BIO 201 Quiz 3
Which of the following is required for natural selection to occur in a population?
Migration into the population Migration out of the population (ANS): Genetic variation A changing environment A large population size
Which of the following is NOT necessary for body size to evolve in a population of crickets by natural selection?
Variation in body size among individuals in the population Heritable variation in body size among individuals in a population (ANS): Migration into the population of individuals with body size variation An effect of body size on individual survival or reproductive success
Which of the following is the random component of natural selection?
(ANS): The occurrence and types of mutations The survival of different genotypes The fertility of different genotypes The reproductive success of genotypes None of the above
Why is the overall process of natural selection non-random?
Because without it organisms could not be perfectly adapted to their environment Because the location and frequency of mutations in the genome are non-random (ANS): Because the organisms that survive and reproduce are a non-random subset of a population Because the environment often causes mutations that tend to be helpful to the survival of some individuals
Which of the following is most likely to increase the strength of genetic drift in a population of mice?
Decreasing the amount of food available (ANS): Decreasing the population size Increasing the population size Decreasing the strength of natural selection
Which of the following sets of phrases are CORRECTLY matched?Genetic drift only Natural selection only Both drift and selection
1. Random process: both genetic drift and natural selection. 2. Stronger in larger populations: genetic drift only. (ANS): 3. Increases fitness: natural selection only. 4. Reduces genetic variation: genetic drift only. 5. Causes evolution: natural selection only.
Which of the statements (1-10 below) are WRONG? 1. Natural selection is a non-random process. 2. Natural selection does NOT require environmental change. 3. Natural selection is the only mechanism of evolution. 4. Natural selection tries to improve the fit between phenotype and location. 5. Individuals and populations can genetically adapt to environmental change. 6. Adaptation refers to the biological process by which all members of a population gradually adjust to environmental conditions. 7. Biological fitness refers to healthy, strong, large, and sexy individuals. 8. Not using traits for many generations will cause them to be lost. 9. The need to survive causes life to change through time. 10. Genetic variation is required for natural selection to occur.
2, 3, 4, 6, 7 (ANS): 3, 4, 5, 6, 7, 8, 9 2, 3, 5, 6, 7, 8, 9 1, 2, 3, 4, 5, 6, 7, 10 All of them are wrong
Which of the following statements are TRUE?
A population with high genetic variation is only possible when many new mutations occur. (ANS): Speciation is only possible when there is low or no gene flow between diverging populations. Evolution is only possible when the process of natural selection occurs among individuals in a population. All of the above are true None of the above are true.
Cases of observed differences in human lactose tolerance in different places, and cases of observed differences in wasps in different places are best described as (select all that apply):
A process (ANS): A pattern (ANS): An association A mechanism or cause A theory
What is natural selection?
A process by which genes that are selectively advantageous to fitness accumulate in an individual to increase its reproductive success A process by which new species that are well-adapted to their environment are formed A process by which genes increase or decrease in frequency in a population due to their impact on individual fitness (ANS): A process by which alleles increase or decrease in frequency in a population due to their impact on individual fitness
Most adult mammals cannot digest milk. In human populations from both northern Europe and parts of Africa adults retain the ability to digest milk. Which of the following statements about this phenomenon is FALSE?
A. Evidence indicates that this trait evolved independently in the European and African populations. B. During famines, when milk was the only reliable food source around, the ability to digest milk affected fitness. (ANS): C. When all types of food were abundant, mutations enabling adults to digest milk strongly increased fitness. D. The ancestors of both the European and African populations were not able to digest milk as adults.
What could cause one species of grasshopper to change into three species over time?
A. Groups of grasshoppers encountered different island environments so the grasshoppers needed to become new species with different traits in order to survive. (ANS): B. Groups of grasshoppers must have been geographically isolated from other groups and random genetic changes must have accumulated in these grasshopper populations over time. C. There may be minor variations, but all grasshoppers are essentially alike and all are members of a single species. D. In order to survive, different groups of grasshoppers needed to adapt to the different islands, and so all organisms in each group gradually evolved to become a new grasshopper species.
