Cumulative Quizzes (Review)
Consider a quantitative trait controlled by more than one gene as well as partially by environmental factors that occur during organism development. How would you determine the proportion of trait variation that is genetically inheritable? Select all that apply. -None of these answers are correct - Correlate mid-offspring trait value against mid-parent trait value -Subtract the trait variance at the F1 generation from the trait variance at F2 then divide this by the trait variance at F2 -Use artificial selection to determine how easily it is to select for specific traits
- Correlate mid-offspring trait value against mid-parent trait value -Subtract the trait variance at the F1 generation from the trait variance at F2 then divide this by the trait variance at F2 - Use artificial selection to determine how easily it is to select for specific traits
Fossil fuels initially formed during the __________________. -Ordovician -Mesozoic -Cambrian -None of the above -Cretaceous
- None of the above
Consider a population that is split in two by a geological event that changes the course of a river. Over time, mutations occur in both populations that lead to the mating calls of each population becoming different. Later, the populations come into contact and are reproductively isolated. Which of the following best describes what occurred in this scenario? Select all that apply. -Allopatric speciation -Peripatric speciation -Behavioral barrier -Sympatric speciation -Mechanical isolation -Vicariance -Epistatic interactions
-Allopatric speciation -Behavioral barrier -Vicariance
Which of the following describes the logic behind the asymmetry between biological males and biological females that is thought to lead to sexual selection? Select all that apply. -Male traits are thought to be more strongly affected by sexual selection than females. - Per unit cell, sperm requires less matter and energy to produce than do eggs. -Males are a limiting resource for females -Per unit cell, eggs require less matter and energy to produce than sperm. -Females are a limiting resource for males
-Male traits are thought to be more strongly affected by sexual selection than females. -Per unit cell, sperm requires less matter and energy to produce than do eggs. -Females are a limiting resource for males
Which of the following is considered a "cost of sex"? Select all that apply -With sex and meiosis, lethal alleles are separated from adaptive ones -With sex and meiosis, mutator alleles are separated from beneficial alleles -Per reproductive event, asexual reproduction is less than sexual reproduction -Per reproductive event, asexual reproduction is greater than sexual reproduction -With sex and meiosis, two beneficial alleles can become separated
-Per reproductive event, asexual reproduction is greater than sexual reproduction -With sex and meiosis, two beneficial alleles can become separated
Here again are the details of question 5: Consider the following scenario. A population of 80 gophers live in a farmer's cabbage field. Using traps called "gophinators" the farmer kills approximately 40 of the gophers over the course of a year. The remaining gophers mate and produce 30 offspring that survive to adulthood. During the next year the farmer kills approximately 35 gophers... five more than the first year. The details in this scenario describe that the gophers are evolving due to natural selection .... nature in this case being the farmer and her gophinators. Which of Darwin's postulate were not met given the details provided in this scenario? Select all that apply -Postulate 2 - Variation is heritable -Postulate 4 - With respect to the variable trait in question, survival and reproduction are non-random -No other answer is correct - All postulates were met -Postulate 1 - Population varies
-Postulate 2 - Variation is heritable -Postulate 4 - With respect to the variable trait in question, survival and reproduction are non-random -Postulate 1 - Population varies
Suppose there is a single bird population living in the same ecosystem and occupying the same range. A few males in the population start singing a mating song at a faster frequency than other males in the population that sing at a slower frequency. Some females prefer the song and mate with the faster frequency males, while other females do not. Over time the fast singing males (and the females that prefer them), become reproductively isolated from the slow-singing population. Which of the following has occurred? Select all that apply. -Allopatric speciation -Sympatric speciation -Behavioral reproductive barrier -Ecological reproductive barrier -Peripatric speciation -Gametic reproductive barrier -Vicariance
-Sympatric speciation -Behavioral reproductive barrier
What factors might cause linkage disequilibrium? Select all that apply -recombination is high -The population is young -A new mutation is automatically in linkage disequilibrium - Natural selection random mating - genetic drift
-The population is young -A new mutation is automatically in linkage disequilibrium -Natural selection - genetic drift
Consider the scenario where a particular behavior has a cost of 1 fitness units, and a benefit of 4 fitness units. Which of the following situations do you predict to find this behavior? Assume typical relatedness as it's found in humans. Select all that apply. -between half-siblings -between parent/offspring -between siblings -between second cousins -between first cousins
-between parent/offspring -between siblings
What maintains linkage disequalibrium? Select all that applies -founder effect -Natural selection - Low amounts of recombination -Sex -Inbreeding
-founder effect -Natural selection -Low amounts of recombination -Inbreeding
Which of the following types of mutations always have no affect on protein function? Select all that apply. -nonsynonymous mutations -gene duplication due to unequal crossing over during meiosis -point mutations to regions of the genome that do not code for protein -frameshift mutations -synonymous mutation -nonsense mutations
-gene duplication due to unequal crossing over during meiosis -point mutations to regions of the genome that do not code for protein -synonymous mutation
Which of the following types of mutations might result in a change to protein function? Select all that apply.
