|DEPARTMENT OF GENETICS - Prof Mark A. Jobling|
For full details, read our paper: King, T.E. and Jobling, M.A. (2009) Mol. Biol. Evol. 26, 1093-1102. Founders, drift and infidelity: the relationship between Y chromosome diversity and patrilineal surnames. Article available as Open Access.
The names we studied were:
Attenborough, Beckham, Bray, Butterfield, Chubb, Clare, Clemo, Dalgleish, Feakes, Feakins, Grewcock, Haythornthwaite, Herrick, Hey, Jefferson, Jeffreys, Jobling, Ketley, King, Lauder, Mallinson, Northam, Pitchford, Ravenscroft, R., Secker, Slingsby, Slinn, Smith, Starbuck, Stead, Stribling, Swindlehurst, Tiffany, Titchmarsh, Titmus, Wadsworth, Werrett, Widdowson, and Winstone. To see all the spelling variants (as well as the surnames included in the control group), please read the Supplementary Data associated with our paper.
We found that men with rare surnames - such as Grewcock, Wadsworth, Ketley and Ravenscroft - tend to share Y chromosomes that are very similar, suggesting a common ancestor within the past 700 years. However, men with frequent surnames, such as Smith, are no more likely to have a recent common ancestor than men chosen at random from the general population - they derive from a person's trade and would have been adopted many times by unrelated people.
One of the most familiar of the rarer names we studied was Attenborough. In a random sample of Attenboroughs - including spelling derivations such as Attenborrow - almost nine out of ten men share the same Y chromosome type.
We used 'networks' to represent the Y chromosome diversity within surnames. Many networks contain 'descent clusters' representing men who share common ancestry through their shared name. The diagram below shows an example of network and descent cluster within the name Stribling.
Our paper includes only a selection of the networks; to see all 40 networks, please refer to the Supplementary Data associated with our paper.
We estimated how old these 'descent clusters' were - on average, they are about 650 years old, which is consistent with the average age of surname establishment.
We also looked at whether the Y chromosome-surname link could provide information about historical rates of children born illegitimately. A figure of one in ten is often quoted, but our study shows that this is likely to be an exaggeration - the real figure is more likely to be less that one in twenty-five.
Overall, the Y diversity we see within surnames suggests that 'genetic drift' (random variation introduced by differences in the numbers of sons that men have) has a very strong influence. Over time such drift contributes to the extinction of some Y-chromosome haplotypes and the fluctuation in the frequency of surviving haplotypes within surnames. The more drift, the fewer founding Y-chromosome haplotypes of a surname are likely to have survived, and the more genetic diversity will have been lost from the surname group.
Comparing our findings with previously published information on Ireland reveals some surprising differences. Unlike common British surnames, common Irish surnames (such as Ryan) contain many closely related men. There seems to be more genetic drift in Ireland, and one explanation is the prevalence of patrilineal dynasties there in the past.
A descent cluster usually contains different spelling variants of a name, showing that spellings were formalised quite late.
For DNA volunteers: click on your surname (or spelling variant) in the list below to download a pdf file (viewable in Adobe Acrobat Reader) containing a network showing how your Y chromosome type fits into your surname group. For this you will need your 'S' number, which was supplied to you when we returned your individual results in 2004-5; each node in the networks is labelled with the 'S' numbers of participants. For some surnames, a member has volunteered to act as a coordinator to facilitate contact between DNA donors. Coordinator contact details are shown on the relevant pdf. If there is no coordinator for a surname, and you are interested in becoming one, please email us at email@example.com. Note that we will not ourselves reveal any donor information – this can only be done through mutual consent among donors, via the coordinator.
Last updated: 27th October, 2009
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