BIO 206 FINAL EXAM QUESTIONS AND CORRECT
DETAILED ANSWERS (VERIFIED ANSWERS) |ALREADY
GRADED A+||BRAND NEW
Homoplasy Ans✓✓✓A similar (analogous) structure or molecular
sequence that has evolved independently in two species.
Problems with Homoplasy Ans✓✓✓It can create an unpredictable gain
or loss of a specific trait over time and during the evolution of new
species
Slowly evolving genes Ans✓✓✓Useful for distantly related species
Rapidly evolving species Ans✓✓✓useful for closely related species
Most useful traits Ans✓✓✓Shared derived traits
convergent evolution Ans✓✓✓repeated evolution of a trait
Homology Ans✓✓✓Similarity in characteristics resulting from a shared
ancestry.
Synapomorphies Ans✓✓✓shared derived characteristics that evolved in
a common ancestor of the group and were inherited by all of its
descendants
,Evolution Ans✓✓✓change in allele frequencies through time
Population genetics Ans✓✓✓- tracks the fate, across generations, of
alleles in populations
- concerned with whether a particular allele or genotype will become
more or less common over time, and WHY
single locus polymorphism Ans✓✓✓genes that control a single trait
additive ("incomplete dominance") Ans✓✓✓allele yields twice the
phenotypic effect when 2 copies are present (phenotype is in-between)
5 Hardy Weinberg Assumptions Ans✓✓✓1. No selection
2. No mutation
3. No migration
4. No chance events
5. There is random mating
Primary uses of HWE Ans✓✓✓- compute genotype frequencies from
generation to generation
- null model in tests for evolution (compares observed to expected)
- forensic analysis
,Common mistake of HWE Ans✓✓✓- Population is in HWE because it
sums to 1, this is just to check your math
* To determine HWE you need to COMPARE observed to expected *
Genetic Drift Ans✓✓✓- A change in the allele frequency of a
population as a result of chance events rather than natural selection
- Alleles are "sampled" to form progeny
Finite Population Ans✓✓✓- Chance events
- Randomly pair egg and sperm to make zygotes. If population is finite
in size, WILL NOT GET allele frequencies in their exact proportions
Genetic Bottleneck Ans✓✓✓Non-representative set of alleles for
subsequent populations, even after the population size rebounds
Founder Effect Ans✓✓✓- Type of genetic bottleneck resulting from a
small number of individuals colonizing a new, isolated habitat
- Not representative of source population
Properties of genetic drift Ans✓✓✓- DIRECTION of change in allele
frequency can NOT be PREDICTED
- One allele will eventually be fixed, the other eliminated: genetic drift
tends to REMOVE VARIATION
- Probability that a particular allele will eventually be fixed (or lost) is
proportional to its frequency in the population
, What does drift do to genetic diversity? (One word) Ans✓✓✓Reduces
3 main features of genetic drift Ans✓✓✓- loss of genetic variation
results WITHIN populations (1 allele will eventually be lost or fixed)
- Genetic divergence results BETWEEN populations (populations
become more different by chance)
- Drift CAUSES evolution, but NOT adaptive evolution
Fitness Ans✓✓✓expected reproductive success of an individual with a
particular phenotype (or genotype)
3 components of fitness Ans✓✓✓- survival to reproductive age
- mating success
- fecundity
Absolute fitness equation Ans✓✓✓(probability of survival) * (average
number of offspring)
Relative Fitness Ans✓✓✓Fitness of a genotype standardized by
comparison to other genotypes
DETAILED ANSWERS (VERIFIED ANSWERS) |ALREADY
GRADED A+||BRAND NEW
Homoplasy Ans✓✓✓A similar (analogous) structure or molecular
sequence that has evolved independently in two species.
Problems with Homoplasy Ans✓✓✓It can create an unpredictable gain
or loss of a specific trait over time and during the evolution of new
species
Slowly evolving genes Ans✓✓✓Useful for distantly related species
Rapidly evolving species Ans✓✓✓useful for closely related species
Most useful traits Ans✓✓✓Shared derived traits
convergent evolution Ans✓✓✓repeated evolution of a trait
Homology Ans✓✓✓Similarity in characteristics resulting from a shared
ancestry.
Synapomorphies Ans✓✓✓shared derived characteristics that evolved in
a common ancestor of the group and were inherited by all of its
descendants
,Evolution Ans✓✓✓change in allele frequencies through time
Population genetics Ans✓✓✓- tracks the fate, across generations, of
alleles in populations
- concerned with whether a particular allele or genotype will become
more or less common over time, and WHY
single locus polymorphism Ans✓✓✓genes that control a single trait
additive ("incomplete dominance") Ans✓✓✓allele yields twice the
phenotypic effect when 2 copies are present (phenotype is in-between)
5 Hardy Weinberg Assumptions Ans✓✓✓1. No selection
2. No mutation
3. No migration
4. No chance events
5. There is random mating
Primary uses of HWE Ans✓✓✓- compute genotype frequencies from
generation to generation
- null model in tests for evolution (compares observed to expected)
- forensic analysis
,Common mistake of HWE Ans✓✓✓- Population is in HWE because it
sums to 1, this is just to check your math
* To determine HWE you need to COMPARE observed to expected *
Genetic Drift Ans✓✓✓- A change in the allele frequency of a
population as a result of chance events rather than natural selection
- Alleles are "sampled" to form progeny
Finite Population Ans✓✓✓- Chance events
- Randomly pair egg and sperm to make zygotes. If population is finite
in size, WILL NOT GET allele frequencies in their exact proportions
Genetic Bottleneck Ans✓✓✓Non-representative set of alleles for
subsequent populations, even after the population size rebounds
Founder Effect Ans✓✓✓- Type of genetic bottleneck resulting from a
small number of individuals colonizing a new, isolated habitat
- Not representative of source population
Properties of genetic drift Ans✓✓✓- DIRECTION of change in allele
frequency can NOT be PREDICTED
- One allele will eventually be fixed, the other eliminated: genetic drift
tends to REMOVE VARIATION
- Probability that a particular allele will eventually be fixed (or lost) is
proportional to its frequency in the population
, What does drift do to genetic diversity? (One word) Ans✓✓✓Reduces
3 main features of genetic drift Ans✓✓✓- loss of genetic variation
results WITHIN populations (1 allele will eventually be lost or fixed)
- Genetic divergence results BETWEEN populations (populations
become more different by chance)
- Drift CAUSES evolution, but NOT adaptive evolution
Fitness Ans✓✓✓expected reproductive success of an individual with a
particular phenotype (or genotype)
3 components of fitness Ans✓✓✓- survival to reproductive age
- mating success
- fecundity
Absolute fitness equation Ans✓✓✓(probability of survival) * (average
number of offspring)
Relative Fitness Ans✓✓✓Fitness of a genotype standardized by
comparison to other genotypes
