Hello. I have been tracking my DNA results and have found a group of 4 of us with the same sequence on chromosome 7. Two of us have good trees built out and the only logical connection seems to be with Medcalf/Metcalf in Maryland or North Carolina in the 1700s. I am just wondering if anyone else with known Metcalf lineage has had their DNA tested so we could cross-reference.
By the way, I take classes in DNA and the answer to your question is that it takes about 1,000 years for DNA to be completely muddied. So blood descendants of Charlemagne would have no remaining DNA connection to him. Or no more that they would to any other person of that same time and place.
For example this strand of DNA on chromosome 7 that we think leads us to this Metcalf family in the 1700s is about 30 million bases pairs long. Every generation this will get shorter until it is short enough not to be indicative of a match at all (less than 700,000 consecutive base pairs).
Thank you,
Rick