Question

evan maclean and colleagues evaluated behavioral and genetic data from over 14,000 dogs, representing more than 100 breeds, and found that variations across breeds in certain behavioral traits, such as trainability (which can be seen when a dog demonstrates willingness to attend to its owner), could be attributed to genetic differences between those breeds. the team then reviewed previous studies to identify genes that are particularly likely to influence behavioral differences in dogs, identifying pde7b as one such gene. pde7b has also been linked to behavioral differences among foxes, suggesting that
14 mark for review
which choice most logically completes the text?
a some genes responsible for behavioral differences between dog breeds are not unique to dogs.
bpde7b probably did not occur in the common ancestor of foxes and dogs.
c behavioral differences between dog breeds are smaller than those between dogs and foxes.
d most foxes and dogs behave in similar ways with regard to trainability.

Explanation:

The text mentions that the gene PDE7B, which is linked to behavioral differences in dogs, has also been found in foxes, suggesting that some genes responsible for behavioral differences may not be unique to dogs.

Answer:

A. some genes responsible for behavioral differences between dog breeds are not unique to dogs.