Aren't (blood) relatives usually defined as the people with whom you share ancesstors? IE, what does it mean to say that two critters are related, if it doesn't mean they have a common ancestor?
The scientific fact is that the tree deduced from the fossil record is the same as the tree deduced from comparing DNA.
True.
IE, what does it mean to say that two critters are related, if it doesn't mean they have a common ancestor?
Relationships might be a bad phrase. How about a chart of common characteristics?
The scientific fact is that the tree deduced from the fossil record is the same as the tree deduced from comparing DNA.
That assumes the accuracy of the fossil record, and the accuracy of our calibration of the tree.