In most populations of elephants, 100% of males and about 95% of females have tusks. In several populations in Africa, the percentage of females without tusks increased during a period in which humans were hunting elephants in order to sell the ivory in their tusks. Which of the following statements about this phenomenon is TRUE?
A. In populations without hunting, individuals without tusks have lower fitness than those with tusks. B. Selection favoring females lacking tusks in these populations is due to the action of humans. C. Male tusks are subject to sexual selection in these populations of elephants. (ANS): D. all of the above
The arctic fox has a thick layer of fat under its skin that helps keep it warm in its cold climate. They do not hibernate (sleep through winter) and actively look for food all winter. At the beginning of winter they typically have about 30 days of energy stored in fat. Available evidence shows that this species of fox evolved from ancestors that lived in warmer areas and did not have a thick fat layer. What was most likely true regarding genetic mutations that occurred during the time the fox species was evolving the thick fat layer?
A. Most of the mutations helped the foxes survive in their new environment. B. The number of mutations occurring in the fox population increased when the foxes moved into the cold climates and then decreased when the foxes finished adapting to their environment. C. The mutations occurred because foxes had to adapt in order to survive and reproduce in the cold climates. (ANS): D. The mutations were not affected by temperature or the needs of the foxes.
Natural selection can do all of the following EXCEPT
A. change the frequency of phenotypes that affect the fitness of individuals B. increase degree to which a population's average phenotype fits its environment C. maintain a phenotype at a constant average in the population through time (ANS): D. decrease the average fitness of individuals in the population
Which of the following statements is TRUE?
Evolution can only occur by natural selection Natural selection means the same thing as evolution (ANS): Natural selection, by itself, cannot produce new traits Individual organisms can evolve when the environment changes None of the above statements are true
Which of the following patterns can be best explained by sexual selection?
High individual fitness in a population (ANS): Extreme sexual dimorphism in a population High genetic variation in a population A and B B and C
Which of the following would NOT be explained by the existence of sexual selection?
Large racks of antlers in male deer who successfully compete for harems (groups) of females Bright coloration in a males but not females of a bird species Choosiness in male seahorses in which females they choose to mate with (ANS): Protective coloration in male and female beetles that helps them to avoid predation A complex mating dance in male fruit flies which attracts females on flowers
(Evolution Review Quiz 2020 fig 8) Use the Venn diagram shown below. Determine if it applies to (A) Natural selection ONLY, (B) Both, (C) Genetic drift ONLY. Completely random process
Natural Selection only both (ANS): Genetic drift only
How might natural selection result in the inheritance of deleterious alleles?
Natural selection is a random process, so it can lead to any allele being inherited. (ANS): A parent with high fitness due to a beneficial allele may also have deleterious mutations which are also passed on to offspring. Most mutations are deleterious or neutral, so it is more likely that natural selection will increase the frequency of those alleles. It is not possible for natural selection to lead to the inheritance of deleterious alleles.
(Evolution Review Quiz 2020 fig 7) Use the Venn diagram shown below. Determine if it applies to (A) Natural selection ONLY, (B) Both, (C) Genetic drift ONLY. Results in changes in allele frequency
Natural selection only (ANS): both Genetic drift only
Which of the following is usually NOT included in the evolutionary concept of fitness?
Survival Number of offspring produced Ability to produce gametes (ANS): Length of lifespan after reproduction
Natural selection is non-random, but what necessary component of this process is random?
Survival Sexual selection Fitness (ANS): Mutation
Which of the following statements about genetic drift is TRUE?
The action of genetic drift cannot alter allele frequencies in a population (ANS): The smaller the population size, the more likely genetic drift is to occur Populations do not evolve due to the presence of genetic drift High levels of genetic drift can result in the formation of new deleterious mutations The frequency of a phenotypic trait cannot change due to genetic drift
A species of butterfly is poisonous to bird predators. Birds learn to avoid this species because when they attack and eat butterflies, the birds get sick. The butterfly species colonizes an island with no predators and over the next one million years gradually loses its toxicity. Which of the following is the most likely explanation for this?
The butterflies became non-poisonous because they no longer needed protection from birds. The butterflies stopped producing toxins because there were no birds attacking them. (ANS): On the island, butterflies without toxins had higher fitness than butterflies with toxins. Birds on the island no longer attack the butterflies because they expect them to be poisonous. Butterflies on the island no longer produce the toxin because it is too costly to produce.
