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I think that Americans with roots in the colonial era do have a number of interesting kinships that are very different from Europe, especially if they come from families that moved into the interior of the continent in the 19th century.
Consider this, we all know that we have 256 g-g-g-g-g-g grandparents (or at least places for them on the family tree). Go back a few more generations & we are talking about 4,096 or 8,192 or 16,384 ancestors. It is at about this level that many of us find our ancestors crossing the Atlantic.
Consider this: the population of all 13 colonies in the first half of the 18th century was less than 1 million & a lot less in the 17th century. Natural selection (aka, differential reproduction) has been working on the descendants of these immigrants. Some have huge numbers of descendants, numbering in the tens of millions. Others have only a few thousand descendants. I wouldn't be surprised if the 80/ 20 rule is at work here. Chances are, most Americans of colonial descent are really distant cousins to one another, because the odds of finding someone who doesn't share at least one of the 8,192 ancestral couples from the 1600s is really low. I think that many of the 5th to Distant Family Finder matches are people who share multiple lines of descent across the spectrum of each of their ancestries. Many of these lived in the 1600s & haven't been found yet by modern genealogy; thus, the all too often occurance of check a matches tree & saying, "Nope; nothing in common here."
In Europe, things are a lot different. Imagine having a lineage that has been bottled up for centuries in a modest sized town. You get back to that generation with 16,384 ancestors & realize that 90% of them live in a town today that has fewer than 5,000 people. Then you realize that 90% of the ancestors of the 16,384 have been in that same village for at least as long. Cousin intermarriage occurs frequently, in many cases to 1st, 2nd, or 3rd cousins. If most everyone in town is this closely related, the odds of randomly finding a spouse who is unrelated are remote. People are a lot more closely related to one another in a European village, in terms of shared genome, but only very distantly related to others outside of the village.
In America, people are a lot less closely related to their closest relatives (in terms of shared genome) than those in Europe, but are a lot more likely to find distant cousins scattered throughout the general population. If most people are distant cousins, odds are a person's spouse will turn out to be a distant cousin.
Of course, there are a minority of cases in America where the two spouses were first cousins. 4 of my 32 g-g-g-g grandparent couples in America were first cousin marriages. In each case, the first cousin marriage vastly amplifies the distance that autosomal DNA can detect. On a line of ancestry without a cousin marriage, the odds of finding a match from earlier than say 1800 is a lot less than if two of my g-g-g-g grandparents were first cousins who married one another. Matches shared through such a first cousin intermarriage many times have a MRCA as far back as the early 1700s or 1600s.
In terms of shared autosomal DNA, white Americans of colonial descent are a lot more likely to find black cousins who are more closely related to them than anyone in Europe. This trend is, of course, becoming more prevalent & obvious with each passing generation.
Timothy Peterman
Consider this, we all know that we have 256 g-g-g-g-g-g grandparents (or at least places for them on the family tree). Go back a few more generations & we are talking about 4,096 or 8,192 or 16,384 ancestors. It is at about this level that many of us find our ancestors crossing the Atlantic.
Consider this: the population of all 13 colonies in the first half of the 18th century was less than 1 million & a lot less in the 17th century. Natural selection (aka, differential reproduction) has been working on the descendants of these immigrants. Some have huge numbers of descendants, numbering in the tens of millions. Others have only a few thousand descendants. I wouldn't be surprised if the 80/ 20 rule is at work here. Chances are, most Americans of colonial descent are really distant cousins to one another, because the odds of finding someone who doesn't share at least one of the 8,192 ancestral couples from the 1600s is really low. I think that many of the 5th to Distant Family Finder matches are people who share multiple lines of descent across the spectrum of each of their ancestries. Many of these lived in the 1600s & haven't been found yet by modern genealogy; thus, the all too often occurance of check a matches tree & saying, "Nope; nothing in common here."
In Europe, things are a lot different. Imagine having a lineage that has been bottled up for centuries in a modest sized town. You get back to that generation with 16,384 ancestors & realize that 90% of them live in a town today that has fewer than 5,000 people. Then you realize that 90% of the ancestors of the 16,384 have been in that same village for at least as long. Cousin intermarriage occurs frequently, in many cases to 1st, 2nd, or 3rd cousins. If most everyone in town is this closely related, the odds of randomly finding a spouse who is unrelated are remote. People are a lot more closely related to one another in a European village, in terms of shared genome, but only very distantly related to others outside of the village.
In America, people are a lot less closely related to their closest relatives (in terms of shared genome) than those in Europe, but are a lot more likely to find distant cousins scattered throughout the general population. If most people are distant cousins, odds are a person's spouse will turn out to be a distant cousin.
Of course, there are a minority of cases in America where the two spouses were first cousins. 4 of my 32 g-g-g-g grandparent couples in America were first cousin marriages. In each case, the first cousin marriage vastly amplifies the distance that autosomal DNA can detect. On a line of ancestry without a cousin marriage, the odds of finding a match from earlier than say 1800 is a lot less than if two of my g-g-g-g grandparents were first cousins who married one another. Matches shared through such a first cousin intermarriage many times have a MRCA as far back as the early 1700s or 1600s.
In terms of shared autosomal DNA, white Americans of colonial descent are a lot more likely to find black cousins who are more closely related to them than anyone in Europe. This trend is, of course, becoming more prevalent & obvious with each passing generation.
Timothy Peterman
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