23andMe has determined that I "most likely had a fourth great-grandparent, fifth great-grandparent, sixth great-grandparent, or seventh great (or greater) grandparent who was 100% Yakut. This person was likely born between 1720 and 1810." That equals <0.1%, so I'm not sure about the accuracy.
How could a Yakut person born between 1720-1810 come to be an ancestor of someone nearly 100% European? Could the search for the Northwest Passage come into play, or would they have been more likely to immigrate west?
This is as much a science question as it is a history one, so I would suggest you check out our sister subreddit, /r/AskScience, as there is a lot of discussion in threads there about the accuracy of these tests, especially when it comes to various non-European groups. This thread might be a good start, but a search will likely turn up more.