Stickleback Practice Test

These questions are part of the practice quiz. Start practicing

• Which of the following statements about the measurement of plate number is true?
• Which statement best summarizes the genetic architecture of stickleback adaptive divergence?
• Which pair of loci is commonly cited as major-effect drivers in stickleback adaptive radiation?
• In population genetics, what concept explains why marine populations already carry freshwater-adapted alleles that facilitate colonization of freshwater?
• Which scenario demonstrates a QTL hotspot influencing armor evolution?
• Which defensive features are typical for ocean-dwelling sticklebacks?
• What evidence links lateral plate reduction to changes in the EDA regulatory region?
• Which trait is primarily used to distinguish marine and freshwater stickleback populations in classic armor studies?
• Which data source is commonly used to perform morphometric analysis in sticklebacks?
• Why might trait divergence differ between lakes that experience similar selective pressures?
• What is the purpose of a genetic variance-covariance matrix, or G matrix, in trait evolution studies?
• Stickleback adaptive radiation shows major-effect loci contributing to phenotypic divergence.
• If a freshwater population shows strong plate reduction, what study design would best test if this trait is under directional selection?
• Propose a study design to test whether Eda allele frequency correlates with plate number across marine and freshwater populations.
• How would you test for assortative mating between benthic and limnetic ecotypes?
• Which lake lies between Bear Paw Lake and Frog Lake just to the north?
• Which laboratory techniques are commonly used to genotype the Eda locus in sticklebacks?
• Which genomic technique would best identify candidate genes for armor variation in sticklebacks?
• Which scenario best explains how a founder effect could drive divergence in armor traits in a newly established freshwater lake population?
• Pitx1 gene is involved in which of the following?
• Which trait is commonly used as a proxy for diet adaptation in sticklebacks?
• What is a model organism?
• What is the purpose of using random samples in research studies?
• How many dorsal spines and pelvic spines does the threespine stickleback possess?
• Which environmental factor besides predators might explain differences in pelvic spine development between Bear Paw Lake and Frog Lake, and how would you test it?
• What type of data do fossils primarily provide in studies of evolution?
• Sea-run sticklebacks are described as anadromous. What does this mean?
• What is the main difference between Bear Paw Lake and Frog Lake as described by Dr. Bell?
• What does partial reproductive isolation imply in stickleback populations?
• Which statement best summarizes Pitx1's role as described in the material?
• Which are potential ethical considerations specific to collecting wild sticklebacks for study?
• The spines of the stickleback are modified forms of which body part?
• Give an example of sampling bias.
• Why is including both marine and freshwater populations important when studying stickleback evolution?
• What does fossil evidence suggest about the timing of pelvic spine loss in ancient lake populations?
• Which gene is most directly linked to the loss of lateral plates in freshwater sticklebacks?
• What does a PCA showing two clusters labeled by ecotypes imply about gene flow?
• Why does predation pressure influence armor evolution in sticklebacks?
• Armor plating variation in sticklebacks is primarily influenced by which gene?
• In the threespine stickleback, how many dorsal spines are present and where are the pelvic spines located?
• What are two examples of major-effect loci mentioned for stickleback divergence?
• What genetic mechanism underlies pelvic spine reduction in freshwater sticklebacks?
• How were the fish used in this lab captured?
• What are the fitness trade-offs associated with heavy armor in sticklebacks?
• The genetic architecture of stickleback divergence commonly involves major-effect loci that contribute to large phenotypic differences.
• Which gene is identified as involved in the formation of the pelvic spines in stickleback fish?
• What does genomic architecture of adaptation refer to in sticklebacks?
• Name the gene commonly linked to pelvic girdle reduction in freshwater sticklebacks and describe the resulting phenotype.
• How would you test whether the ancient Nevada lake contained predatory fish?
• What is a common method to test whether plate variation is due to plasticity or genetic differences?
• What can we infer from the stickleback fossil record about evolutionary processes occurring today?
• What is one advantage of studying larger-sized samples?
• What information can fossil and living populations reveal about pace of adaptive changes?
• What is a 'ghost of selection' concept in evolutionary genetics?
• What is the typical mode of fertilization in sticklebacks during reproduction?
• To map Eda's effects on plate number, which cross design is appropriate?
• Which factor is least relevant to explaining rapid, repeated armor reduction across freshwater stickleback populations?
• In this research, random sampling is used to ensure what about the collected specimens?
• How can phenotypic plasticity complicate interpretation of plate counts across environments?
• Natural selection can drive the evolution of which type of traits in organisms?
• Which morphological trait is most strongly associated with diet specialization in sticklebacks?
• Distinguish standing genetic variation from new mutations in the context of stickleback adaptation.
• How do predator communities drive parallel evolution in sticklebacks?
