The Genealogical Time Frame is considered by most to roughly be the last 500 years. It is often mentioned and used, especially in conjunction with genetic genealogy, to distinguish from anthropological studies of ancient populations. This time period corresponds to the beginning of written records of wider swaths of the population. Thus those people that genealogists can research, discover and add into their ancestral chart. Thus the focus of genealogical studies.
Autosomal testing in genetic genealogy often only works over the past 8 generations or 200 years, at most. This is much shorter than the genealogical time frame period. Thus other mechanisms are used to try and bridge this limitation. As earlier records tended to be more complete for the male head of household and heir (seemingly the only ones considered important enough to mention, record and tax), Y chromosome testing that works reliably from 1,000 years back to the present time is used. Key is finding a Patrilineal descendant living today of surnames that you wish to discover more about and have them yDNA AND Autosomal tested. Then looking for others related to that descendant with a common ancestor in the last 200 years and having them autosomal tested as well; hoping to match and verify the linkage. In this way, a genetic body of evidence can be built to help confirm possibly sparse records and generate a proof of a postulated family line. Using many Patrilineal line descendants to test yDNA allows one to link together many possible Patrilineal lines by validating the matching yDNA in a genealogical time frame. As the genetic genealogy field is still in its infancy to pre-teen years, the tools to support this type of collaborative effort are not quite available. But this is exactly what a surname project like this one is trying to support.
Autosomal testing in genetic genealogy often only works over the past 8 generations or 200 years, at most. This is much shorter than the genealogical time frame period. Thus other mechanisms are used to try and bridge this limitation. As earlier records tended to be more complete for the male head of household and heir (seemingly the only ones considered important enough to mention, record and tax), Y chromosome testing that works reliably from 1,000 years back to the present time is used. Key is finding a Patrilineal descendant living today of surnames that you wish to discover more about and have them yDNA AND Autosomal tested. Then looking for others related to that descendant with a common ancestor in the last 200 years and having them autosomal tested as well; hoping to match and verify the linkage. In this way, a genetic body of evidence can be built to help confirm possibly sparse records and generate a proof of a postulated family line. Using many Patrilineal line descendants to test yDNA allows one to link together many possible Patrilineal lines by validating the matching yDNA in a genealogical time frame. As the genetic genealogy field is still in its infancy to pre-teen years, the tools to support this type of collaborative effort are not quite available. But this is exactly what a surname project like this one is trying to support.