-nonsense mutation -frameshift mutation - non-synonymous mutation
Suppose there is a population with a simple Mendelian trait with two alleles, B and b. If there are 1000 individuals in the population, and ten individuals have the recessive "bb" genotype, what is the frequency of the B allele? Assume the population is in Hardy-Weinberg Equilibrium.
0.9
Multicellularity evolved ________________ times independently.
5
Suppose a bee stings you, and the bee dies. Explain this behavior evolutionarily in 2-3 sentences.
A honey bee worker's sting is spite and follows from kin selection. It drives the non-relative from the hive, thus allowing the bee's relatives to higher fitness.
In no fewer than three sentences, differentiate between adaptation and acclimation.
Adaptations may not be necessary for survival. Acclimation is a response developed by an organism to target a specific stressor in an environment. Adaptation is more long-term and permanent to a group of organisms. adaptation is genetic, acclimation is not.
In the Barrett et al. paper, the study showed that a mutation to the ____________________ allele resulting in lighter dorsal fur color had higher fitness on lighter sand.
Agouti
Describe how if Darwin's four postulates occur (and can be documented) we can say that natural selection occurred.
All postulates must occur for natural selection to occur. The first has to show there are enough variations within a population, with the second showing those can be passed down. The third and fourth have to occur to have those traits survive in the population, thus showing the adaptations via natural selection.
Consider the phylogeny below based on differences in a hypothetical gene sequence, and assume it was done correctly from a methodological perspective: Assuming the species designation for Cactus finch and Medium ground finch is correct (i.e. they are indeed different species), explain why one might find this result
Both samples of the cactus finch have a common ancestor to share at node c, whereas one of the samples for the medium ground finch separates at node b, confirming different species. *****But why is med finch sample 1 nested within cactus? provide a hypothesis such as incomplete lineage sorting.***** Horizontal gene transfer?
In four or five sentences, describe the general pattern of the history of life across the fossil record.
Certain taxa share a common ancestor more recently than others. Many histories of organisms are well known from the fossil record, but some aren't, thus the record is incomplete. Detailed records show some characters change gradually, while some are punctuated. Macroevolution is a large evolutionary change over geologic time with lots of transitory fossils in the record. Macroevolution examples include: the origins of tetrapods, origins of birds, origin of mammals, origins of cetaceans, and origins of hominids. The "general pattern" across the whole thing is extinction and adaptive radiation.
In 3-5 sentences, describe the general pattern of the fossil record through time. How does diversity vary through time? And what processes cause this?
Certain taxa share a common ancestor more recently than others; many histories of organisms are well known from the fossil record, but some aren't, thus the record is incomplete. Detailed records show some characters change gradually, while some are punctuated; diversity fluctuates. Macroevolution is a large evolutionary change over geologic time with lots of transitory fossils in the record. Macroevolution examples include: the origins of tetrapods, origins of birds, origin of mammals, origins of cetaceans, and origins of hominids. The general pattern across the whole thing is extinction and adaptive radiation.
