No Saxon invasion?

[authun]

Guys,
although this is a fascinating topic it's in grave danger of a) being diverted from the Anglo-Saxon invasion of Britain (or not) to discussing how to read a scientific paper

I shall try to move onto subsequent and forthcoming studies.

Weale et al further note "this is an extremely high rate even by modern standards" and thus they consider a rate of 0.3% rather unlikely, not a real objection. To be sure, they "conclude that these striking patterns are best explained by a substantial migration of Anglo-Saxon Y chromosomes into Central England (contributing 50%–100% to the gene pool at that time) but not into North Wales". This is regarded by Halsall and many readers (me included) as a statement of proof

And it is why I say Halsall, and yourself apparantly, are wrong to read it that way. 'Best explantion' does not mean proof in my book. Weale does not "assert that genetics "can ‘prove’" and I ask you once again to show me where he does make that claim. What he writes is "We accept that our data do not prove conclusively that an Anglo-Saxon mass migration event took place."

The explanation about the 0.3% background migration rate in the following sentances is not there to offer a reductio ad absurdum proof. Nor could it be because we still have to question the accuracy of the models and the quality of the assumptions made in the models. It is simply there to offer an explanation as to why Weale thinks the results "are best explained by a substantial migration of Anglo-Saxon Y chromosomes into Central England".

If you want to see a 'best explanation' as proof, that's up to you. I on the otherhand take it at face value and read it without embelishment. I suggest we leave it there. We read it in different ways.

I'm not sure if you're familiar with the modelling and the probability distribution estimation methods used by Weale et al, I work with similar stuff, this also why I dared to approach this paper (because I'm no geneticist, and I have history and linguistics as hobby).

How could either of us be familiar with the model which was developed for the purpose of this study by Mike Weale? It was specially written for this study. He does say that readers can obtain a copy of it from him, but I have never asked for it.

But the likelihood estimations depend on their model. If their model is wrong, so are their results.

All the more reason for not making a claim that the results prove it. That would be rather rash with a new and untested model.

If geneticists would really care about reliable identifications, they'd work with experts in other fields to create better models.

They do work with experts. You'll see Heinrich Härke's name on the Weale study.

These being said, I don't think the questions around the Anglo-Saxon invasions were answered by DNA studies. They rather brought more noise, than clarifications.

Weale's study was just the second step in the process. It was followed by Capelli's study, 'A Y Chromosome Census of the British Isles', as opposed to Weale's study of central England. Although Capelli's study showed a good deal more heterogenity in Britain than Weale did in his area of study, Capelli found that the input of paternal lineages from North Germany/Denmark into the modern English population was 54.1%. This was followed by Mark Thomas' 'Evidence for an apartheid-like social structure in early Anglo-Saxon England' which looked at the question, 'how could a small number of anglo saxon settlers, by Härke's estimate 10% of the population, grow to be larger than the indigenous population? Again models were developed which showed, within plausible limits, this was achievable within 8 to 12 generations.

Again though, we are using models. Everyone accepts the limitations of models and the assumptions made within them. That's why nothing is offered as proof and everything stated is offered as an explantion.

The People of the British Isles project have just submitted their first scientific paper for publication which will be made available to the public when ready. Unlike the above studies which are for yDNA only, the PoBI studies include yDNA, mtDNA and autosomal markers. There will be a number of publications from this extensive dataset so time will tell whether they support or detract from Weale's and Capelli's studies. But, if their 2006 pilot study is anything to go by it will show a yDNA cline from a roughly 75% anglo saxon east to a 50% anglo saxon west of England. But, we will have to wait for the results and see the arguments.

best
authun