In a message dated 02/07/2002 20:24:21 GMT Daylight Time,
[log in to unmask] writes:
> Having just trawled my local University library catalogue, I finnd that the
> full article is available free from;
Many thanks for this. I've done a brief summary for the Time Team website,
which may be of interest on here: The genetics and statistical methodology is
too complicated for me to summarise quickly, but a few points may be helpful
1. The towns covered in the sample are North Walsham, Fakenham, Bourne,
Southwell, Ashbourne, Abergele, and Llangefni (on Anglesey). Buccal swabs for
DNA testing were taken from 313 males in these towns.
2. DNA samples were also taken from 94 males in Friesland (northern
Netherlands) and 83 males in Norway.
3. "The Central English towns were genetically very similar, whereas the two
North Welsh towns differed significantly both from each other and from the
Central English towns. When we compared our data with an additional 177
samples collected in Friesland and Norway, we found that the Central English
and Frisian samples were statistically indistinguishable."
4. "The best explanation for our findings is that the Anglo-Saxon cultural
transition in Central England coincided with a mass immigration from the
continent. Such an event would simultaneously explain both the high Central
English-Frisian affinity and the low Central English-North Welsh affinity."
5. A mass migration need not have taken place if continuous in-migration took
place over a sufficiently long period. This is unlikely as the period
involved would be extremely long.
6. Any in-migration could have taken place prior to the Anglo-Saxon period
(as far back as 425 BC), but again this is unlikely as there is little
evidence for this in the archaeological or historical record.
7. "Although our models assume a single instantaneous migration event, we
would also expect a more gradual process lasting several generations but
still resulting in the same degree of admixture (a picture which may fit the
historical data better to produce very similar genetic patterns."
8. "We note, however, that our data do not allow us to distinguish an event
that simply added to the indigenous Central English male gene pool from one
where indigenous males were displaced elsewhere or one where indigenous males
were reduced in number."
9. "This study shows that the Welsh border was more of a genetic barrier to
Anglo-Saxon Y chromosome gene flow than the North Sea. Remarkably, we find
that the resultant genetic differentiation is still discernible in the
present day. These results indicate that a political boundary can be more
important than a geophysical one in population genetic structuring."
10. The authors do not deal with the question of how representative these
towns might be of any wider population.