EVOLUTION EXAM

Front

Which of the following is a factor in natural selection?

• Individuals of a species compete with one another to survive.
• All species are genetically diverse.
• Individuals within a population who are better able to adapt to changes leave more offspring.
• All of these

Back

All of these

Answer explanation

All options are factors in natural selection. Competition among individuals, genetic diversity, and adaptability leading to more offspring all contribute to the survival and evolution of species.

Front

The fossil record provides evidence that

Back

Older species gave rise to more recent species.

Answer explanation

The fossil record shows a progression of species over time, indicating that older species evolved into more-recent species, supporting the theory of evolution. This contradicts the other options, which are inaccurate.

Front

Individuals who are better able to cope with the challenges of their environment tend to

Back

Leave more offspring than those less suited to the environment.

Answer explanation

Individuals who cope well with environmental challenges are more likely to survive and reproduce, leading them to leave more offspring than those who are less suited, thus enhancing their population over time.

Front

Examples of natural selection: skin color, antibiotic resistance, colorful feathers in male birds. Which is NOT an example?

Back

Dog breeds

Answer explanation

Dog breeds are a result of artificial selection by humans, not natural selection. The other options, like skin color and antibiotic resistance, are examples of traits shaped by natural selection in response to environmental pressures.

Front

Starting in 1954, commercial fishers in the northwest Pacific were paid based on how dark the shells of the oysters they caught were. Darker oysters have a more delicious taste, while light-colored oysters have a bitter taste. The fishers began to throw light-colored oysters back into the water if they caught them. What effect did this change in fishing technique most likely have on the oyster population over the next 20 years?

Back

The average color of the oysters became darker.

Answer explanation

By discarding light-colored oysters, fishers reduced their numbers in the population. Over time, this selective pressure likely led to a decrease in lighter-colored oysters, resulting in an overall darker average color for the remaining oysters.

Front

Which of the following statements gives the most likely explanation for the presence of two very similar species of squirrels living on opposite sides of the Grand Canyon?

Back

Members of a single squirrel species were geographically separated by the formation of the canyon.

Answer explanation

The correct choice explains that the canyon geographically separated members of a single squirrel species, leading to the development of two similar species on either side. This aligns with the concept of allopatric speciation.

Front

Some willow trees alter the chemical composition of their leaves when attacked by caterpillars. Compared to normal leaves, the chemically altered leaves are less nutritious and more difficult for caterpillars to digest. What is a likely effect of this ability?

Back

Willow trees with this ability have a survival advantage over other willow trees.

Answer explanation

The ability to alter leaf composition makes leaves less nutritious and harder to digest for caterpillars, reducing caterpillar damage. This gives willow trees a survival advantage over others that cannot defend themselves as effectively.

Front

Structures that share a common ancestry or are similar because they are modified versions of structures from a common ancestor and contain the same basic bone structure are

Back

Homologous.

Answer explanation

Structures that share a common ancestry and have similar bone structures are termed homologous. This indicates they evolved from a common ancestor, making 'homologous' the correct choice.

Front

The process in which organisms with traits well-suited to an environment are more likely to survive and produce offspring is

Back

Natural selection.

Answer explanation

Natural selection is the process where organisms with advantageous traits are more likely to survive and reproduce, leading to the prevalence of those traits in future generations.

Front

Structures with no function that are remnants of an organism’s evolutionary past are:

Back

Vestigial.

Answer explanation

Structures that no longer serve a function and are remnants of evolutionary history are called vestigial. This term specifically refers to these non-functional traits, making 'Vestigial' the correct answer.