Belinda, I'm aware that endogamy exists in the USA, but I'm somewhat puzzled by the assertion that endogamy is on the whole more of a factor in the US than in most of the rest of the world. Europeans and Africans have only been present in the territorial US for a few hundred years, and many Americans' European ancestors didn't even get here until after 1850. For instance, all of my immigrant ancestors arrived in the US between about 1850 and 1895. A huge wave of European immigrants came here later than that, in the early 20th century. So while I know that my Norwegian ancestors were endogamous, and that my Scottish and German ancestors probably were too, that was back in Europe, not in the US. Sure, the colonial population became endogamous, and some populations in the US have remained or become so, but I don't see how the American (or even just the Euro-American) population is overall unusually endogamous compared to the rest of the world. What am I missing here? Karla Huebner calypsospots AT gmail.com On Thu, Sep 28, 2017 at 6:34 PM, Belinda Dettmann < [email protected]> wrote: > It is important to realize that DNA testers with predominantly US ancestry > come from an endogamous background, compared with the rest of the world. > That is, there is a degree of inbreeding in the USA, compared with the rest > of the world. This may not be apparent to local researchers, as most of the > statistics are calculated from USA data, where endogamy has been ASSUMED to > be zero. It is small indeed when compared to Ashkenazi or French-Canadian > populations, but it is larger than in mixed populations generally. > One of the side-effects of this is that, although USA DNA testers get > relationships predicted at roughly the right level, outsiders who share > ancestral, but not modern, populations with USA testers, tend to get more > US cousins than they would expect, and these cousins are predicted to be > closer relatives than they really are. This occurs because the degrees of > relationship are calibrated from USA data, so that testers from other > areas, > or from mixed populations, get misleadingly close predictions. > This remark was prompted by Tim Janzen's remark earlier today that " My mom > fortunately doesn't come from an endogamous ancestral background, which is > helpful when working with her triangulated groups. Endogamy definitely > complicates things." > I have an enormous regard for Tim's knowledge and acumen when it comes to > DNA matters, but this statement needs qualification. > It can be regarded as correct in an American context. It is NOT > appropriate > for testers whose ancestors never lived in the USA, who but share older > populations with them, such as Australians, Britishers, Irish, Germans, > Poles, etc. > > > > ------------------------------- > To unsubscribe from the list, please send an email to > [email protected] with the word 'unsubscribe' without > the quotes in the subject and the body of the message >