April 23, 2013
Reconstructing Europe’s Ancient History With DNA
Lee Rannals for redOrbit.com — Your Universe Online
Researchers wrote in the journal Nature Communications they have reconstructed the genetic history of modern Europe.The team was composed of scientists from the University of Adelaide's Australian Centre for Ancient DNA (ACAD), the University of Mainz in Germany and the National Geographic Society´s Genographic Project. They used DNA extracted from bone and teeth samples from prehistoric human skeletons to sequence a group of maternal genetic lineages that are now carried by up to 45 percent of Europeans.
"This is the first high-resolution genetic record of these lineages through time, and it is fascinating that we can directly observe both human DNA evolving in 'real-time', and the dramatic population changes that have taken place in Europe," says joint lead author Dr. Wolfgang Haak of ACAD. "We can follow over 4000 years of prehistory, from the earliest farmers through the early Bronze Age to modern times."
Joint lead author Dr. Paul Brotherton, formerly at ACAD and now at the University of Huddersfield, said the record of this group, known as Halpogroup H, shows the first farmers in Central Europe came from a wholesale cultural and genetic input through migration. This group started in Turkey and the Near East, where farming originated and arrived in Germany 7,500 years ago.
"What is intriguing is that the genetic markers of this first pan-European culture, which was clearly very successful, were then suddenly replaced around 4500 years ago, and we don't know why," said ACAD Director Professor Alan Cooper. "Something major happened, and the hunt is now on to find out what that was."
Researchers developed new advances in molecular biology to sequence mitochondrial genomes from the skeletons, creating the first ancient population study using a large number mitochondrial genomes.
"We have established that the genetic foundations for modern Europe were only established in the Mid-Neolithic, after this major genetic transition around 4000 years ago," says Dr. Haak. "This genetic diversity was then modified further by a series of incoming and expanding cultures from Iberia and Eastern Europe through the Late Neolithic."
Brotherton said the expansion of the Bell Beaker culture is a key event, emerging in Iberia about 2800 BC and arriving in Germany several centuries later.
"This is a very interesting group as they have been linked to the expansion of Celtic languages along the Atlantic coast and into central Europe," Dr. Brotherton added.
Cooper says these sequences help to provide a unique opportunity for scientists to investigate the demographic history of Europe.
"We cannot only estimate population sizes but also accurately determine the evolutionary rate of the sequences, providing a far more accurate timescale of significant events in recent human evolution," said Cooper.
A study reported last year in the journal Trends in Genetics found many cultural, climatic and demographic events shaped genetic variation among modern-day European populations. The team from this study used newer analytical techniques to help shape the views about the evolutionary history of humans in Europe.