• What might explain differences between Bear Paw Lake and Coyote Lake results and Dr. Bell's results when more than 100 fish per lake were examined?
• Which statement about fossil stickleback data and Pitx1 is most plausible?
• Which gene's regulatory region is implicated in controlling plate number variation in freshwater sticklebacks?
• What evidence supports repeated, independent evolution of a trait in sticklebacks?
• Pelvic reduction in freshwater sticklebacks is associated with what genetic change in the pelvis?
• How can habitat age influence the direction of stickleback adaptation?
• What is the main ecological trade-off associated with heavy lateral plates in sticklebacks?
• Why is it important to empty the used stain, destaining solution, and water under a fume hood?
• What is the advantage of having many postglacial lakes for stickleback research?
• How does the presence of freshwater-adapted alleles in marine populations influence postglacial recolonization dynamics?
• What is one key rationale for using sticklebacks as a model for studying rapid adaptation?
• How can evolutionary processes that we measure today inform interpretations of evolutionary changes seen in the fossil record?
• Based on Experiment 2, what can be inferred about predation and pelvic spine frequency in the Nevada lake population?
• How do your data compare to those obtained by Dr. Bell and colleagues?
• Pelvic reduction in sticklebacks is studied because:
• What is the null hypothesis for the pelvic spine frequency in stickleback populations?
• How would you design a study to test for selection on gill raker length across habitats?
• Which statement accurately reflects pelvic girdle variation described for sticklebacks?
• How can selection be distinguished from drift using allele frequency data in sticklebacks?
• Which statement best defines natural selection?
• Why can freshwater sticklebacks evolve armor reduction rapidly in a few thousand years?
• In sticklebacks, what does a repeatable pattern of adaptation involving the Eda gene indicate about armor reduction in freshwater stickleback populations?
• What does FST primarily assess in population genetics?
• What is the significance of 'standing variation' versus 'new mutations' in repeated stickleback adaptation?
• Which statement correctly identifies the function of spines as armor in sticklebacks?
• Adaptation to freshwater environments in sticklebacks can proceed via standing genetic variation without requiring new mutations.
• Why is it important that labels in specimen jars be made of special paper that does not disintegrate in alcohol?
• Besides the spines, what is another component of the stickleback armor?
• Quantitative analysis of living populations helps infer what?
• In a classic stickleback study, how was ploidy variation ruled out as a cause of plate variation?
• How can you assess the heritability of plate number in sticklebacks?
• How could a cross between marine and freshwater sticklebacks reveal epistasis for armor traits?
• Which cross design would you use to map the Eda effect on plate number?
• What is the role of the EDA regulatory region in plate variation among sticklebacks?
• How did some stickleback populations become freshwater specialists?
• How would you map a trait like plate number to a chromosome?
• Which locus is associated with pelvic reduction in sticklebacks?
• What morphological changes are commonly observed alongside plate reduction in freshwater sticklebacks?
• In inferring historical demography, what pattern would you expect in neutral markers versus adaptive traits in sticklebacks?
• In a common garden experiment, if two populations still differ in gill raker length after rearing in the same environment, what can we conclude?
• What is the most likely conclusion about Frog Lake sticklebacks relative to marine populations based on pelvic morphology?
• Describe a common method to test for assortative mating based on armor phenotype?
• In the virtual lab, why did you compare pelvic structures of stickleback populations from two different lakes?
• How would you test whether pelvic reduction in sticklebacks is caused by changes in Pitx1 regulatory regions rather than changes in the coding sequence?
• Which of the following statements best describes how different environments influence evolution?
• Which of the following supports using sticklebacks as a model organism?
• Which statement best describes the left-biased pelvic asymmetry observed in studies related to Pitx1?
• How would you test whether the regulatory region of Pitx1 drives pelvic reduction?
• Which statement best describes the distribution of effect sizes among loci that control adaptive traits in sticklebacks?
• Which best describes a reduced pelvis in sticklebacks?
• In ecological speciation, what is the role of divergent selection in marine versus freshwater environments?
• What would be a basic experimental approach to test if Eda variation causally affects plate number?
• What is the expected effect on haplotype diversity around a gene if a selective sweep occurs?
• What role do glacial cycles play in stickleback population structure?
• Left bias in pelvic vestiges in stickleback populations is used to infer which of the following about Pitx1?
• How does the gill raker trait relate to diet breadth in sticklebacks?
• Name two ecological factors that differentiate marine and freshwater stickleback habitats and influence morphology.
• Variation in pelvic spine among lake populations suggests what?
• What is a quantitative trait locus and how is it used to study armor evolution in sticklebacks?
• Which genes are commonly cited as large-effect QTL for armor plate number in sticklebacks?
• What is the purpose of a morphometric analysis in sticklebacks, and what data are collected?
• Which statement supports the involvement of standing genetic variation in rapid armor reduction across lakes?
