ASU BIO 182 EXAM 2 FINAL PAPER
FULL QUESTIONS AND CORRECT
SOLUTIONS +
⩥ What is mass extinction? Answer: A decline in biodiversity greater
than the background extinction rate
⩥ What is background extinction? Answer: Background extinction
occurs when certain populations are reduced to zero because of normal
environment change, emerging disease, predation pressure, or
competition with another species
⩥ How are mass extinctions detected and how many have been
detected? Answer: They're detected geologically, and there have been 5
detected
⩥ What organisms became extinct during the Pleistocene and
Cretaceous and what are possible causes for these extinctions? Answer:
Pleistocene: Wooly Mammoth, Giant Short-Faced Bear, Dire Wolf,
Giant Beaver, Shasta Ground Sloth, American Lion
-Could be extinct because of climate change (warmer temps), human
overkill (predation), pathogens
Cretaceous: Dinosaurs
-Could be extinct because of asteroid (impact hypothesis)
,⩥ What is the evidence to support that there will be a 6th mass
extinction? Answer: Modern rates of extinction are 100 to 1000 time
greater than the background rate
⩥ What is overexploitation? Answer: -Any unsustainable removal of
wildlife from the natural environment by use of humans
-Harvesting of organisms at rates exceeding the species ability to replace
itself
-The dominant threat to marine species
-Overhunting
⩥ What is habitat destruction? Answer: Terrestrial Ecosystems:
Conversion agriculture, logging, development and urbanization
Aquatic Ecosystems: Draining and developing wetlands, damming rivers
Species area curve - As the land area decreases, the number of species
decreases
⩥ What is habitat fragmentation? Answer: -The breakup of large pieces
of natural habitat into small, isolated pieces
-Can reduce a habitat to where it's too small to support a species
-Reduces the ability of individuals to disperse from one habitat to
another (could be more vulnerable to catastrophes)
, -Creates a large amount of "edge" habitat (Edge effects light levels,
pollution, poachers, and competition)
-The species most impacted by this are those that require large territories
to find food
⩥ How can an exotic species contribute to extinction? Answer: -An
introduction of a new species, that could possibly become an invasive
species
-An exotic species could carry pathogens
⩥ What are phenology shifts? Answer: *Related to global climate
change*
-Timing of seasonal events
-Concern mismatch between organisms
⩥ What are geographic range shifts? Answer: *Related to global climate
change*
-Organisms move into climates to which they're adapted
-Concern for organisms in arctic and alpine regions (running out of
habitat)
⩥ What are consequences of extinction? Answer: -Impacts productivity
and stability, and biological communities
-Ecosystem services
FULL QUESTIONS AND CORRECT
SOLUTIONS +
⩥ What is mass extinction? Answer: A decline in biodiversity greater
than the background extinction rate
⩥ What is background extinction? Answer: Background extinction
occurs when certain populations are reduced to zero because of normal
environment change, emerging disease, predation pressure, or
competition with another species
⩥ How are mass extinctions detected and how many have been
detected? Answer: They're detected geologically, and there have been 5
detected
⩥ What organisms became extinct during the Pleistocene and
Cretaceous and what are possible causes for these extinctions? Answer:
Pleistocene: Wooly Mammoth, Giant Short-Faced Bear, Dire Wolf,
Giant Beaver, Shasta Ground Sloth, American Lion
-Could be extinct because of climate change (warmer temps), human
overkill (predation), pathogens
Cretaceous: Dinosaurs
-Could be extinct because of asteroid (impact hypothesis)
,⩥ What is the evidence to support that there will be a 6th mass
extinction? Answer: Modern rates of extinction are 100 to 1000 time
greater than the background rate
⩥ What is overexploitation? Answer: -Any unsustainable removal of
wildlife from the natural environment by use of humans
-Harvesting of organisms at rates exceeding the species ability to replace
itself
-The dominant threat to marine species
-Overhunting
⩥ What is habitat destruction? Answer: Terrestrial Ecosystems:
Conversion agriculture, logging, development and urbanization
Aquatic Ecosystems: Draining and developing wetlands, damming rivers
Species area curve - As the land area decreases, the number of species
decreases
⩥ What is habitat fragmentation? Answer: -The breakup of large pieces
of natural habitat into small, isolated pieces
-Can reduce a habitat to where it's too small to support a species
-Reduces the ability of individuals to disperse from one habitat to
another (could be more vulnerable to catastrophes)
, -Creates a large amount of "edge" habitat (Edge effects light levels,
pollution, poachers, and competition)
-The species most impacted by this are those that require large territories
to find food
⩥ How can an exotic species contribute to extinction? Answer: -An
introduction of a new species, that could possibly become an invasive
species
-An exotic species could carry pathogens
⩥ What are phenology shifts? Answer: *Related to global climate
change*
-Timing of seasonal events
-Concern mismatch between organisms
⩥ What are geographic range shifts? Answer: *Related to global climate
change*
-Organisms move into climates to which they're adapted
-Concern for organisms in arctic and alpine regions (running out of
habitat)
⩥ What are consequences of extinction? Answer: -Impacts productivity
and stability, and biological communities
-Ecosystem services
