Question 1

A major river changes course and divides a population of rabbits into two subpopulations. The two groups are reproductively isolated from each other and become subjected to different selective pressures in the two locations. A predator exists on one side of the river but not the other. Over time the two groups evolve enough that during a drought that temporarily allows the groups to once again intermingle, they can no longer reproduce with each other. What has happened in this example?

Accepted Answer

The answer of A major river changes course and divides...

Question 2

Green and blue coral snakes are found in even numbers on an isolated, small Pacific island. A hurricane hits the island and randomly kills the majority of the blue coral snakes. The remaining coral snakes repopulate the island, with green now being their predominant color. With regards to evolution, this change is considered an excellent example of ___________.

Accepted Answer

The scenario describes a bottleneck effect, where a random event (the hurricane) drastically reduces the population size and alters the gene pool. The surviving snakes have a different allele frequency, resulting in a change in their predominant color.

Question 3

Infographic 11.
-Refer to Infographic 11.3. A population of grasshopper mice preys upon a population of beetles. The population of beetles contains individuals with an adaptive trait of squirting a noxious fluid that repels the mice. Over time, the majority of beetles in the population will have the genes that provide for that trait. Use the infographic to describe what changes will need to occur in the grasshopper mouse population to counter what has happened in the beetle population. What is this situation an example of?

Accepted Answer

The answer of Infographic 11.
-Refer to Infographic 11.3. A population...

Question 4

________ species may benefit from activities that fragment habitat.

Accepted Answer

Edge species are those that thrive in the transitional area between two different habitats, such as the edge of a forest and a grassland. Activities that fragment habitat can create more of these transitional edge areas, providing more habitat for edge species to occupy.

Question 5

You have noticed in your greenhouse that your plants are covered by a pest, so you decide to apply a chemical pesticide. The first time you spray the pesticide, 90% of the pests are eliminated, but you have noticed that subsequent spraying of the pesticide has resulted in a smaller reduction of the pest population. What is happening in the pest population?

Accepted Answer

The answer of You have noticed in your greenhouse that...

Question 6

Which of the following is most likely the reason the bird species of Guam did not coevolve with the brown tree snake?

Accepted Answer

The brown tree snake preyed on the bird species too rapidly, which did not allow enough time for protective traits to be selected for and passed on to the next generation. This prevented coevolution from occurring between the bird species and the brown tree snake.

Question 7

Infographic 11.5.

-Refer to Infographic 11.5. The infographic shows a small, random, group of beetles being blown by storm winds from Island 1 to Island 2, which is a new area. This group is now physically isolated from the original population. How would you describe the population on Island 2 compared with the original population on Island 1? What is this concept called?

Accepted Answer

The answer of Infographic 11.5.

-Refer to Infographic 11.5. The infographic...

Question 8

A road that cuts through a forest is an example of __________.

Accepted Answer

A road that cuts through a forest creates habitat fragmentation, as the road creates a barrier that separates wildlife populations and disrupts the continuity of the forest ecosystem.

Question 9

The draining of wetlands for development is an example of __________.

Accepted Answer

The draining of wetlands for development leads to the destruction of a unique and critical habitat for many species, leading to a significant loss of biodiversity. This action can also negatively impact the ecosystem services provided by wetlands, such as flood control and water filtration.

Question 10

The loss of a trait is always a disadvantage to a population.

Accepted Answer

The loss of a trait can be neutral or even advantageous if the trait is no longer beneficial or if its absence provides a selective advantage in a changing environment.

Question 11

Which is likely not an example of coevolution?

Accepted Answer

A tree growing thicker and stronger to prevent breakage from hurricane force winds is an example of natural selection, but it is not an example of coevolution which involves the reciprocal evolutionary changes between two species that interact with each other. The other options involve interactions between two species that can lead to coevolution. Therefore, B is the best choice that is not an example of coevolution.

Question 12

If some members of a bird population had been able to escape Guam and colonize another island, which genetic concept would likely have happened?

Accepted Answer

The founder effect would likely have occurred because only a subset of the original population would have been able to colonize the new island, leading to a decrease in genetic diversity and potentially the establishment of different allele frequencies in the new population.

Question 13

Which event may lead two populations to undergo speciation?

Accepted Answer

All of these factors can contribute to speciation by causing genetic divergence between populations. Habitat fragmentation and isolation can physically separate populations, while changes in food availability and new predators can create different selective pressures.

Question 14

_______ happens when there is a decrease in the frequency of a particular trait due to random mating.

Accepted Answer

Genetic drift occurs when there is a decrease in the frequency of a particular trait due to random mating. This can result in the loss of genetic diversity over time. The founder effect and bottleneck effect are types of genetic drift, but they specifically refer to a small group of individuals becoming isolated from a larger population, or a sudden reduction in population size, respectively. Natural selection and extirpation are not related to changes in frequency due to random mating.

Question 15

The nation of Guam used to be home to 18 native avian species. By the 1980s, four species of birds had gone extinct and 10 others were in danger of extinction. What caused this to happen? What evidence was found to support this?

Accepted Answer

The answer of The nation of Guam used to be...

Question 16

When populations diverge, like that of the Arctic fox and the red fox, ______________.

Accepted Answer

When populations diverge to the point that they cannot interbreed and produce viable offspring, speciation may occur. This is likely the case with the Arctic fox and the red fox, as they inhabit different environments and have different physical and behavioral characteristics.

Question 17

Species are considered ______ when they face a high risk of extinction in the immediate future. Species are considered ________ when they are in danger of becoming _______ in the near future.

Accepted Answer

The answer of Species are considered ______ when they face...

Question 18

A genetic mutation that allows lions to better hunt their prey (gazelles) becomes prevalent in a population. In order to survive, a gazelle population must _________.

Accepted Answer

The gazelle population must coevolve to avoid the lions more effectively. This means that, over time, the gazelles that have traits that make them less vulnerable to lions (e.g. faster speed or better camouflage) will survive and pass on those advantageous traits to their offspring, eventually leading to a more predator-resistant gazelle population.

Question 19

Random events that play a role in evolution typically _________ genetic diversity.

Accepted Answer

The answer of Random events that play a role in...

Question 20

Several factors contribute to the endangerment of species including all of the following EXCEPT _________.

Accepted Answer

Diversification of genes does not contribute to the endangerment of species. Factors such as habitat destruction, anthropogenic climate change, overharvesting, and pollution all have negative impacts on species survival.

Quiz 11: Evolution- a Tropical Murder Mystery: Finding the Missing Birds of Guam