• In studies of mapping traits like plate number in sticklebacks, what type of data is essential alongside genotype data?
• What is transgressive segregation and how might it appear in stickleback hybrids?
• Standing genetic variation is alleles already present in a population prior to new selection pressures.
• Which is NOT a commonly cited mechanism contributing to stickleback adaptive radiation?
• Which trait shows the strongest repeatable genetic basis across freshwater sticklebacks?
• What does the limnetic ecotype of sticklebacks primarily do in their habitat?
• Direction selection on plate reduction would typically produce what pattern in the population over time?
• Which statement best describes the trade-off involved in armor investment?
• Why are the stickleback populations in Frog Lake more similar to marine and sea-run populations than to Bear Paw Lake?
• If a PCA plot shows two clusters corresponding to ecotypes, how would you interpret it?
• What is the most accurate description of applying fossil-record rates to modern populations according to the material?
• What is a key difference between the two major stickleback loci associated with armor variation, EDA and Pitx1_Pel?
• Which statement best describes studying fossil sticklebacks for evolutionary research?
• Which statement about QST is correct?
• Which approach is commonly used in genome-wide scans to identify regions under selection when comparing marine and freshwater sticklebacks?
• What is the role of standing genetic variation in rapid stickleback adaptation to freshwater?
• Which statement best describes the relationship between predator pressure and pelvic spine presence in these stickleback populations?
• The Pitx1 gene has been identified as involved in which two major traits?
• What happened as sticklebacks adapted to living exclusively in freshwater?
• Why was a line graph used to summarize the experimental results?
• When inferring historical demography, how do neutral markers compare to adaptive traits in sticklebacks?
• What describes an absent pelvis in sticklebacks?
• Researchers use variation across postglacial lakes to test how environmental conditions influence pelvic reduction.
• What is a QTL in sticklebacks used to identify?
• Which gene is commonly implicated in parallel evolution of reduced armor plates in sticklebacks?
• What morphological trait differs most consistently between marine and freshwater threespine stickleback populations?
• Which characteristics contribute to the stickleback serving as a model organism for evolution studies?
• Which anatomical feature, besides armor plates, is commonly studied in stickleback genetic analyses to understand ecological adaptation?
• In sticklebacks, variation at the Eda locus is most commonly associated with differences in what trait?
• In stickleback research, what is the primary purpose of QTL mapping?
• What term describes offspring showing trait values beyond the range of both parents due to recombination?
• How did ancestral sea-run sticklebacks come to live exclusively in freshwater?
• Pitx1's involvement in hind limb development is described in which vertebrate mentioned?
• In population genetics, what is the typical long-term effect of advantageous variants?
• In freshwater stickleback populations, one common evolutionary change is pelvic reduction.
• What is a common pitfall when interpreting plate number data across populations?
• What is a genetic variance-covariance matrix, or G matrix, and why is it relevant to stickleback evolution?
• Which factor drives rapid, repeated, and predictable phenotypic divergence in stickleback adaptive radiation?
• What findings would indicate polygenic control of armor traits?
• Which genetic element is primarily responsible for pelvic spine variation in sticklebacks?
• To test the hypothesis that freshwater mineral content influences spine development, which measurement would be most informative?
• Which fossil observation supports Pitx1 involvement in pelvic spine loss in ancient lake populations?
• QTL mapping is used for in stickleback studies?
• What pattern is observed in the genomic region surrounding the EDA gene in freshwater stickleback populations?
• How do ancestral marine alleles contribute to freshwater stickleback adaptation?
• Which approach best tests whether jaw shape variation reflects ecological adaptation rather than random drift?
• Which gene is most famously associated with armor plating variation in sticklebacks, and what phenotype does its freshwater variant cause?
• In a population, what happens to individuals that are better adapted to the environment in which they live?
• What is a practical reason to use cross populations to locate genomic regions associated with a trait?
• How does gene flow influence local adaptation in sticklebacks?
• Which experimental approach involves rearing marine and freshwater populations in a common environment?
• What is the purpose of testing for selection versus drift across independent populations rather than a single population?
• Which trait besides armor plates is often examined in stickleback genetic studies to understand ecological adaptation?
• Why might high energy costs of armor be selected against in small or young sticklebacks?
• Why are sticklebacks a good system for studying early steps of speciation?
• Why do some stickleback populations lack pelvic spines?
• In sticklebacks across lakes with similar ecological pressures, parallel evolution is typically seen as:
• Examine the pelvic score data. Does the pelvic phenotype differ between Bear Paw Lake and Frog Lake fish?
• How can gene flow influence adaptation in sticklebacks?
• Which loci are recognized as major-effect in stickleback adaptive divergence?
• Which methods provide important evolutionary insights?
• Which type of genetic variation is most associated with rapid, repeatable divergence in sticklebacks?