Which of the following is random about natural selection?
The differential survival and reproduction of certain genotypes The ability for individuals of the same species to find each other and mate successfully The suitability of certain phenotypes to the conditions of the environment (ANS): The mutations that generate a population's standing genetic variation All of the above
Which of the following is an explanation that an evolutionary biologist would give to explain the loss of eyes in a species of fish that lives in dark caves?
The fish did not need to be able to see in the caves because it is dark, so it evolved into a phenotype that no longer developed eye cells and tissues. (ANS): Fish carrying mutations causing reduction of eyes had greater survival and reproduction than normal fish resulting in the loss of eyes over time. Over time, individuals transported more kilocalories (energy) to other traits than to eye development because eyes were not used. Because building eyes is energetically expensive, and the eyes could not be used, the allele was not inherited in offspring. In order to develop into a phenotype that was better adapted to living in caves, individuals mutated forms completely lacking eyes.
Natural selection can do all of the following EXCEPT:
act on phenotypes that impact the fitness of individuals in a population (ANS): result in the evolution of phenotypes that decrease fitness result in a population that is better suited to its environment result in no change to the mean of a phenotype in a population None of the above
Which of the following is generally non-random?
the location in the genome where a mutation takes place The part of a gene in which a mutation takes place The location on the chromosome where recombination occurs (ANS): The survival of individuals under natural selection The allele which an individual gamete receives
In what way can natural selection produce new traits?
"As an environment changes, organisms are forced to adapt their bodies and physiologies" "Organisms attempt to increase their fitness in any way possible, leading to the development of new and better traits" "Natural selection increases genetic diversity in a population, leading to new traits" (ANS): "Natural selection cannot, by itself, produce new traits"
Which of the following is/are absolutely necessary for natural selection to occur?
(ANS): A. Heritable variation B. Adaptation C. Competition D. All of the above E. None of the above
Genetic drift can do all of the following EXCEPT
(ANS): A. cause a population to be better adapted to its environment B. cause a change in allele frequencies in a population C. cause a change in the population average for a phenotype D. decrease the amount of genetic variation in the population
Which of the following is FALSE about genetic variation in a population of long-lived mammals?
(ANS): Genetic variation can be increased in a population by genetic drift. Genetic variation can be decreased in a population by natural selection. Most populations have huge amounts of genetic variation. Genetic variation can be generated by mutation and recombination. None of the above are false (all are true)
Which of the following is most correctly stated in scientific terms of evolutionary biologists?
(ANS): Milkweeds evolved toxin-production because ancestors producing toxins tended to survive better than those that did not produce toxins Milkweeds evolved toxin-production because other species that pre toxins were surviving better than they were Milkweeds evolved the productions of toxins because the needed to resist being eaten by insects so that they could survive longer Milkweeds produce toxic chemical compounds so that they can live longer and produce more seeds so that the population size will increase Milkweeds produce toxic chemical compounds so that insects in their environment won't eat them and will attack other plants instead
When a new mutation occurs in a gamete and the individual that develops from the zygote bearing that mutation dies because the mutation causes a problem in development, this is the result of
(ANS): Natural selection Recombination Random chance Independent assortment
(Evolution Review Quiz 2020 fig 9) Use the Venn diagram shown below. Determine if it applies to (A) Natural selection ONLY, (B) Both, (C) Genetic drift ONLY. Increases the average fitness of a population
(ANS): Natural selection only both Genetic drift only
Which of the following categories of mutations is the MOST common in an individual or population?
(ANS): Somatic mutations that have no effect on individual survival Somatic mutations that have deleterious effects on individual survival Germline mutations that have no effect on individual survival Germline mutations that have deleterious effects on individual survival Germline mutations that have positive effects on individual survival
In an evolutionary context, fitness refers to:
(ANS): The reproductive output of an individual The ability of an organism to survive The strength, size, speed, and other physical attributes of an organism The health of an organism
The origin of all new genetic variation is
(ANS): mutation recombination genetic drift natural selection independent assortment