Chapter
Objectives
- Explain what is meant
by the modern synthesis
- Explain how microevolutionary
change can affect a gene pool
- state the Hardy-Weinberg
theorem
- Write the general Hardy-Weinberg
equation and use it to calculate allele and genotype frequencies
- Explain the consequences
of Hardy-Weinberg equilibrium
- Demonstrate that a disequilibrium
population requires only one generation of random mating to
establish Hardy-Weinberg equilibrium
- Describe the usefulness
of the Hardy-Weinberg equilibrium model to population genetics
- List the conditions
a population must meet in order to maintain Hardy-Weinberg
equilibrium
- Explain how genetic
drift, gene flow, mutation, nonrandom mating, and natural
selection can cause microevolution
- Explain the role of
population size in genetic drift
- Distinguish between
the bottleneck effect and the founder effect
- Explain why mutation
has little quantitative effect on a large population
- Describe how inbreeding
and assortive mating affect a population's allele frequencies
and genotype frequencies
- List factors that produce
geographic variation among closely related populations
- Explain why even though
mutation can be a source of genetic variability, it contributes
a negligible amount to genetic variation in a population
- Explain how genetic
variation may be preserved in a natural population
- Describe the neutral
theory of molecular evolution and explain how changes in gene
frequency may be nonadaptive
- Explain what is meant
by selfish DNA
- Explain the concept
of relative fitness and its role in adaptive evolution
- Explain why the rate
of decline for a deleterious allele depends upon whether the
allele is dominant or recessive to the more successful allele
- Describe what selection
acts on and what factors contribute to the overall fitness
of a genotype
- Give examples of how
an organism's phenotype may be influenced by the environment
- Distinguish among stabilizing
selection, directional selection, and diversifying selection
- Define sexual dimorphism
and explain how it can influence evolutionary change
- Give at leas 4 reasons
why natural selection cannot breed perfect organisms
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- Distinguish between
anagenesis and cladogenesis
- Define morphospecies
and explain how this concept can be useful to biologists
- Define biological species
(E. Mayr)
- Describe some limitations
of the biological species concept
- Explain how gene flow
between closely related species can be prevented
- Distinguish between
prezygotic and postzygotic isolating mechanisms
- Describe 5 prezygotic
isolating mechanisms and give an example of each
- Explain why many hybrids
are sterile
- Explain how hybrid breakdown
maintains separate species even if gene flow occurs
- Distinguish between
allopatric and sympatric speciation
- Explain the allopatric
speciation model and describe the role of intraspecific variation
and geographical isolation
- Explain why peripheral
isolates are susceptible if geographic barriers arise
- Describe the adaptive
radiation model and use it to describe how it might be possible
to have many sympatric closely related species even if geographic
isolation is necessary for them to evolve
- Define sympatric speciation
and explain how polyploidy can cause reproductive isolation
- Distinguish between
autopolyploidy and allopolyploidy
- List some points of
agreement and disagreement between the 2 schools of thought
about the tempo of speciation (gradualism vs. punctuated equilibrium)
- Describes the origins
of evolutionary novelty
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Chapter
Terms:
Chapter
23 Terms |
population
genetics
modern synthesis
population
species
gene pool
genetic structure
Hardy-Weinberg theorem
Hardy-Weinberg equilibrium
Hardy-Weinberg equation
microevolution
bottleneck effect
|
founder
effect
gene flow
mutation
inbreeding
assortative mating
natural selection
polymorphism
geographical variation
cline
balanced polymorphism
heterozygote advantage
|
hybrid
vigor
frequency-dependent
selection
neutral variation
Darwinian fitness
relative fitness
stabilizing selection
directional selection
diversifying selection
sexual dimorphism
sexual selection |
Chapter
24 Terms |
macroevoluton
speciation
anagenesis
phyletic evolution
cladogenesis
branching evolution
species
prezygotic barriers
postzygotic barriers |
morphological
species concept
recognition species
concept
cohesion species concept
ecological species
concept
evolutionary species
concept
allopatric speciation
sympatric speciation
adaptive radiation
polyploidy |
autopolyploid
allopolyploid
hybrid zone
punctuated equilibrium
exaptation
paedomorphosis
allometric growth
heterochrony
homeosis |
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Chapter
Outline Framework
- Population Genetics
- The modern evolutionary
synthesis integrated Darwinian selection and Mendelian
inheritance
- The genetic structure
of a population is defined by its allele and genotype
frequencies
- The Hardy-Weinberg
theorem describes a nonevolving population
- Causes of Microevolution
- Microevolution is
a generation-to-generation change in a population's allele
or genotype frequencies
- The 5 causes of
microevolution are genetic drift, gene flow, mutation,
nonrandom mating, and natural selection
- Genetic Variation,
the Substrate for Natural Selection
- Genetic variation
occurs within and between populations
- Mutation and sexual
recombination generate genetic variation
- Diploidy and balanced
polymorphism preserve variation
- Natural selection
as the Mechanism of Adaptive Evolution
- Evolutionary fitness
is the relative contribution an individual makes to the
gene pool of the next generation
- The effect of selection
on a varying characteristic can be stabilizing, directional,
or diversifying
- Sexual selection
may lead to pronounced 2y differences between the sexes
- Natural selection
cannot fashion perfect organisms
- What is a Species?
- The biological species
concept emphasizes reproductive isolation
- Prezygotic and postzygotic
barriers isolate the gene pools of biological species
- The biological species
concept does not work in all situations
- Modes of Speciation
- Geographical isolation
can lead to the origin of species: allopatric speciation
- A new species can
originate in the geographical midst of the parent species:
sympatric speciation
- Genetic change in
populations can account for speciation
- The punctuated equilibrium
model has stimulated research on the tempo of speciation
- The Origin of Evolutionary
Novelty
- Most evolutionary
novelties are modified versions of older structures
- Genes that control
development play a major role in evolutionary novelty
- An evolutionary
trend does not mean that evolution is goal-oriented
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