If you go to book and search you will find your answer
"<span> You would not be able to pull your forearm up toward your shoulder" is the best option from the list, but it should be noted that there would be other issues as well. </span>
Chromalevota
Is your answer
This varieation can be justified because since they had different variations they probably had different niches which led them to evolve differently,this will help because the two species will have no competition
I believe it's B. BRCA1 and BRCA2.
