The last common ancestors of all people with longstanding European ancestries lived only 600 years ago – meaning that if we could draw a perfect complete family tree for all Europeans, at least one branch on each tree would pass through a single person who lived around 1400 CE. This person would appear on all our family trees, as would all of their ancestors. The fact that multiple positions are occupied by the same people indicates that the notion of a tree is again not the most accurate metaphor for describing genealogy: trees only ever branch, but family trees contain loops. Your own
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