PCB 3044
PCB 3044 Exam 4 |Questions with
Correct Answers |Updated 2026
What is biogeography?
Study of patterns of variation in species composition and diversity among
geographic locations
Which biome has the most biodiversity?
Forest biomes (tropical rainforests)
How is tree species diversity affected by latitude?
Tree species diversity decreases with increasing latitude
What are endemic species?
Species found only in one place on Earth
The same community type or biome, varies in species richness and composition
depending on its _______________ on Earth
location
Species richness and composition are not the same in every
___________________
continent
Spatial scales are interconnected in a _________________ way
hierarchical
The patterns of species diversity and composition at one spatial scale set the
conditions for patterns at _____________ spatial scales.
smaller
What are the 4 spatial scales?
Global, regional, landscape, and local scales
Differentiate the 4 spatial scales
PCB 3044
,PCB 3044
- Global scale: The entire world
- Regional scale: Within areas of uniform climate
- Landscape scale: Physical geography and environmental features of a region
Local scale: A community
What is a regional species pool?
All the species contained within a region (gamma diversity)
How are differences in species diversity determined at the global scale?
Rates of speciation, extinction, and dispersal
How are differences in species diversity determined at the regional scale?
Extinction and dispersal limitation
How are differences in species diversity determined at the landscape scale?
Migration and extinction rates (shaped by landscape features)
How are differences in species diversity determined at the local scale?
Species physiology and species interactions
Differentiate alpha, beta, and gamma diversity
- Alpha: Within community diversity
- Beta: Between community diversity
- Gamma: Total diversity (regional species pool)
Beta diversity connects species diversity between which two spatial scales?
Local and regional scales
What is beta diversity?
Change in species number and composition (turnover) from one community
type to another, across a landscape
_____________ diversity sets the theoretical upper limit on species diversity for
communities
Gamma
The regional species pool (i.e. gamma diversity) provides raw material for
___________ assemblages
PCB 3044
,PCB 3044
local
When local and regional species richness values are equal (slope = 1), what does
that signify?
All species within a region will be found in the communities of that region
When local species richness values increase with regional values proportionally
(slope < 1), what does that signify?
Community richness is mostly determined by the regional species pool (gamma
diversity)
If local richness stays the same as regional richness increases (curve levels off),
what does this signify?
Local processes are limiting local species diversity
Who is the father of biogeography?
Alfred Russel Wallace (1823-1913)
What did Wallace co-discover with Darwin?
Natural selection
Wallace noticed mammals of the Philippines were more similar to those in
_____________ (5,500 km away) than they were to those in _________________
(750 km away)
Africa ; New Guinea
What is Wallace's line?
A line separating Australian faunal species from Asian species
What are two global patterns Wallace revealed?
- Land masses can be divided into 6 biogeographic regions
- There's a gradient of species diversity with latitude (i.e. species diversity is
highest in the tropics and decreases towards the poles)
Name the 6 biogeographic regions
Neartic, neotrophical, paleartic, ethiopian, oriental, australasian
What two things are the 6 biogeographic regions based on?
PCB 3044
, PCB 3044
- Earth's major tectonic plates
- Terrestrial animals
What are tectonic plates?
Section's of Earth's crust that are broken and move around
What causes tectonic plates to move (continental drift)?
Convection currents in the molten rock mantle
What is Pangaea and when did it exist?
- A large continent containing all land masses
- Existed 251 million years ago (early Triassic)
Pangaea split into ____________ (north) and _____________ (south) about
______ million years ago, during the mid-Cretaceous period
Laurasia ; Gondwana ; 100
Laurasia and Gondwana broke up into today's continents about ____ million
years ago
60
North and South America were joined by the Isthmus of ______________ about
___ million years ago
Panama ; 6
What is vicariance?
- Geographical separation of a population
- Usually by a physical barrier such as mountain ranges, rivers, or continental
drift
Biodiversity hot spots also occur at particular ____________________
longitudes
Do all groups show a decrease in species richness at high latitudes?
