It is, of course, a fine thing to seek Scottish ancestry, and engaging with all aspects of Scottish history and culture is to be encouraged – but it must be done in the full knowledge that much of the mythology about clans, surnames, tartans and the like is just that.
Dr Bruce Durie.
'What is a Clan' is an excellent article by Dr Bruce Durie (previously Professor of Genealogy at Strathclyde University) published by Bletherskite http://www.bletherskite.net/2013/10/04/what-is-a-clan-by-dr-bruce-durie/#comment-21492 . It is concerned with - and shares much of my views about - the myths in Clan history / genealogy.
A flavour of the article is as follows -
3. Clans were territorial, accepting the authority of the dominant local grouping and looking to that chief as the patriarch, head, principal landowner, defender, military commander and dispenser of justice. Dependent families and individuals would often adopt the clan name as an indicator of affiliation and fealty to the Chief, so very often there is no genetic descent from a common ancestor or from the chiefly house – a vexed issue in the modern day of DNA test and genetic genealogy.
4.The first known divisions of Scotland (other than the “tribes” identified second-hand in Ptolemy’s Geography and Tacitus’s Agricola) were territorial, but with some reference to kinship
5. Actual kinship was not the issue so much as geographical co-locality. The original concept of heritage bound up with the clan was not surname. At this point, and well into the 13th Century, surnames (in the sense of passing unchanged from fathers to sons) were a rarity.
And a lot more - it is obvious how it fits much of the Gunn history on this website. I shall incorporate the key passages on to the relevant webpages...