The Two Squirrel Species Shown in the Figure Below Arose

question 16

Multiple Choice

The two squirrel species shown in the figure below arose from the same ancestor.The Kaibab squirrel lives on the north rim of the Grand Canyon and the Abert's squirrel lives on the south rim.Which is the MOST likely explanation for their speciation?

• A) The population of ancestral squirrel occupied only one of the rims of the Grand Canyon. As the population grew, some members of the population crossed the Grand Canyon to form a new population.
• B) The population of the ancestral squirrel was split by the formation of the Grand Canyon. Since the habitats were different on each rim, the populations evolved differently and became reproductively isolated.
• C) When the Grand Canyon formed, competition for food and shelter became fierce. The two species arose through sympatric speciation as some individuals gathered food on the north rim rather than on the south rim.
• D) The ancestral squirrel was actually a hybrid of two squirrel species. When the populations were separated and could no longer mate, the characteristics of the two species became more obvious.

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Definitions:

Schizophrenia

A complex, long-term medical disorder that affects a person's ability to think, feel, and behave clearly.

Commit Suicide

The act of intentionally causing one's own death, often resulting from despair or mental health conditions.

Re-hospitalized

The act of being admitted to the hospital again after a previous discharge, often due to relapse or complication.

Residual Symptoms

Symptoms associated with schizophrenia, such as unusual beliefs or strange perceptual experiences, that are present for at least six months.