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Chapter 8

Which of the following choices is NOT an important consideration when choosing a gene for phylogenetic sequence analysis?
The marker gene should be present in multiple copies due to duplication events in the organisms of interest.
For natural selection to be operating in a population, one of the things that must be present is a particular trait that must be capable of being passed on from parents to offspring. Another word for this is:
Evolution is defined as
a change in the frequency of alleles in a population over time
"Survival of the fittest" may be a misleading phrase to describe the process of evolution by natural selection because
survival matters less to natural selection than reproductive success does.
When a sudden change in the environment, such as a flood or fire, reduces the size of a population, the survivors' collective gene pool will be only a limited representation of what was present before the disaster. This phenomenon is called:
the bottleneck effect.
In examples of convergent evolution, it can be demonstrated that organisms of the two groups that converged:
occupy similar environments.
Darwin's observations while traveling on the Beagle helped him develop which theory?
That species might change over time.
If evolution has occurred:
the allele frequencies in a population have changed.
_____________ selection favors organisms with phenotypes that are at one extreme relative to the average phenotype.
Examples of evidence demonstrating the occurrence of evolution?
molecular biology
comparative anatomy and embryology
the fossil record
In humans, random mating is most likely to occur for which of the following characteristics?
blood type
Most mutations are
random with respect to the environmental needs of the organism in which the mutation takes place.
The age of a fossil can often be determined using radiometric dating of the rocks in which the fossil is found. Because uranium-238 has a half-life of 4.5 billion years, it means that:
a uranium-containing rock that is 4.5 billion years old would, today, have only about half as much of its uranium in the form of radioactive uranium-238 as a rock that was just recently formed.
A breeder of thoroughbreds selects only the fastest horses for breeding stock. This is an example of artificial ____________ selection.
What is the difference between artificial selection and natural selection?
Artificial selection requires human intervention, whereas natural selection does not require human intervention.
Genetic variation can be maintained in populations through all of the following processes
disruptive selection.
the accumulation of neutral mutations.
environmental variation.
necessary for the evolution of a trait by natural selection?
heritability of the trait
variation in fitness due to variation in the trait
trait variation
an example of a vestigial structure?
Human appendix, molars in bats with liquid diets, eye-socket in deep sea fish
Why is it that creationism can never be accepted as a scientific explanation of the origin of life?
Because the ideas of creationism cannot be tested through experiment and observation.
___________ can result from many processes, including ___________ and __________.
Evolution; mutation; immigration
Which of the following is the best measure of an organism's fitness?
the number of fertile offspring it produces
mechanism of genetic change in populations?
natural selection
genetic drift
Evolution occurs:
only via natural selection, genetic drift, migration, or mutation.
How does an organism gain new gene functions?
Duplication of an existing gene followed by mutation and selection.
types of natural selection
stabilizing selection.
artificial selection.
directional selection.
disruptive selection.
unequal crossing over
If a new substitution arises in one copy of a highly repeated gene, it can be eliminated by unequal crossing over.