No
Richness and productivity of marine benthic communities increases at
___________ latitudes
PCB 3044
PCB 3044 Exam 4 |Questions with
Correct Answers |Updated 2026
What is biogeography?
Study of patterns of variation in species composition and diversity among
geographic locations
Which biome has the most biodiversity?
Forest biomes (tropical rainforests)
How is tree species diversity affected by latitude?
Tree species diversity decreases with increasing latitude
What are endemic species?
Species found only in one place on Earth
The same community type or biome, varies in species richness and composition
depending on its _______________ on Earth
location
Species richness and composition are not the same in every
___________________
continent
Spatial scales are interconnected in a _________________ way
hierarchical
The patterns of species diversity and composition at one spatial scale set the
conditions for patterns at _____________ spatial scales.
smaller
What are the 4 spatial scales?
Global, regional, landscape, and local scales
Differentiate the 4 spatial scales
PCB 3044
,PCB 3044
- Global scale: The entire world
- Regional scale: Within areas of uniform climate
- Landscape scale: Physical geography and environmental features of a region
Local scale: A community
What is a regional species pool?
All the species contained within a region (gamma diversity)
How are differences in species diversity determined at the global scale?
Rates of speciation, extinction, and dispersal
How are differences in species diversity determined at the regional scale?
Extinction and dispersal limitation
How are differences in species diversity determined at the landscape scale?
Migration and extinction rates (shaped by landscape features)
How are differences in species diversity determined at the local scale?
Species physiology and species interactions
Differentiate alpha, beta, and gamma diversity
- Alpha: Within community diversity
- Beta: Between community diversity
- Gamma: Total diversity (regional species pool)
Beta diversity connects species diversity between which two spatial scales?
Local and regional scales
What is beta diversity?
Change in species number and composition (turnover) from one community
type to another, across a landscape
_____________ diversity sets the theoretical upper limit on species diversity for
communities
Gamma
The regional species pool (i.e. gamma diversity) provides raw material for
___________ assemblages
PCB 3044
,PCB 3044
local
When local and regional species richness values are equal (slope = 1), what does
that signify?
All species within a region will be found in the communities of that region
When local species richness values increase with regional values proportionally
(slope < 1), what does that signify?
Community richness is mostly determined by the regional species pool (gamma
diversity)
If local richness stays the same as regional richness increases (curve levels off),
what does this signify?
Local processes are limiting local species diversity
Who is the father of biogeography?
Alfred Russel Wallace (1823-1913)
What did Wallace co-discover with Darwin?
Natural selection
Wallace noticed mammals of the Philippines were more similar to those in
_____________ (5,500 km away) than they were to those in _________________
(750 km away)
Africa ; New Guinea
What is Wallace's line?
A line separating Australian faunal species from Asian species
What are two global patterns Wallace revealed?
- Land masses can be divided into 6 biogeographic regions
- There's a gradient of species diversity with latitude (i.e. species diversity is
highest in the tropics and decreases towards the poles)
Name the 6 biogeographic regions
Neartic, neotrophical, paleartic, ethiopian, oriental, australasian
What two things are the 6 biogeographic regions based on?
PCB 3044
, PCB 3044
- Earth's major tectonic plates
- Terrestrial animals
What are tectonic plates?
Section's of Earth's crust that are broken and move around
What causes tectonic plates to move (continental drift)?
Convection currents in the molten rock mantle
What is Pangaea and when did it exist?
- A large continent containing all land masses
- Existed 251 million years ago (early Triassic)
Pangaea split into ____________ (north) and _____________ (south) about
______ million years ago, during the mid-Cretaceous period
Laurasia ; Gondwana ; 100
Laurasia and Gondwana broke up into today's continents about ____ million
years ago
60
North and South America were joined by the Isthmus of ______________ about
___ million years ago
Panama ; 6
What is vicariance?
- Geographical separation of a population
- Usually by a physical barrier such as mountain ranges, rivers, or continental
drift
Biodiversity hot spots also occur at particular ____________________
longitudes
Do all groups show a decrease in species richness at high latitudes?
No
Richness and productivity of marine benthic communities increases at
___________ latitudes
PCB 3044
