You are right, I didn't notice the rest of the sentence, but one thing that I know, is that when the verb 'descend' is used to say 'to be a blood relative of (an ancestor)' it usually changes its form to a passive verb, and is particularly used with 'from' (i.e. be descended from) (you can check this in "Concise Oxford English Dictionary"). Still wondering why 'to suggest' is right here!