate regulation, flood control
  
  

• Supporting: nutrient cycling, soil formation
  
  

• Cultural: tourism, spiritual value
  
  

Island Biogeography

• Large islands = more species
  
  

• Islands closer to mainland = more species
  
  

• Isolation decreases biodiversity
  
  

• Applies to wildlife habitat fragments too
  
  

Adaptations & Evolution

• Natural selection favors traits that improve survival
  
  

• Environmental change → species adapt, migrate, or go extinct
  
  

Species Interactions

• Predation: one kills/eats another
  
  

• Parasitism: parasite benefits, host harmed
  
  

• Mutualism: both benefit
  
  

• Commensalism: one benefits, one unaffected
  
  

• Competition: organisms fight for resources
  
  

Threats to Biodiversity

• Habitat destruction (biggest cause)
  
  

• Invasive species
  
  

• Pollution
  
  

• Climate change
  
  

• Overharvesting
  
  

HIPPCO = main causes of extinction

• Habitat loss
  
  

• Invasive species
  
  

• Population growth
  
  

• Pollution
  
  

• Climate change
  
  

• Overharvesting