Bio 345 Evolution FINAL EXAM SET
Questions and Answers
Biological Species Concept (BSC): - Correct Answers -Species are groups of actually or
potentially interbreeding natural populations that are reproductively isolated from other
such groups (Mayr, 1942)
If the species can mate and have fertile offspring
Phylogenetic Species Concept (PSC): - Correct Answers -A phylogenetic species is an
irreducible cluster of organisms diagnosably different from other such clusters, and
within which there is a parental pattern of ancestry and descent (Cracraft, 1989).
Introgression: - Correct Answers -Gene exchange across distantly related species
(Horizontal Gene Transfer)
derived character state - Correct Answers -newer, evolved character state
ancestral character - Correct Answers -a character that evolved in a common ancestor
of both groups
MRCA - Correct Answers -most recent common ancestor
Bootstrapping - Correct Answers -bootstrapping is used with parsimony. some of the
data is discarded and a phylogeny is generated. After doing that many times, if we
consistently get the same phylogeny, then we become confident that is the true
phylogeny, because multiple, somewhat different data sets yield the same answer.
Bootstrapping is often used to assess the degree of confidence in the individual
branches of a tree.
conservative characters - Correct Answers -Features that evolve slowly and are
retained with little or no change for long periods of evolutionary time.
Introgression: - Correct Answers -The movement, the incorporation, of genes from one
genetically distinct population (usually considered a species) into another.
Geographic isolation: - Correct Answers -Reduction or prevention of gene flow between
populations by an extrinsic barrier to movement, such as topographic features or
unfavorable habitat.
, Reproductive isolation: - Correct Answers -Reduction or prevention of gene flow
between populations by genetically determined differences between them.
Allopatric populations: - Correct Answers -Populations occupying separated geographic
areas.
Parapatric populations: - Correct Answers -Populations occupying adjacent geographic
areas, meeting at the border.
Sympatric populations - Correct Answers -Populations occupying the same geographic
area and capable of encountering each other.
Hybrid zone: - Correct Answers -A region where genetically distinct populations meet
and interbreed to some extent, resulting in some individuals of mixed ancestry (i.e.,
hybrids).
Sister species: - Correct Answers -two species descended from single ancestral species
Distinguished by chromosome rearrangements: inversions and reciprocal translocations
(especially) lead to reduced hybrid fertility
Premating barriers: - Correct Answers -Features that impede transfer of gametes to
members of other species
Postmating, prezygotic barriers: - Correct Answers -Mating or gamete transfer occurs,
but zygotes are not formed
Postzygotic barriers: - Correct Answers -Hybrid zygotes are formed but have reduces
fitness
Dobzhansky-Muller Incompatibility: - Correct Answers -hybrid sterility gradually evolves
over time due to incompatible interactions between genes
Haldane's Rule: - Correct Answers -one sex manifests sterility or inviability
Causes of Speciation: - Correct Answers -Ecological, Reproducitve isolation, Polyploidy,
Genetic Drift
Ecological: - Correct Answers -ecologically-based divergent selection produces barriers
to gene flow, reproductive isolation evolves as a byproduct of ecological adaptations to
a changing environment
Reproductive Isolation Reinforcement: - Correct Answers -selection against low fitness
hybrids drives selection for prezygotic isolation
Polyploidy: - Correct Answers -unreduced gametes, more common in plants
Questions and Answers
Biological Species Concept (BSC): - Correct Answers -Species are groups of actually or
potentially interbreeding natural populations that are reproductively isolated from other
such groups (Mayr, 1942)
If the species can mate and have fertile offspring
Phylogenetic Species Concept (PSC): - Correct Answers -A phylogenetic species is an
irreducible cluster of organisms diagnosably different from other such clusters, and
within which there is a parental pattern of ancestry and descent (Cracraft, 1989).
Introgression: - Correct Answers -Gene exchange across distantly related species
(Horizontal Gene Transfer)
derived character state - Correct Answers -newer, evolved character state
ancestral character - Correct Answers -a character that evolved in a common ancestor
of both groups
MRCA - Correct Answers -most recent common ancestor
Bootstrapping - Correct Answers -bootstrapping is used with parsimony. some of the
data is discarded and a phylogeny is generated. After doing that many times, if we
consistently get the same phylogeny, then we become confident that is the true
phylogeny, because multiple, somewhat different data sets yield the same answer.
Bootstrapping is often used to assess the degree of confidence in the individual
branches of a tree.
conservative characters - Correct Answers -Features that evolve slowly and are
retained with little or no change for long periods of evolutionary time.
Introgression: - Correct Answers -The movement, the incorporation, of genes from one
genetically distinct population (usually considered a species) into another.
Geographic isolation: - Correct Answers -Reduction or prevention of gene flow between
populations by an extrinsic barrier to movement, such as topographic features or
unfavorable habitat.
, Reproductive isolation: - Correct Answers -Reduction or prevention of gene flow
between populations by genetically determined differences between them.
Allopatric populations: - Correct Answers -Populations occupying separated geographic
areas.
Parapatric populations: - Correct Answers -Populations occupying adjacent geographic
areas, meeting at the border.
Sympatric populations - Correct Answers -Populations occupying the same geographic
area and capable of encountering each other.
Hybrid zone: - Correct Answers -A region where genetically distinct populations meet
and interbreed to some extent, resulting in some individuals of mixed ancestry (i.e.,
hybrids).
Sister species: - Correct Answers -two species descended from single ancestral species
Distinguished by chromosome rearrangements: inversions and reciprocal translocations
(especially) lead to reduced hybrid fertility
Premating barriers: - Correct Answers -Features that impede transfer of gametes to
members of other species
Postmating, prezygotic barriers: - Correct Answers -Mating or gamete transfer occurs,
but zygotes are not formed
Postzygotic barriers: - Correct Answers -Hybrid zygotes are formed but have reduces
fitness
Dobzhansky-Muller Incompatibility: - Correct Answers -hybrid sterility gradually evolves
over time due to incompatible interactions between genes
Haldane's Rule: - Correct Answers -one sex manifests sterility or inviability
Causes of Speciation: - Correct Answers -Ecological, Reproducitve isolation, Polyploidy,
Genetic Drift
Ecological: - Correct Answers -ecologically-based divergent selection produces barriers
to gene flow, reproductive isolation evolves as a byproduct of ecological adaptations to
a changing environment
Reproductive Isolation Reinforcement: - Correct Answers -selection against low fitness
hybrids drives selection for prezygotic isolation
Polyploidy: - Correct Answers -unreduced gametes, more common in plants
