When people are first starting out their genealogical work, many seem to be impressed by lineages. For example, lineages showing descent from royalty can be fun to get people interested. As an example, I have included this link to a register report showing a putative lineage of most Spring Grove residents from King Harald IV . As genealogists develop and realize how wishful thinking and guessing can create errors in genealogical research, they recognize the importance of good documentation. They also realize that we should first focus on ancestors within the last 200 years in order to build on solid ground. Further, they recognize that the amount of genetic material a person carries from his or her potentially hundreds of thousands of grandparents 20 generations ago, is very small or even nonexistent. This is not to say that we should ignore more distant ancestry. There are many lineages in the written record on various websites and these lineages can be useful for understanding history. Some of these connections are well sourced while others have questionable or nonexistent sources. Even well sourced lineages could be in error due to illegitimacies, secret adoptions, or errors in the documentation. For that reason, many people have come to doubt the veracity of any lineage going back or forward more than 8 or 9 generations. But now, using advanced genetic tests, we can test trees that contain information that may be speculative, in order to identify errors and event test for veracity. If, for example, we have the y-chromosome of any two males who claim male-line descent on a tree from a given ancestor, we can quickly falsify that genealogical claim if the y-chromosomes are of a different haplogroup. We can do the same thing with female-lines using mt-DNA from male or female cousins. Further, we can identify distances between cousins (or even between hair found in an old Bible and someone today) by using autosomal DNA testing. Despite all the advances in technology, we do encourage people to try to restrain themselves from adding ancestors back many, many generations until they have sourced their trees so that that they are confident they are building on solid ground.