The test result for a man from the British Isles might read as follows.
“Your Y-DNA marker is N-M46. Your ancestors were established in south east Asia some 25 000 years ago. Around this time a mutation occurred in one of your forefathers and the M231 marker arose in his YDNA and was passed on to his descendants. The group then migrated into China when another genetic change occurred, the marker known as M46.
As the climate grew warmer towards the end of the last glaciation your ancestors migrated northwards and westwards across the Siberian tundra, sometime around 12 000 years ago. Interestingly, no individuals carrying the M46 marker have been found on the American continent. This indicates that the migration from China to Siberia likely took place after the movement of peoples from Asia to the American continent. This in turn suggests that the land bridge across the Bering Strait had gone by that time.
The M46 marker is common across Siberia, particularly in the western part around the Tamyr peninsula. These tribes survived the harsh Arctic conditions as reindeer herders. At some stage they migrated westwards into northern Russia and Scandinavia and form the ancestors to the Saami people. During this migration they will have encountered (and must have mated with) Germanic people who had moved north to settle in Norway and Sweden.
The M46 marker is very rare in the British Isles, but it does occur. It is likely that your M46 marker arrived in the British Isles sometime between 800 and 1200 AD when there were Viking settlements along the coast of Scotland, in the northern parts of England and In Ireland.“