The autosomal DNA testing (like your AncestryDNA test) we have done alongside the Y-DNA testing in this study shows a high level of inter-relatedness between people with Manx ancestry. Of course this is what one might expect from our knowledge of Manx family history. Autosomal DNA testing will identify potential cousins (up to ca 6-7th cousin) with common ancestors in the last 2-300 years. If you have Manx ancestry then an autosomal DNA test will almost certainly flag up a couple of previously unknown genetic cousins also with Manx ancestry. Good luck