ThruLines at AncestryDNA is a clue and can be helpful in sorting matches that have trees associated with them. Researchers should validate the connections that ThruLines shows in the trees it creates. This is true with any record. Just because ThruLines is partially associated with a DNA test does not mean that it is any more accurate than any other source. The fact that two DNA tests are a match is based upon science. The probable relationship between those two tests based on the amount of DNA they share is based upon biology and statistics.

There’s two main reasons that I am not taking ThruLines as any more than a DNA result sorting guide:

• it’s based on trees (perhaps documented or perhaps not) whose reliability I have not validated for myself;
• the algorithm behind ThruLines is one where I’m not aware of all the details.

I realize there’s a school of genealogical thought that says any online tree that makes a statement about an individual being researched should be used as a clue. I understand that it is possible that someone has a statement in an online tree that is correct and is either:

• based on some obscure document they have located;
• correct but with no backup source–really hard to “know” in this case.

I’ve always been hard-pressed to use an online tree as a source for a statement about something that took place in 1750 if that tree has no source for that statement.

And if I’m not aware of the algorithm used to put someone in a ThruLines tree should I use it as “evidence” of the connection.

ThruLines is like a crude, hastily compiled, and partial index to a series of records. We use it to pick low-hanging genealogical fruit but we know that it is no substitute for putting the ladder up in the tree and going after each piece by ourselves one at a time.