JMU BIO 150 Exam 2 Questions And Answers With
Updates Solutions
/. Define macroevolution - Answer-evolutionary change above the species level,
including the origin of a new group of organisms or a shift in the broad pattern of
evolutionary changes over time
/.How do we identify a species? - Answer-groups of actually or potentially interbreeding
populations that are reproductivley isolated from other such groups
/.Define reproductive isolation - Answer-cannot produce viable offspring
/.Define viable - Answer-offspring can reproduce
/.Define speciation - Answer-splitting event that creates two or more distinct species
from a single ancestral group
/.What are the three stages of specification? - Answer-1. population separation
2. divergence
3. productive isolation preventing gene flow
/.Define population separation - Answer-isolation of gene pool
/.Define divergence - Answer-changes in gene pool (1 or both)
/.What are the two types of separation of populations? - Answer--allopatric model
-sympatric model
/.Define allopatric model - Answer-separation due to geographic isolation
/.Define sympatric model - Answer-separation due to competition or polylodisism in
population
/.What are the mechanisms of allopatric separation? - Answer--dispersal and
colonization
-vicariance
/.Define dispersal and colonization - Answer--start with one continuous population
-goes to an isolated area (island)
-finishes with one population isolated from the other
/.Define vicariance - Answer--start with one continuous population
-landscape is changed
-two populations are isolated from one another
, /.When does peripatric speciation occur? - Answer-when one of the isolated populations
have very few individuals
/.What causes divergence of populations in sympatric speciation? - Answer--disruptive
selection
-polyplodism
/.Define adaptive radiation - Answer-the rapid diversification of a group of organisms
into forms filling different ecological niches via sympatry
/.Define niches - Answer-role you fill in given environment
/.What drives adaptive radiation? - Answer--opportunity
-morphological innovations
-sex
/.How would you know if two species are productively isolated? - Answer--
unsuccessfully interbreed
-produce viable hybrids that are selected against
/.What are the types of prezygotic barriers? - Answer--habit isolation
-temporal isolation
-behavioral isolation
-mechanical isolation
-gametic isolation
/.Define habit isolation - Answer-different species breed in different habitats
/.Define temporal isolation - Answer-different species breed at different times
/.Define behavioral isolation - Answer-unique behavioral patters and rituals isolate
species
/.Define mechanical isolation - Answer-anatomical incompatibility preventing mating or
pollen transfer
/.Define gametic isolation - Answer-sperm and ova are chemically incompatible and will
not fuse to form a zygote
/.What are the postzygotic barriers? - Answer--reduced hybrid viability
-hybrid sterility
/.Define reduced hybrid viability - Answer-development of the zygote proceeds
abnormally and the hybrid is absorbed
Updates Solutions
/. Define macroevolution - Answer-evolutionary change above the species level,
including the origin of a new group of organisms or a shift in the broad pattern of
evolutionary changes over time
/.How do we identify a species? - Answer-groups of actually or potentially interbreeding
populations that are reproductivley isolated from other such groups
/.Define reproductive isolation - Answer-cannot produce viable offspring
/.Define viable - Answer-offspring can reproduce
/.Define speciation - Answer-splitting event that creates two or more distinct species
from a single ancestral group
/.What are the three stages of specification? - Answer-1. population separation
2. divergence
3. productive isolation preventing gene flow
/.Define population separation - Answer-isolation of gene pool
/.Define divergence - Answer-changes in gene pool (1 or both)
/.What are the two types of separation of populations? - Answer--allopatric model
-sympatric model
/.Define allopatric model - Answer-separation due to geographic isolation
/.Define sympatric model - Answer-separation due to competition or polylodisism in
population
/.What are the mechanisms of allopatric separation? - Answer--dispersal and
colonization
-vicariance
/.Define dispersal and colonization - Answer--start with one continuous population
-goes to an isolated area (island)
-finishes with one population isolated from the other
/.Define vicariance - Answer--start with one continuous population
-landscape is changed
-two populations are isolated from one another
, /.When does peripatric speciation occur? - Answer-when one of the isolated populations
have very few individuals
/.What causes divergence of populations in sympatric speciation? - Answer--disruptive
selection
-polyplodism
/.Define adaptive radiation - Answer-the rapid diversification of a group of organisms
into forms filling different ecological niches via sympatry
/.Define niches - Answer-role you fill in given environment
/.What drives adaptive radiation? - Answer--opportunity
-morphological innovations
-sex
/.How would you know if two species are productively isolated? - Answer--
unsuccessfully interbreed
-produce viable hybrids that are selected against
/.What are the types of prezygotic barriers? - Answer--habit isolation
-temporal isolation
-behavioral isolation
-mechanical isolation
-gametic isolation
/.Define habit isolation - Answer-different species breed in different habitats
/.Define temporal isolation - Answer-different species breed at different times
/.Define behavioral isolation - Answer-unique behavioral patters and rituals isolate
species
/.Define mechanical isolation - Answer-anatomical incompatibility preventing mating or
pollen transfer
/.Define gametic isolation - Answer-sperm and ova are chemically incompatible and will
not fuse to form a zygote
/.What are the postzygotic barriers? - Answer--reduced hybrid viability
-hybrid sterility
/.Define reduced hybrid viability - Answer-development of the zygote proceeds
abnormally and the hybrid is absorbed