In one sentence, state the technical definition of biological evolution.
Change in allele frequencies of a "group of organisms" over the course of generations.
Consider a quantitative trait controlled several genes. If the phenotype at the edge of the distribution has higher fitness than phenotypes at the center or the other end of the distribution, what type of selection do you predict will occur?
Directional selection
According to the fossil record, animal phylum diversity is currently the highest level it has ever been.
False
All traits are adaptations.
False
Carbon dating is used to determine the absolute age of a fossil.
False
Consider a population that can reproduce either sexually or asexually. Given our study understanding of the evolutionary benefits of sexual reproduction, a population with a lot of pathogens in their environment should have a lower proportion of males than a population without many pathogens in their environment.
False
Consider the following scenario. A population of 80 gophers live in a farmer's cabbage field. Using traps called "gophinators" the farmer kills approximately 40 of the gophers over the course of a year. The remaining gophers mate and produce 30 offspring that survive to adulthood. During the next year the farmer kills approximately 35 gophers... five more than the first year. The details in this scenario describe that the gophers are evolving due to natural selection .... nature in this case being the farmer and her gophinators.
False
In order for evolution to be accepted as correct, we must be able to show exactly how chemical evolution (i.e. the formation of organic biomolecules from simple inorganic substrates) occurred.
False
Predators caused the mutations in rock pocket mice that resulted in the black fur color on the dark lava background.
False
Suppose we have a population with a quantitative trait. If we plot the relationship between mid-parent value against mid-offspring value, and the result is weak correlation (i.e. R2 close to 0), then this is evidence that the trait is heritable.
False
In two to three sentences, explain the following: why is it difficult to differentiate between evolution "for" a trait and evolution "of" a trait? (i.e. why can't we assume that a function a trait is used for now wasn't the function that originally resulted in higher fitness when selection occurred?)
Features can have consequences for functions that were not selected for originally. Since natural selection is goalless, hitchhiking can occur.
Describe the findings reported by Karmin et al. In particular, include in your answer an explanation regarding why a bottleneck is detected in the chromosome but not in mtDNA. In other words, why is there a bottleneck in our (all living humans) biological male ancestry but not in our biological female ancestry?
Female Ne is lower than male Ne. The bottleneck of the Y chromosome was altered by cultural changes which varied the amount of reproductive success among males in a population.
Describe your understanding of gene flow. How does fitness influence gene flow? How might genetic diversity (heterozygosity) be effected by gene flow?
Gene flow is the movement of genes into or out of a population. Migration can alter allele frequencies in local populations, and a high level of gene flow has greater genetic diversity. Gene flow is random with respect to fitness.
In 3-4 sentences, compare and contrast how genetic drift operates in a small versus a large population. What happens to genetic diversity (heterozygosity)? How does fitness influence genetic drift?
Genetic drift is the change in allele frequencies due to random events in the environment and effect is stronger in small populations. Genetic drift is random with respect to fitness. Drift always reduces genetic variation and operates slower in large populations than in smaller ones.
Consider a simple Mendelian trait controlled by a gene with two alleles: A and a. If Aa has higher fitness that either AA or aa, what type of selection do you predict will occur?
Heterozygote advantage
In no fewer than three sentences, explain the Out of Africa hypothesis explaining the origin of modern humans.
Hominin fossils have primarily originated in East Africa with several transition features. Homo erectus was the first population to expand out of Africa, and it radiated into six species; only one survived, which is us! The Out of Africa hypothesis is a model for the origin and dispersal of modern humans.
Why is human skin color so variable?
Human skin color evolved from what UV radiation we originate. The closer to the equator, the darker skin pigmentation is, and vice versa. This is due to what your body needs: if your skin color originated closer to the equator, it requires more vitamin D if you live further from it. You have different amounts of melanin depending on where you originate. ****"UV radiation we originate"? Why light skin for some people? explain.****
Who influenced Darwin by providing him the idea that populations change, rather than individuals?
