Lecture 30: Threats to biodiversity Flashcards
How threats to biodiversity interact to increase extinction risk of species
Reduces potential for evolutionary adaptations
Natural selection is less effective in small populations
DDT effects on food chain (pollution)
Too much of insecticide in the environment results in bio-accumulation
Biomagnification effects on the food chain (pollution)
Pollution concentrations increase in organisms through the food chain
Apex predators suffer the most damage as they ingest the largest amounts of toxins
Difference between accidental and intentional introductions (non-native species)
Some species introduced deliberately to combat pests, while others accidentally introduced
5 Threats to biodiversity
Habitat Loss
Non-native species
Overharvesting
Pollution
Climate change
Groups of organisms most threatened by ocean acidification
Marine life
Mainly corals and oysters
Why small changes in temperature matter
Range expansion and contraction of organisms
Changes in life cycle like early flowering, mating, migration, due to warmer winter and springs
what is Bioaccumulation
Concentration of chemicals from the environment in an organism’s tissues
Two processes that contribute to sea level rise
Thermal expansion (water expands as temperature rises)
Melting of polar ice sheets
What is biomagnification
Accumulations of toxins through the trophic level of food chain
Mercury effects on the food chain (pollution)
Absorbed by autotrophs from the environment and accumulates in the tissues and organisms
What environmental factors increase likelihood new species will be successful in introduced location? (non-native species)
Mild climates
Abiotic factors
Changes that are included in climate change
Ocean acidificaiton
Increased temperature
Decrease in polar ice
Sea level rise
What population controls do non-native species escape in new range?
Biotic controls from predators and parasites
Bottleneck effect and overharvesting: What happens to genetic diversity?
Harvesting kills a large number of individuals and only a small subset of population is left
Change allele frequencies in population
