Wednesday, October 30, 2013

Ancient DNA Shows Separate Stages of Development




This is important. It is way more reasonable to expect a simple transfer of technology than to expect a transfer of genes. Yet that appears to be the case and we can presume that this took place by the male linages. It would be nice to resolve that with mitochondrial DNA.

What we do learn is that such transfer did come with significant movements of peoples. This does not mean displacement but mostly intermarriage as new skills arrived with their purveyors in high demand.

This also took place before horses changed the military and movement equation. Thus movement was surely by foot on a village to village basis. This also constrained mass movem ent which became a serious later feature in Germany.

Ancient DNA reveals multiple stages of settlement in Europe


Research conducted by the National Geographic Genographic Project, a multiyear global initiative that uses DNA to map the history of human migration, is helping unravel the timing and source of human settlement in Central Europe.

Ancient DNA recovered from a time series of skeletons in Germany spanning 4,000 years of prehistory has been used to reconstruct the first detailed genetic history of modern-day Europeans [Credit: Juraj Lipták]



New ancient-DNA research led by the National Geographic Society's Genographic Project, the Australian Centre for Ancient DNA (ACAD) and researchers from the University of Mainz in Germany and the State Heritage Museum in Halle (Germany) showed a pattern of genetic replacement taking place across several millennia in a region of central Europe. The genetic data reveal the complex dynamics that went into producing the present-day genetic patterns in Europe and show that the region that is now Germany saw at least four stages of significant migration and settlement, highlighted by marked shifts in the genetic composition of the populations in the region.


One of the great debates in archaeological research for the past century has been the degree to which cultures or people move. When you see a pronounced cultural shift in the archaeological record, for instance, is it because of a new people appearing on the scene, or is it simply the diffusion of a new culture?
This new Genographic study shows definitively that, for Germany over a four-millennia-long time span from 5500 B.C. to 1500 B.C., it was people who were on the move, carrying their genes with them.


"This is the largest and most detailed genetic time series of Europe yet created, allowing us to establish a complete genetic chronology," said joint lead author and Genographic Project scientist Dr. Wolfgang Haak of ACAD. "Focusing on this small but highly important geographic region meant we could generate a gapless record and directly observe genetic changes in 'real time' from 7,500 to 3,500 years ago, from the earliest farmers to the early Bronze Age."

Chronology and distribution of prehistoric cultures in the Mittelelbe-Saale region : Maps depict the geographic distribution of Neolithic and Early Bronze Age cultures in Mittelelbe-Saale across Europe or Central Germany in chronological order. Eponymous or characteristic ceramic vessels are shown for each culture and dates refer to the occurrence and duration in Mittelelbe-Saale [Credit: Science Mag: DOI:10.1126/science.1241844]

Genographic Project Director Spencer Wells said: "This is perhaps the most important study to date of genetic patterns in Europe during a critical period in the formation of modern Europe. Painstakingly collected data from well-dated archaeological remains spanning a period from the dawn of farming during the Neolithic period to the Bronze Age reveal successive waves of migration and population replacement genetic 'revolutions' that combined to create the genetic patterns we see today."


Representatives of the Genographic Project, which uses advanced, multi-locus DNA analyses to help answer fundamental questions about human origins, looked at the mitochondrial DNA control region sequences from remains of 364 people from different prehistoric time periods and cultures of Central Europe and performed a chronological genetic study that spanned more than 4,000 years.


The remains from each time period were associated with known archaeological cultures of that time. Likewise, each period's remains were interpreted as indicative of that region's genetic diversity at that time, thus constituting a distinct population from other time periods. Each population showed marked differences from the others from the same region.


A paper on the research, "Ancient DNA reveals key stages in the formation of Central European mitochondrial genetic diversity," has been published by the journal Science.



A pdf entitled 'Supplementary Materials for Ancient DNA Reveals Key Stages in the Formation of Central European Mitochondrial Genetic Diversity' can be downloaded here

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