Malthus
Match the mechanism of evolution with the corresponding Hardy-Weinberg assumption.
Natural Selection: No selection Genetic Drift: Infinitely large population Random mating: Non-random mating Gene Flow: No immigration Mutation: No mutation
Consider a population with a trait controlled by two alleles, C and c.... where C is fully dominant to c. Suppose that the frequency of the C allele in the population is 0.15. If there are 425 offspring in the next generation of a population in Hardy-Weinberg equilibrium, how many of those offspring resulted from the fertilization of a C" egg with a "c" sperm"? -212 -No answer is correct -108 -10 -307
No answer is correct
Suppose there is a quantitative trait in a population, that varies from small to large. If smaller trait individuals have higher fitness than larger trait individuals, what type of selection do you predict would occur? -No answer is correct -Disruptive selection -Stabilizing selection -Balancing selection -Sexual selection
No answer is correct
Which of the following changes to DNA cannot be used to determine the relatedness... and hens evolutionary history (pattern) of a group of organisms? Fussions No answer is correct Inversions Point mutations Translocations Polyploidy Retropositions Fissions
No answer is correct
Describe how natural selection could occur without evolution (i.e. a change in allele frequency in the population) occurring as a result.
Phenotypic plasticity is the primary reason why natural selection can occur without evolution. The color of a caterpillar can change with temperature, just like the sex of some reptiles is based on temperature. A bird can have different dialects of songs in different regions.
In a few sentences, describe a scenario where natural selection could occur without evolution occurring.
Phenotypic plasticity is the primary reason why natural selection can occur without evolution. The color of a caterpillar can change with temperature, just like the sex of some reptiles is based on temperature. A bird can have different dialects of songs in different regions.
Consider the following table of presence absence of four traits among five species:
Phylogeny 2
What breaks down linkage disequilibrium?
Recombination
Describe one possible outcome of a hybrid event.
Reinforcement and/or genetic incompatibility with/without selection against hybrids.
In two or three sentences, provide one of the proposed evolutionary explanations for the existence of sex. So "why sex?"
Sex increases variation through recombination. Adaptations to a fluctuating environment: recombination is favored and works faster in big populations as the environment fluctuates.
Explain why using different species concepts might give different species designations. (e.g. using biological species concept v. phylogenetic species concept or morphospecies concept).
Species are groups of actually or potentially interbreeding natural populations that are reproductively isolated from other groups. This definition (biological species concept) doesn't include most of life (like asexual organisms), so we also have to include that species are populations of individuals having the potential for phenotypic cohesion(cohesion species concept), but this can also leave out niche organisms. So at the basic level, it's a basic unit of classification. Recognition species concept is the most inclusive population of individual biparental organisms that share a common fertilization system.
In 3-5 sentences, answer the following: What is a species?
Species are groups of actually or potentially interbreeding natural populations that are reproductively isolated from other groups. This definition doesn't include most of life, so we also have to include that species are populations of individuals having the potential for phenotypic cohesion. So at the basic level, it's a basic unit of classification.
Which of the following describes why sexual selection occurs more strongly on male traits than female ones?
Sperm is energetically cheap, while eggs are energetically expensive
A social interaction where neither actor fitness, nor recipient fitness increases is called ___________________.
Spite
Consider the following scenerio of a simple Mendelian trait controlled by a gene with two alleles: A1 and A2. Now suppose the A1A2 genotype has the lowest fitness, and the A1A1 genotype has the highest fitness but is at very low frequency in the population (i.e. p = very small). What do you predict will happen?
The A1 allele will go extinct.
Describe the relationship between DNA structure and protein structure.
The DNA structure dictates protein function and information from those genes makes proteins. what about RNA?*****
Describe the relationship between DNA and protein. Provide a 1-3 sentence short answer.
