Unit 3 Lecture 5

Look at the Venn diagram and numbered statements shown above. Which of the statements on the Venn diagram are INCORRECTLY placed? 1. Results in evolution 2. Conceptually similar to "luck of the draw" 3. Non-random 4. Increases the average fitness of a population 5. Stronger in small populations than in large populations 6. Requires heritable variation 7. Differential survival and reproduction based on chance 8. Differential survival and reproduction based on how well-suited a characteristic is to the environment Natural Selection: 1, 4, 8 Both: 3, 6 Genetic Drift: 2, 5, 7 A) 1, 3 B) 3, 4, 7, 8 C) 2 ,3, 4 D) 1, 2, 6 E) 1, 3, 7, 8

A) 1, 3

Which of the following is/are absolutely necessary for natural selection to occur? A. Heritable variation B. Adaptation C. Competition D. All of the above E. None of the above

A. Heritable variation

1. Natural selection does NOT require environmental change. 2. Natural selection is a non-random process. 3. Natural selection is NOT the only mechanism of evolution. 4. Populations can adapt genetically to environmental change. 5. Biological fitness refers to healthy, strong, large, and/or sexy individuals. 6. Not using traits for many generations will cause them to be lost. 7. More evolution will occur when populations are in need of new traits to survive. 8. Genetic variation is required for natural selection to occur. 9. Selection and drift decrease genetic variation in populations. 10. Populations showing no change over time in average phenotype can be experiencing natural selection. Which of the ten statements above are FALSE? A. Only statements 5, 6, and 7 are false. B. Only statements 5, 6, 7, and 10 are false. C. Only statements 1, 2, 5, 7, and 10 are false. D. Only statements 1, 3, 5, 6, and 9 are false. E

A. Only statements 5, 6, and 7 are false.

Genetic drift can do all of the following EXCEPT 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. result in loss of alleles from a population

A. cause a population to be better adapted to its environment

1. Natural selection does NOT require environmental change. 2. Natural selection is a non-random process. 3. Natural selection is NOT the only mechanism of evolution. 4. Populations can adapt genetically to environmental change. 5. Biological fitness refers to healthy, strong, large, and/or sexy individuals. 6. Not using traits for many generations will cause them to be lost. 7. More evolution will occur when populations are in need of new traits to survive. 8. Genetic variation is required for natural selection to occur. 9. Selection and drift decrease genetic variation in populations. 10. Populations showing no change over time in average phenotype can be experiencing natural selection. Which of the ten statements above are TRUE? A. Only statements 1, 2, 3, 4, 5, 6, and 8 are true. B. Only statements 1, 2, 3, 4, 8, 9, and 10 are true. C. Only statements 2, 3, 5, 6, 8, and 9 are true. D. Only statements 1, 2, 5, 6,

B. Only statements 1, 2, 3, 4, 8, 9, and 10 are true.

Which of the phrases below is INCORRECTLY matched? A. Random process: genetic drift only. B. Stronger in larger populations: genetic drift only. C. Results in adaptation: natural selection only. D. Decreases genetic variation: both drift and selection. E. Causes evolution: both drift and selection.

B. Stronger in larger populations: genetic drift only.

Where should "Results in changes in allele frequency" go? Natural selection only Both natural selection and genetic drift Genetic drift only Neither natural selection nor genetic drift

Both natural selection and genetic drift

Which of the phrases below is CORRECTLY matched? A. Random process: both drift and selection. B. Stronger in smaller populations: natural selection only. C. Results in adaptation: both drift and selection. D. Decreases genetic variation: both drift and selection. E. Causes evolution: natural selection only.

D. Decreases genetic variation: both drift and selection.

Natural selection can do all of the following EXCEPT A. change the frequency of phenotypes that affect the fitness of individuals B. increase the degree to which a population's average phenotype fits its environment C. maintain a phenotype at a constant average in the population through time D. decrease the average fitness of individuals in the population

D. decrease the average fitness of individuals in the population

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 Decreasing the population size Increasing the population size Decreasing the strength of natural selection

Decreasing the population size

Which of the following is both a pattern and a process? Evolution Genetic drift Natural selection Natural selection Recombination

Evolution

Both the processes of natural selection and drift involve the random survival of individuals or alleles.

False

Chance is involved in the variation production process in genetic drift but not in natural selection or sexual selection.

False

If a fungal disease quickly spreads through a population of oak trees and a small number of individuals survive but the presence of a specific allele strongly predicts individual survival, this is an example of genetic drift.

False

The process of natural selection results from the survival needs on an individual, but the process of genetic drift does not.

False

The process of natural selection, but not genetic drift, results in evolution.

False

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. 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.

Fish carrying mutations causing reduction of eyes had greater survival and reproduction than normal fish resulting in the loss of eyes over time.

Where should "Completely random process" go? Natural selection only Both natural selection and genetic drift Genetic drift only Neither natural selection nor genetic drift

Genetic drift only

Which of the following is FALSE about genetic variation in a population of long-lived mammals? 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)

Genetic variation can be increased in a population by genetic drift.

Which of the following is necessary for a population to evolve? Environmental change Heritable variation Natural selection Sexual selection

Heritable variation

Which of the following sets of phrases are CORRECTLY matched? Random process: both genetic drift and natural selection. Stronger in larger populations: genetic drift only. Increases fitness: natural selection only. Associated with decreases in genetic variation: genetic drift only. Causes evolution: natural selection only.

Increases fitness: natural selection only.

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 Migration into the population of individuals with body size variation An effect of body size on individual survival or reproductive success

Migration into the population of individuals with body size variation

Where should "Increases the average fitness of a population" go? Natural selection only Both natural selection and genetic drift Genetic drift only Neither natural selection nor genetic drift

Natural selection only

Which of the following processes caused lactase mutations to originate in human populations that used dairy products? Environmental pressures Evolutionary pressures Selective pressures All of the above None of the above statements are true

None of the above statements are true

Which of the following statements is TRUE? Natural selection has a random component but genetic drift does not. Advantageous alleles cannot be removed from the population by genetic drift. Genetic drift usually results in adaptation of a population to its environment. An individual's phenotype determines whether it will survive genetic drift. None of the above statements are true.

None of the above statements are true.

Which of the following statements about genetic drift is TRUE? The action of genetic drift cannot alter allele frequencies in a population 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

The smaller the population size, the more likely genetic drift is to occur

A body cell from a daughter and mother typically have the same number of chromosomes.

True

Allele frequencies in a very large population of antelope changing by chance from one year to the next is due to genetic drift.

True

Brain cells and skin cells in the same person express different proteins.

True

Brain cells and skin cells in the same person have the same number of alleles.

True

Random allele frequency changes are expected to be larger in small populations than in large populations.

True

The direction of an allele frequency change (up or down) that occurs when a population is suddenly reduced to a very small size is not predictable.

True

The following pattern can result from natural selection: Over hundreds of generations, the mean phenotype in a population does not change very much.

True

The process of natural selection, but not genetic drift, can result in adaptation.

True

Natural selection can do all of the following EXCEPT: result in the evolution of phenotypes that decrease fitness act on phenotypes that impact the fitness of individuals in a population result in a population that is better suited to its environment result in no change to the mean of a phenotype in a population result in loss of alleles from the population

result in the evolution of phenotypes that decrease fitness