SMALL SAMPLES IN ARCHAEOLOGY. It will have occurred to you that three skeletons constitute a very small statistical sample if you are trying to get information about the movements of populations thousands of years ago.
I posted here about the Iceman, who was found in mummified condition in the Alps. It has been estimated that he died some 5300 years ago (about 3000 B.C.). The post was about a new study which showed that DNA linked him to Sardinia. A co-author suggested two possible explanations: First, during the past [10,000] years some people with a genetic constitution similar to [the] Iceman’s colonized Sardinia. Second, “the Iceman’s parents may have have traveled to the mainland from Sardinia.”
There is a third possible explanation: The Iceman was a lone traveler (and in terms of movements of peoples, an outlier).
(Mary Jane points out that since there are still 19 descendants of the Iceman living in the area where he was found, as I reported in this post, there is some—but not conclusive—evidence that he was not a lone traveler just passing through.)