The DNA structure dictates protein function. Information from genes makes proteins. Explain how RNA links DNA to protein
In one sentence, define biological fitness.
The number of offspring of an organism.
Describe your understanding of Lamichhaney et al.
The paper describes the events leading up to reproductive isolation in three generations in Darwin finches, which normally take hundreds of generations to develop. This is because of homoploid hybrid speciation.
Under the sexy son hypothesis, which of the following scenario do you predict would result in the extinction of female choice?
The variability of female choice is greater than the variability in the male trait, and the population starts higher than the equilibrium line.
Darwin's idea of how heredity worked was disproved by Mendel.
True
In Eukaryotes (like us) with large genomes that don't code for protein, most mutations do not affect fitness one way or the other.
True
Maximum likelihood is the technique that is used to determine the most accurate phylogeny for a group of organisms that does so based on the differences in probabilities between different types of mutations (e.g. purine to purine v. purine to pyrimidine).
True
Natural selection has been shown to be operating in the rock pocket mice populations with dark fur living on the dark lava.
True
Suppose there is a population with a simple Mendelian trait with two alleles, A and a. The frequency of "A" is 0.2. If there are 1000 individuals in the population and there are 180 heterozygotes, this population is evolving with respect to this trait.
True
Suppose there is an allele for a gene that is under weak positive selection (i.e. it's slighly more adaptive than other alleles for that gene). This allele is also experiencing drift. In a small population, it's more likely that this allele becomes fixed due to drift, relative to the allele in a large population.
True
The majority of the genome does not code for protein, thus the predominant mechanism that causing the genome to evolve is genetic drift.
True
Change within a lineage is termed ________________________________.
anagenesis
Social systems with reproductive division of labor, overlapping generations and care of young is termed _______________________.
eusociality
A special case of genetic drift where the allele frequencies of a new population are a function of those that are present when the population begins is called _________________________________.
founder effect
Suppose we have a population with a quantitative trait. To determine the ____________________ of the trait, we would divide the total genetic variance (VG) by the total phenotypic variance (VP).
heritability
Consider two populations of the same species. Population 1 has a higher inbreeding coefficient than population 2. Thus, __________________________________ is lower in population 1 than in population 2.
heterozygosity
Inbreeding results in a decline in ____________________________, even if allele frequencies stay the same.
heterozygosity
Suppose two different species share a trait because it arose independently in each lineage because of convergent evolution. This is termed a _____________________, and one cannot build a phylogeny using it.
homoplasy
The range of phenotypes that can be produced by a single genotype is called the
norm of reaction
Suppose there is an allele that is adaptive (giving higher fitness to those that have it, relative to those that have other alleles), and the frequency of this allele is equal to p. Which of the following situations would you predict that it would be most likely (i.e. have the highest probability of occurrence) that this allele would go extinct due to genetic drift?
p = 0.01
__________________________________ is when speciation occurs because non-disjunction during meiosis and resultant offspring have extra whole sets of chromosomes.
polyploidy
Suppose the trait of a particular lineage stays the same for a long period of time, then rapidly changes. This is termed ______________________________________.
punctuated equilibrium
A __________________ ________________ is when sequences nearby on the chromosome to an allele under selection increase in frequency through time, and may even become fixed.
selective sweep
A genetic sequence that increases in frequency because it is nearby (on the chromosome) a different gene that is under positive natural selection is said to be increasing via ________________________.
selective sweep
The hypothesis that allows for runaway selection of female choice and male display is called the ______________________________.
sexy son hypothesis
A __________________________ is where there is a sharp change in allele frequency across space, where the allele is high frequency at one end of a gradient (e.g. in the west) and low frequency at the other end of the gradient (e.g. in the east).
step cline
Consider two populations... one in the east and one in the west. These populations have a gene with two alleles, A and a. If the AA genotype has high fitness in the west, and the aa genotype has high fitness in the east, and there was little to no gene flow between populations, the frequency of these alleles would change across space showing the pattern of a ____________________________.
step cline
