About 3 years ago I had my Y-DNA tested with GeneTree. I had no idea whether the results would be useful but it was something I wanted to have done.
The results duly arrived and revealed that my haplogroup was E1b1b1-M35, with a predicted cluster of M81 and M183. Initially this meant nothing to me but the internet is a great resource and I soon found out that I was descended on my paternal line from East Africa and, through migration, with the Maghreb area of North Africa. In fact, M183 is known as the Berber Marker because of its frequency among Berber tribesmen. Mind you, that was over 5,000 years ago! I also share my genes with Einstein, the Wright Brothers, Napolean Bonaparte, Carravagio and Pope Paul V, amongst others. Just goes to show what a diverse lot we are! But not much help in tracing my ancestors.
When it came to the crunch, could I find anyone who had the same or nearly the same genetic profile? As it happens I did find a chap in the USA who had very nearly the same profile - it only varied by one repeat on a single marker. This indicated that we were probably very closely related - possibly sharing a common ancestor about 6 or 7 generations back. This is well within the period of recorded history and we could both trace our paternal ancestry back to Germany in the early 18th Century.
But there the search has ended - for the present. We are reaching back to the time when Jews were starting to adopt surnames. My contact and I have different surnames and whilst this is not altogether surprising and may be easily explained it makes searching for a common ancestor that much more difficult. Further, whilst my contact does have a fairly certain location for his family in Germany, my family does not. We could of course just search the records at my contact's location but what records would we look for? There are no civil birth records from this period but there other civil records. However, we would need to identify what would be the most appropriate records to use and then cope with handwritten German script. Most sensibly we would employ a local researcher but for the time being there the matter rests.
One breakthrough would be to identify where in Germany my paternal ancestor comes from. If it is the same location as my contacts' ancestor then we would be able to make real progress. Much work on this has been undertaken by my cousins and the results of their labours are recorded on the family web site: Jacobs Tree
So, for the time being, this is one of my "brick walls" but I am confident that there will eventually be a breakthrough as more 18th Century UK records are unearthed.