What is a common method to test whether plate variation is due to plasticity or genetic differences?

• A. Genome-wide association study in wild populations
• B. Crosses with different species
• C. Measuring plate color
• D. Reciprocal transplant or common garden experiment

Answer: (D)

This question is about distinguishing whether variation in a trait comes from genetics or from plastic responses to the environment. A common garden experiment is the classic way to test this: raise individuals from different populations in the same controlled environment. If the plate differences persist, that suggests genetic differences underlie the variation; if the differences fade, environmental factors are driving the variation.

Reciprocal transplant takes this a step further by swapping individuals between their native environments. If the plates shift to resemble the local population after the move, that indicates plasticity in response to the environment. If they stay the same as their origin, genetics are the main factor.

This approach directly separates environmental effects from genetic ones, which is why it’s the best method for testing whether plate variation is due to plasticity or genetic differences. Other methods might identify genetic associations or compare across species, but they don’t cleanly test environmental versus genetic contributions in the same way.