• How does the EDA pathway affect the development of lateral plates?
• What evolutionary process explains repeated, independent reductions in lateral plates across freshwater sticklebacks?
• Describe a scenario in which pelvic reduction could be maladaptive.
• Why is random sampling used when collecting specimens for this type of population study?
• Why are random samples used in most research studies?
• In PCA, which statement describes how population structure is typically visualized in sticklebacks?
• What does parallel evolution mean in sticklebacks, and give an example regarding armor plating?
• Which statement best describes the morphological differences between benthic and limnetic sticklebacks?
• Describe the standard male parental care behavior observed in breeding sticklebacks.
• Left-right bias in pelvic vestiges can be used to infer involvement of which gene?
• Complete pelvis describes which anatomy?
• In Pitx1 knockout mice, what is observed about hind limbs and pelvic structures?
• Which statement correctly distinguishes benthic and limnetic ecotypes in freshwater sticklebacks?
• Which genomic pattern would support rapid adaptation via standing variation?
• In lakes with dragonfly larvae as predators, what is the effect of pelvic spines on predation?
• Which of the following is a reason for collecting specimens by random sampling in this type of research?
• What is the role of pelvic spines in stickleback populations with respect to predation?
• What is the effect of habitat age on the trajectory of freshwater stickleback adaptation?
• How does a 'common garden' help differentiate genetic versus environmental causes of trait differences?
• Which statement best describes armor differences among stickleback populations?
• Which statement correctly pairs the function of the major armor loci EDA and Pitx1_Pel?
• Which experimental design would best isolate genetic versus environmental effects on gill raker traits?
• What is pleiotropy, and how might it influence stickleback adaptation?
• Which gene is commonly associated with variation in armor plate number in sticklebacks?
• Pel is the pelvic enhancer of which gene?
• How does the stickleback armor defend against predation?
• How can you reduce observer bias when taking morphological measurements?
• In Experiment 2, you calculated the rate at which the percentage of fish with a complete pelvis decreased in an ancient lake. Which statement best reflects applying that rate to modern fish populations?
• Did all Alaska lake stickleback populations undergo exactly the same evolutionary changes during freshwater adaptation?
• What is the overall objective of Experiment 1 in the stickleback study?
• What role do glacial cycles play in stickleback population structure?
• If left pelvic vestiges are larger in a population, what does this suggest about Pitx1's role?
• Why is nest site selection important for stickleback reproduction?
• Do you agree or disagree with the statement that living populations reveal mechanisms of selection while fossils provide a record of change over time?
• In multiple freshwater populations showing plate loss, what genetic pattern would most strongly indicate parallel evolution?
• How might selection on armor traits interact with reproductive success?
• What is a QTL hotspot, and why is it relevant to stickleback armor evolution?
• How does predator regime influence stickleback armor evolution?
• What does FST measure in stickleback population comparisons?
• Which phenotype is associated with Pitx1 variation in freshwater sticklebacks?
• Why are freshwater sticklebacks often used as a model for rapid adaptation?
• How does the PITX1 pelvic enhancer mutation affect pelvic spine development?
• Which method best quantifies jaw shape differences between limnetic and benthic stickleback ecotypes?
• How is pelvic spine reduction measured in field studies?
• Which statement about standing variation and gene flow is most accurate for trait divergence across lakes?
• Which trait is commonly examined when discussing the genomic architecture of adaptation in sticklebacks?
• Why is swapping regulatory regions used to test Pitx1's role in pelvic reduction rather than swapping the coding sequence?
• How has parallel evolution manifested in stickleback armor traits across independent freshwater populations?
• Which statement best describes the trajectory of the stickleback population in the ancient lake now known as the Truckee Formation?
• Which approach best determines whether observed trait divergence is due to selection or drift?
• What is the role of statistical analysis in population studies?
• Which type of genetic variation is emphasized as enabling rapid and repeated phenotypic divergence in sticklebacks?
• Which measurement scenario is true regarding plate counting in sticklebacks?
• How do FST and QST differ in population genetics analysis?
• Which lake is more likely to show predator-driven trait variation due to predation pressure?
• Why is it significant that Eda explains a major proportion of plate variation across multiple populations?
• What best describes epistasis in sticklebacks?
• What data would you collect to test for sensory bias in mate choice related to armor in sticklebacks?
• Which outcome would support assortative mating based on armor phenotype?
• What does parallel evolution in sticklebacks demonstrate about evolutionary processes?
• If a freshwater population shows intermediate plate numbers, which evolutionary scenario could explain it?
• Why is the stickleback a model organism for studying evolution?
• What ethical considerations must be addressed when conducting stickleback experiments?
• What is a potential consequence of sampling bias that overrepresents daring individuals?
• How would you quantitatively measure plate number and spine length in sticklebacks?