Upon His Return to England,Darwin Realized That the Species He

question 30

Multiple Choice

Upon his return to England,Darwin realized that the species he had seen in the Galápagos Islands were distinctive to that locale.Which of the following statements best explains the uniqueness of the assemblage of species that Darwin observed?

• A) Very little genetic drift was occurring, because the island populations were relatively large.
• B) The islands were too remote for human occupancy; therefore, the habitat modification that humans introduce had not yet occurred.
• C) No DNA mutation was occurring among the various island species.
• D) Very little gene flow was occurring, because the islands were so distant from the mainland.

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Definitions:

Specificity

The ability of a test to correctly identify those without the disease or condition being tested for.

Positive Predictive Value

The probability that subjects with a positive screening test truly have the disease.

Prevalence

The total number of cases of a disease that exist in a particular population at a specific time.

False-Positive Diagnosis

An erroneous identification where a test incorrectly indicates the presence of a condition that is actually absent.