Clan Donald carry an SNP, which is
L176.1. SNP's are mutations that we get from our deep
ancestors, they do not change their values.
The Norse DNA that Sykes makes
reference to DOES not carry this SNP, therefore Clan
Donald did not get their ancestry from the Norse. Its
this simple. For your reference I am also attaching the
work that Sykes produced, as immature as it is.