Last Modified: 2012-10-26
In _____ selection, individuals with both extreme forms of a trait are at a selective advantage.
The spotted touch-me-not, a flowering plant, has seed pods that burst open when touched and forcefully eject their seeds. Such an adaptation is favorable because it√
Student Answer: A. aids in the dispersal of the species.
Which concept was not included in Charles Darwin's theory of natural selection?
Student Answer: D. punctuated equilibrium
4. Define bottleneck effect and founder effect. Explain how each differs in its effect on microevolution. √
Bottleneck effect: Genetic drift due to a drastic reduction in population size. This is when a disaster occurs such as an earthquake which may reduce a population drastically. Founder effect: The type of genetic drift resulting from that of the parent population.
Because of prolonged drought, the trees on an island are producing nuts that are much smaller with thicker and harder shells. What will happen to the birds that depend on the nuts for food? Of the three general outcomes of natural selection, this example illustrates
They will have to adapt, and have offspring who have genetic differences which will improve their chances of survival. By producing enough offspring it may assure that the population doesn't die off before the adaptation takes place. Also, in order for this to happen the offspring must have some genetic or partially heritable traits that make it good at it's job. If not the birds will die.;
The example Illustrates: Directional Selection
Does sex play a role in evolution; explain why or why not as well as how?
Sex allows for a new combination of genes to be produced every generation; this increases the chance for survival and evolution, by allowing organisms to adapt to stressors in their environment and to breed offspring who are capable, and possibly improved organisms. Sexual reproduction increases genetic variation which improves a species chances for change over consecutive generations.
Are evolution and “survival of the fittest” the same thing? Explain.
No, evolution refers to the continual changes in a population or species over time.
Survival of the fittest often called natural selection refers to the advantage, some organisms have over others because of their abilities to survive & reproduce in a certain environment.
Describe how gene flow, mutation, nonrandom mating and natural selection can cause microevolution. Define each as needed
Gene flow-tends to reduce differences in populations. It is where a population may gain or loses alleles.Mutation-Mutations are changes in the DNA sequence.random mating-When a male and female reproduce by purely by chance.natural selection-is a process when an organism with certain inherited traits
Describe the two major mechanisms of speciation: divergent evolution and convergent evolution, telling how they might occur.
Convergent Evolution-is when a different species develops specific characteristics of another species that is normally unlike. Divergent Evolution-is when a species who is usually related to another species diverges and develops different characteristics by natural selection; leading to a new species.
Huntington's disease (HD) is a dominant disorder that causes progressive deterioration of brain cells and eventually death. Even though this is a fatal disease and a dominant one, it has persisted in the human population. Explain the reason that Huntington's has not been eliminated. (You will have to look up information on the disease paying special attention to the age at which it is expressed. It is important to understand the significance of this.)
HD has not been eliminated because the symptoms usually don't effect a person until they are in their 30's or 40's. By that time they have already had kids, and passed on the disease. Studies show that 40% of people with the HD gene are asymptomatic at the age of 50. Lack of genetic testing, cause the disease to go unchecked. Also, parents who have HD are still making the decision to have children since their children, leaving their children with a 50% chance of getting the disease.
Which best describes the theory of punctuated equilibrium?
Which is most closely associated with the process of sexual selection?
Which statement is true of artificial selection?
Which statement best characterizes natural selection?
DNA evidence suggests that the closest relative to the human is the:
A group of mice becomes separated by the formation of a river. Over time, the northern mice became smaller and whiter, while the southern mice became larger and browner. This is an example of:
Who is the author of the 'Theory of inheritance of acquired characteristics'?
Which of the following conditions is necessary for speciation to occur?
The individual in a population which is considered the most fit would be
A population of rats is captured in a field, marked with a small tag on the ear, released back into a field, recaptured and then counted. Rats with long ears and short ears are selected against and are found in small numbers in the population. Rats whose ears are of medium length are found to be in large numbers in the population. What type of selection does this represent?
The appearance of a fertile, polyploid individual within a population of diploid organisms is a possible source of a new species. If this individual is capable of reproducing to form a new population, this would be considered to be an example of
The process in which a population moves into a relatively unexploited environment and then undergoes rapid evolutionary divergence to produce many separate species is called
A large number of dark and light forms of moths were captured and marked for identification. 500 dark moths and 500 light moths were released. 52 dark moths and 21 light moths were randomly recaptured. Which of the following would be the most reasonable assumption?
Which of the following is likely to have been the product of sexual selection?
The scarlet oak is adapted to moist bottomland whereas the black oak is adapted to dry upland.
A certain species of land snail exists as either a cream color or a solid brown color. Intermediately colored snails are rare.
Along the length of a river there exists a species of green sunfish. In order to provide electricity to area homes, a hydroelectric dam is built that separates the lower river area from a newly formed lake above. After many, many years, the green sunfish in the river and lake are sampled and found to be phenotypically very different. Which is the best hypothesis to explain the microevolutionary changes observed?
Which of the following statements is true?
Elephant seals have tested as homozygous for every gene so far tested. What is the most likely reason for this?
According to Charles Darwin, one factor that affects the evolution of a species is
While conducting research in the rainforest you collect a number of beetles. Several of them have similar morphologies but different coloring. How could you determine if they are members of the same species?
Speciation may arise from the evolution of different courtship displays and dances. This is an example of
According to Darwin, what are three conditions must be met in order for natural selection to occur?
What are four mechanisms of evolutionary change?
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