[INDO-EUROPEAN LANGUAGES A new study has
discovered that horses were first domesticated by descendants of
hunter-gatherer groups in Kazakhstan who left little direct trace in the
ancestry of modern populations. The research sheds new light on the
long-standing “steppe theory” on the origin and movement of Indo-European
languages made possible by the domestication of the horse.]
The domestication of the horse was a
milestone in human history that allowed people, their languages, and their
ideas to move further and faster than before, leading both to widespread
farming and to horse-powered warfare.
Scholars from around the world have
collaborated on a new inter-disciplinary research project, which was published in the journal Science 9 May 2018. The researchers analysed ancient and modern
DNA samples from humans and compared the results - the 74 ancient whole-genome
sequences studied by the group were up to 11,000 years old and were from inner
Asia and Turkey.
Photo: Aljabakphoto, Wikimedia Commons, CC
BY-SA 4.0Much of the study builds on questions raised by scholars of
Indo-European studies at the Institute of Nordic Studies and Linguistics at University of Copenhagen. A number of conflicting theories have been presented
about who first domesticated the horse, with previous studies pointing to
people of the pastoralist Yamnaya culture, a dominant herding group who lived
in Eastern Europe and Western Asia.
“The successful spread of the Indo-European
languages across Eurasia has puzzled researchers for a century. It was thought
that speakers of this language family played a key role in the domestication of
the horse, and that this, in combination with the development of wheeled
vehicles, allowed them to spread across Eurasia from the Yamnaya culture.”
However, as this study shows, domesticated
horses were used by the Botai people already 5,500 years ago, and much further
East in Central Asia, completely independent of the Yamnaya pastoralists. A
further twist to the story is that the descendants of these Botai were later
pushed out from the central steppe by migrations coming from the west. Their
horses were replaced too, indicating that horses were domesticated separately
in other regions as well.
No
link between Botai and Yamnaya cultures
The study does not find a genetic link
between the people associated with the Yamnaya and Botai archaeological
cultures, which is critical to understanding the eastward movement of the
Yamnaya. Apparently, their eastward expansion bypassed the Botai completely,
moving 3000 kilometres across the steppe to the Altai Mountains in Central and
East Asia.
Professor Alan Outram from the Department of
Archaeology at the University of Exeter and one of the paper’s authors, states:
“We now know that the people who first
domesticated the horse in Central Asia were the descendants of ice age hunters,
who went on to become the earliest pastoralists in the region. Despite their
local innovations, these peoples were overrun and replaced by European steppe
pastoralists in the middle and later Bronze Age, and their horses were replaced
too.”
Languages
spread through exchanges between several cultures
The authors also demonstrate the oldest known
Indo-European language, Hittite, did not result from a massive population
migration from the Eurasian Steppe as previously claimed.
In contrast to a series of recent studies on
population movement in Europe during the Bronze Age, the new results from Asia
suggest that population and language spread across the region is better
understood by groups of people mixing together.
“In Anatolia, and parts of Central Asia,
which held densely settled complex urban societies, the history of language
spread and genetic ancestry is better described in terms of contact and
absorption than by simply a movement of population.”
He adds:
“The Indo-European languages are usually said
to emerge in Anatolia in the 2nd millennium BCE. However, we use evidence from
the palatial archives of the ancient city of Ebla in Syria to argue that
Indo-European was already spoken in modern-day Turkey in the 25th century BCE.
This means that the speakers of these language must have arrived there prior to
any Yamnaya expansions.”
The study also shows that the spread of the
Indo-Iranian languages to South Asia, with Hindi, Urdu and Persian as major
modern offshoots, cannot result from the Yamnaya expansions. Rather, the
Indo-Iranian languages spread with a later push of pastoralist groups from the
South Ural Mountains during the Middle to Late Bronze Age.
Prior to entering South Asia, these groups,
thought to have spoken an Indo-Iranian language, were impacted by groups with
an ancestry typical of more western Eurasian populations. This suggests that
the Indo-Iranian speakers did not split off from the Yamnaya population
directly, but were more closely related to the Indo-European speakers that
lived in Eastern Europe.
Unique
collaboration between the humanities and the natural sciences
In this study, geneticists, historians,
archaeologists and linguists find common ground - pointing to increased
interaction between the steppe and the Indus Valley during the Late Bronze Age
as the most plausible time of entry of Indo-European languages in South Asia.
Several authors of the paper had radically conflicting views before the final
interpretation was achieved.
Lead author on the article, Peter de Barros
Damgaard, who is a geneticist working at the University of Copenhagen comments:
"The project has been an extremely
enriching and exciting process. We were able to direct many very different
academic fields towards a single coherent approach. By asking the right
questions, and keeping limitations of the data in mind, contextualizing,
nuancing, and keeping dialogues open between scholars of radically different
backgrounds and approaches, we have carved out a path for a new field of
research. We have already seen too many papers come out in which models
produced by geneticists working on their own have been are accepted without
vital input from other fields, and, at the other extreme, seen archaeologists
opposing new studies built on archaeogenetic data, due to a lack of
transparency between the fields."
"Data on ancient DNA is astonishing for
its ability to provide a fine-grained image of early human mobility, but it
does stand on the shoulders of decades of work by scholars in other fields,
from the time of excavation of human skeletons to interpreting the cultural,
linguistic origins of the samples. This is how cold statistics are turned into
history."
Guus
Kroonen adds:
“The recent breakthrough in ancient genomics poses
challenges for archaeologists, linguists and historians because old hypotheses
on the spread of languages and cultures can now be tested against a whole new
line of evidence on prehistoric mobility. As a result, we now see that
geneticists are driven by key questions from the humanities, and that research
within the humanities is energized by the influx of new data from the sciences.
In the future, we hope to see more cross-disciplinary co-operations, such as
the one leading to this study.”
