If we assume that what Elin Eyjolfsdottir said below "and so on and so on" was true, we get this contradiction. After 10 generation you would have 2^10 = 1024 ancestors living at one time in your village of 100. After 20 generation you would have 2^20 = 1024 x 1024 ~ 1,000,000 ancestors living at one time in your village of 100. After 30 generation you would have 2^30 = 1024 x 1024 x 1024 ~ 1,000,000,000 ancestors living at one time in your village of 100. In Ireland at least, few people left their tuath and there were about 150 tuath, so people didn't travel far which they would have to do to get 1 billion distinct ancestors living in a village of 100, 750 to 1000 years ago. -----Original Message----- From: dna-r1b1c7-bounces@rootsweb.com [mailto:dna-r1b1c7-bounces@rootsweb.com] On Behalf Of David Maclennan Sent: Monday, May 26, 2014 1:14 PM To: dna-r1b1c7@rootsweb.com Subject: Re: [R-M222] Niall haplotype 'dubious' - Professor Mark Thomas When I was corresponding with Dr Elin Eyjolfsdottir (Celticist and Genealogist) about my Icelandic pedigrees, she had these words of wisdom which I will share with you: "As a reference point, in our genealogical records you will not find any Icelander who is not a descendant of Harald the Fair-haired, King of Norway in the 10th century, who is much later than Niall of the fifth/sixth century would have been. This is because as you know, with one set of parents, two sets of grandparents, four of great-grandparents, eight great-great-grandparents and so on and so on, you will find at least one person somewhere who is a descendant of Harald the Fair-haired. It is almost a genetic impossibility if you are of Irish descent and particularly of the Ulster region that you are not a descendant of 'a person' from Niall Noigiallach's era, but you can never be entirely sure who from². David On 2014-05-26, 12:08 PM, "Iain Kennedy" <ikennedy_msdn2@hotmail.com> wrote: ------------------------------- To unsubscribe from the list, please send an email to DNA-R1B1C7-request@rootsweb.com with the word 'unsubscribe' without the quotes in the subject and the body of the message