The mitochondrial DNA of the first Near Eastern farmers has been
sequenced for the first time. In the research, published in the journal
PLOS Genetics, experts analyzed samples from three sites located in the
birthplace of Neolithic agricultural practices: the Middle Euphrates
basin and the oasis of Damascus, located in today’s Syria and date at
about 8,000 BC.
Experts analyzed samples from three sites located in the birthplace of
Neolithic
agricultural practices
The paper is signed by Daniel Turbón and Alejandro Pérez Pérez, from the
Department of Animal Biology of the University of Barcelona (UB); Eva
Fernández, from Liverpool John Moores University; Cristina Gamba,
Eduardo Arroyo Pardo and Pedro Cuesta, from Complutense University of
Madrid; Eva Prats, from the Spanish National Research Council, and Josep
Anfruns and Miquel Molist, from the Universitat Autònoma de Barcelona
(UAB). The study is focused on the analysis of mitochondrial DNA —a type
of non-Mendelian maternally inherited DNA— from the first Neolithic
farmers, by means of samples obtained by the UAB research group which
were first processed by the UB research group.
The Neolithic: a profound revolution in human societies
Agricultural and husbandry practices originated around 12,000 years ago
in a region of the Near East known as the Fertile Crescent. This
phenomenon, known as “Neolithic”, meant a profound social, cultural and
economic transformation of human populations (agricultural production,
sedentary farming lifestyle, origin of the first cities and modern
societies, etc.).
Sites are located in today’s Syria and date at about 8,000 BCE.
Eva Fernández, first author of the article who got her PhD from UB,
explains that “the Neolithic Revolution rapidly expanded from these
territories into Europe, where the hunter-gatherer subsistence economy
—prevailing till then— was replaced by an agropastoral producing
system”. To know the nature of the diffusion of the Neolithic —in other
words, to know if it was a population migration process or a cultural
adoption— has been widely debated for the last fifty years. Different
research fields, for instance archaeology, physical anthropology,
linguistics and, more recently, human paleogenetics, have made
contributions to the discussion.
The unknown genetics of first Near Eastern farmers
The genetic composition of first Neolithic populations was one of the
mysteries of science till today, although some advances in European
Neolithic populations’ genetics were made during the last decade.
Professor Daniel Turbón points out that the results revealed by the
study published in PLOS Genetics “are the first ones regarding first
Near Eastern farmers; in other words, the genetic stock of original
Neolithic”.
Samples were obtained by the UAB research group and first processed by
the
UB research group
However, it is important to remember that other data have been published
about European first farmers, to be exact in Catalonia (by Cristina
Gamba et al., 2012), the Basque Country (by Hervella et al.) and Germany
(by Wolfgang Haak et al., 2010, and Brandt et al., 2013).
“Conclusions of previous studies —explains Turbón— are based on the
comparison with current Near East populations, as first agricultural
societies’ genetics have remained unknown until now”.
From the Near East to Europe
The study published in PLOS Genetics provides a new framework to
interpret the results of other studies about European Neolithic
populations, stress the authors. According to conclusions, genetic
affinities have been observed between the mitochondrial DNA of first
Neolithic populations and the DNA of first Catalan and German farmers.
The study is focused on the analysis of mitochondrial DNA —a type of
non-Mendelian maternally inherited DNA— from the first Neolithic farmers
This suggests that probably Neolithic expansion took place through
pioneer migrations of small groups of population. Moreover, the two main
migration routes ―Mediterranean and European― might have been
genetically linked.
“The most significant conclusion —highlights Eva Fernández— is that the
degree of genetic similarity between the populations of the Fertile
Crescent and the ones of Cyprus an Crete supports the hypothesis that
Neolithic spread in Europe took place through pioneer seafaring
colonization, not through a land-mediated expansion through Anatolia, as
it was thought until now”.
How did the Neolithic Revolution spread?
Other scientific studies had already provided signs of an alternative
scenario of Neolithic spread in Europe different from the one through
Anatolia. According to Turbón, “recent archaeological finds have proved
that the Neolithic arrived to Cyprus around 10,600 years ago, some years
after the first documentation of agricultural practices in the Near
East”.
The study provides a new framework to interpret the results of other
studies about
European Neolithic populations
Architecture and burial models found in Cyprus’ sites are similar to the
ones found in the Middle Euphrates basin, “that indicates a direct
colonization of these territories”, highlights the author. “Besides,
spatial interpolation of radiocarbon dates from different Neolithic
sites in the Near East and Europe also suggests a first seafaring
expansion through Cyprus”, he concludes.
In order to support these conclusions, the scientific team aims at
analyzing a greater number of human Neolithic samples from other regions
of the Fertile Crescent, and at increasing the number of genetic
markers analyzed in the samples.
