Stephen Oppenheimer

Seanachai

Is there anybody here who can explain in simple terms the rebuttals to Stephen Oppenheimer's research on the genetics of Ireland and Britain?. There are claims that it's bad science such as the guy below.

"The idea of Paleolithic genetic continuity has been demolished recently, as I detail in Migrationism Strikes Back. Most of the mtDNA haplogroups, thought by scientists to have been in Europe since the Paleolithic, were absent when actual Paleolithic DNA was tested. Genetic continuity must be proven directly, and inferences from modern populations are suspect.


Oppenheimer bases his inferences on age calculations based on Y-chromosome STRs on modern populations, using an extreme evolutionary mutation rate that overestimates time depth by almost an order of magnitude, and leads to even more extreme time overestimates than the evoluationary rate that I criticized recently."

http://dienekes.blogspot.ie/2009/10/stephen-oppenheimers-bad-science.html

Ipso

It comes down to two things mainly; dating of R1b-M269 (the big Western Europe Y haplogroup) and STR variance (best to google that).
Originally M269 was thought to be about 15,000 years old which put it at around the time of the ice age
It was found in highest numbers in the Basque region and as that area was relatively ice free at that time the age and the high numbers were put together and the idea that the basque region as a "crucible" for R1b was born.
As more testing was done and aging estimates improved it was found R1b-m269 was younger (now thought to have arisen about 8,000 years ago).
The str variance was found to be higher in the near east which implied an origin somewhere between the Balkans and Northern Iran. Also the mutations found in Ireland (L21) are also found more in the UK and the Basques have mainly a different one (m153).
As males can have a lot of male offspring quickly like in gaelic Ireland, where all sons had some kind of titles it guves a sutuation where male lines can grow exponentially giving a skewed number.
Also he only used spmething like 10 str's and you can test up to 111 with commercial companies at present. This increase in detail also showed Basques fell into different cluster than Irish people.
R1b hasn't been found in ancient DNA beyond 5,000 years ago or so.
There is a good book called Ancestral Journeys by Jean Manco which will also give a better explanation.

dubhthach

So far majority of ancient-DNA retrieved from Neolithic males are showing up as Haplogroup G with some Haplogroup I. Whereas ancient-DNA from Mesolithic males in comparison is showing up as exclusively Haplogroup I. Of course as more ancient-DNA is retrieved the picture may change somewhat.

The earliest known Haplogroup R1b so far found dates from the Copper/Bronze age and is associated with the Bell Beaker archaelogical culture.

The level of branching discovered in all major haplogroups has increased exponentially over the last 10 years.

As a result it's obvious that R1b has a gradient going form East -> West, with oldest (more diverse) clades found in the East (Balkans, Anatolia, Central Asia), and least diverse in West. So much so that for example R1b-L21 -- which probably dates to Bronze age -- reaches a level of circa 70% in Irishmen.

The oldest known "Haplogroup R*" (ancestral to both R1(a/b) and R2) is from Siberia (Mal'ta) and dates to about 24,000 years ago. The boy who remains was found is connected also to ancestral population of "native americans" (who are made up of mix of East Asian population with that of the Mal'ta population).

Here's an expansion map of clades of R1b-M269 in post-neolithic period presented by Dr. Michael Hammer at the recent FamilytreeDNA conference.