[Campbell Biology P.526] The "WHAT IF?" section states that soapberry bug eggs from a popula... | Practice Question

The "WHAT IF?" section states that soapberry bug eggs from a population that fed on balloon vine fruits, when reared on golden rain tree fruits, developed adult beak lengths similar to their original population. What does this suggest about the variation in beak length?

  • A: Beak length in soapberry bugs is primarily a heritable trait, largely determined by genetics rather than direct environmental influence during development.
  • B: The type of fruit consumed during the larval stage significantly influences the final beak length of adult soapberry bugs.
  • C: This result indicates that soapberry bugs cannot adapt to new food sources.
  • D: The development of beak length is entirely plastic, allowing individuals to adjust their beak size based on the available food source.

Explanation

The "WHAT IF?" scenario demonstrates that even when reared on a different fruit type, the adult soapberry bugs developed beak lengths similar to their original population. This implies that beak length is a heritable trait, primarily encoded by genes, and not significantly altered by environmental factors like diet during an individual's development. This is crucial for natural selection to act upon, as only heritable traits can evolve.