August 27, 2014
from
MessageToEagle Website
Something
very strange and unexplained happened with Europeans DNA 4,000-5,000
years ago.
For reasons totally
unknown, the genetic markers of this first pan-European culture,
were suddenly replaced around 4500 years ago. Scientists don't know
why...
Ancient DNA
recovered from a series of skeletons in central Germany up to 7500
years old has been used to reconstruct the first detailed
genetic history of modern Europe.
A study (Neolithic
Mitochondrial Haplogroup H Genomes and the Genetic Origins of
Europeans) conducted by an international team of
researchers at the University of Adelaide's Australian Centre for
Ancient DNA (ACAD), and their colleagues from the University of
Mainz, Germany and the National Geographic Society's Genographic
Project, reveals a dramatic series of events including major
migrations from both Western Europe and Eurasia, and signs of an
unexplained genetic turnover about 4000-5000 years ago.
The research was
performed at the University of Adelaide's Australian Centre for
Ancient DNA (ACAD).
Researchers 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% of Europeans.
People of the Beaker
culture
"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."
"The record of
this maternally inherited genetic group, called Haplogroup H,
shows that the first farmers in Central Europe resulted from a
wholesale cultural and genetic input via migration, beginning in
Turkey and the Near East where farming originated and arriving
in Germany around 7500 years ago," says joint lead author Dr
Paul Brotherton, formerly at ACAD and now at the University of
Huddersfield, UK.
Mid-Neolithic Europe
"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.
Something major
happened, and the hunt is now on to find out what that was,"
ACAD Director Professor Alan Cooper said.
"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.
What Caused The
Unexplained Change
In Europeans' DNA 4000-5000 Years Ago?
Scientists Say The Genetic Turnover Remains A Mystery
"This genetic
diversity was then modified further by a series of incoming and
expanding cultures from Iberia and Eastern Europe through the
Late Neolithic."
"The expansion
of the Bell Beaker culture (named after their pots) appears to
have been a key event, emerging in Iberia around 2800 BC and
arriving in Germany several centuries later," says Dr Brotherton.
"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."
"These well-dated ancient genetic sequences provide a unique
opportunity to investigate the demographic history of Europe,"
says Professor Cooper.
"We can not
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."
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