Can you find a Mr. Killian cousin to Y-DNA test who is descended from your dad's great uncle John Adam Killian b. 1876 Germany? I guess if that cousin that you find is in your dad's generation, then he would be your dad's 2nd cousin. I know some of my late dad's 3rd cousins, so bet you know your living dad's 2nd cousins. My dad lived 1914-2005. I sure hope you can find one to test. We have tested my Killian from Steinbach an der Holzecke, Bavaria, Germany and we have tested 2 men descended from Johann Michael Kilian of Ettlingen, BW, Germany. Your Ludwigshafen Am Rhein, Germany would give us a triangle of tested KILIANs. Ettlingen & your Ludwigshafen are closer together than they are to my Steinbach an der Holzecke. Google maps shows that by road Ettlingen & your Ludwigshafen are 85.6 km apart (53.2 miles), while the distance between your Ludwigshafen Am Rhein & my Steinbach an der Holzecke are 163 km apart, which is almost twice the distance. Ettlingen & Steinbach an der Holzecke are even further apart i.e. 174 km. I wonder how much these sets of Kilians had spread by the early 1700s & how many sets of Killian are in Germany.
The Ettlingen KILIANs are at a genetic distance of 17 for a 37 marker haplotype from the mode of my KILIANs of Steinbach an der Holzecke where a genetic distance of 4 out of 37 is the maximum allowed within a set of KILIANs. That is more than 4 times the allowable distance. For 67-markers the genetic distance is 24 -- way beyond the limit for sharing an ancestor since the time of taking surnames i.e. perhaps 4 times a thousand years. So the Ettlingen KILIANs are no kin to my Steinbach KILIANs -- they are different sets of KILIANs -- unrelated men took the surname KILIAN when surnames were initially taken. Since your KILIANs are twice as close geographically to the Ettlingen KILIANs, maybe your KILIANs will match the Ettlingen KILIANs or maybe your KILIANs will be yet another set of KILIANs. Regardless, the answer is interesting & helpful to determining the geographical spread of sets of KILIANs & the number of sets.
As other sets of KILIANs test, we will know the geographical extent of each set & may locate the father of your John Killian b 1859. You need the DNA to be sure you have not latched onto a man from the wrong set of KILIANs in Germany when you find a prospective father for your John KILIAN b. 1859.
James W. Green-R-L48 III
285 Agnew Road
Winnsboro SC 29180-6975