Question

apple maggots are a type of fly native to north america. prior to the introduction of the apple tree to north america, apple maggots fed from and laid their eggs on hawthorn trees. after apple trees were introduced, some apple maggots began feeding from and laying their eggs on apple trees. adult apple maggots will only mate on the type of tree on which they were born.
what is the most likely consequence of the introduction of apple trees to apple maggots?
a. populations of apple maggots that mate on different trees could become reproductively isolated and eventually speciate.
b. individual apple maggots will eventually learn to lay eggs on both hawthorn trees and apple trees.
c. apple maggots that are born on apple trees will be unable to reproduce and will eventually die out.
d. some apple maggots will undergo adaptive radiation to colonize many other types of trees besides the apple and hawthorn.

Explanation:

When apple trees were introduced, some apple maggots started using them. Since they mate on the type of tree they were born on (hawthorn or apple), populations that mate on different trees (apple vs hawthorn) would be reproductively isolated. Over time, this can lead to speciation as they adapt to their respective host trees and genetic differences accumulate.

• Option A is correct as reproductive isolation (due to mating on different trees) can lead to speciation.
• Option B is incorrect because it's about individual learning, but the key is population - level reproductive isolation.
• Option C is wrong as there's no indication apple - born maggots will die out; they are just adapting to their host.
• Option D is incorrect as there's no evidence of adaptive radiation to many other tree types from the given information.

Answer:

A. Populations of apple maggots that mate on different trees could become reproductively isolated and eventually speciate.