Errors in writing, voluntary changes by the bearers, modifications for language reasons... There are many reasons why the surname Aneca may have undergone changes or modifications, and from those modifications, surnames similar to Aneca may have appeared, as we can see.
Discerning whether the surname Aneca or any of the surnames similar to Aneca came first is not always easy. There are many reasons that could have led to the surname Aneca being written or pronounced differently, giving rise to a new, different surname Aneca with a common root.