Finally, after having my male Y-chromosome DNA profile posted for two years or so on the Family Tree DNA website, I now have a perfect match with a male Johnston in New Zealand. Statistically, we have a 90+% chance that we have a common male ancestor within the last 300 years and 100% within 600 years. I'm by no means an expert on this, nor do I work for Family Tree DNA. I am just downright impressed with the potential power of this new tool in genealogical research. Now David Johnston and I have to do some old fashioned genealogical digging to prove (or disprove) the linkage. If anyone wants to email me privately on this subject I'll be glad to share what I know about it.