30 April 2010

Nature And The Demise of Empires

Research on ancient climate events and natural disasters can provide considerable motivation for otherwise mysterious events in ancient history and pre-history.

Two serious Middle Eastern droughts, one of which explains the fall of one of the earliest empires in written history, and a major change in the river system of South Asia that lends credence to some of the geography described in the Rig Veda, are among them.

The Two Big Ancient Droughts

According to Kaniewski, et al., Middle East coastal ecosystem response to middle-to-late Holocene abrupt climate changes (PNAS 2008), based on ancient vegetation traces found in a dig in northwest Syria, there were two doughts in ancient history. A more mild drought from 2200 to 1900 BCE, and a more severe drought from 1100 to 800 BCE.

The Drought The Killed The Akkadian Empire

The first drought coincides closely with the fall of the Akkadian empire (which was the Semitic language speaking immediate successor to the non-Semitic language speaking Sumerian empire, where writing was first invented). The drought hit its peak around 2050 BCE. The Akkadian empire (the first other than the Sumerian and Egyptian empires to be well documented in writing) came into being in 2334 BC and collapsed in 2083 BCE.

Historical and archaeological evidence supports this theory. According to Wikipedia:

Evidence from Tell Leilan in Northern Mesopotamia shows what may have happened. The site was abandoned soon after the city's massive walls were constructed, its temple rebuilt and its grain production reorganised. The debris, dust and sand that followed show no trace of human activity. Soil samples show fine wind-blown sand, no trace of earthworm activity, reduced rainfall and indications of a drier and windier climate. Evidence shows that skeleton-thin sheep and cattle died of drought, and up to 28,000 people abandoned the site, seeking wetter areas elsewhere. Tell Brak shrank in size by 75%. Trade collapsed. Nomadic herders such as the Amorites moved herds closer to reliable water suppliers, bringing them into conflict with farmers. This climate-induced collapse seems to have affected the whole of the Middle East, and to have coincided with the collapse of the Egyptian Old Kingdom.

This collapse of rain-fed agriculture in "the Upper Country" meant the loss to southern Mesopotamia of the agrarian subsidies which had kept the Akkadian Empire solvent. Water levels within the Tigris and Euphrates fell 1.5 metres beneath the level of 2600 BC, and although they stabilised for a time during the following Ur III period, rivalries between pastoralists and farmers increased. Attempts were undertaken to prevent the former from herding their flocks in agricultural lands, such as the building of a 180 km (112 mi) wall known as the "Repeller of the Amorites" between the Tigris and Euphrates under the neo-Sumerian ruler Shu-Sin. Such attempts led to increased political instability; meanwhile, severe depopulation occurred to re-establish demographic equilibrium with the less favorable climatic conditions.

Documents writen after the collapse in the post-Akkadian era described as a curse:

For the first time since cities were built and founded,
The great agricultural tracts produced no grain,
The inundated tracts produced no fish,
The irrigated orchards produced neither wine nor syrup,
The gathered clouds did not rain, the masgurum did not grow.
At that time, one shekel's worth of oil was only one-half quart,
One shekel's worth of grain was only one-half quart. . . .
These sold at such prices in the markets of all the cities!
He who slept on the roof, died on the roof,
He who slept in the house, had no burial,
People were flailing at themselves from hunger.

The Old Kingdom in Egypt (2686 BCE – 2181 BCE) collapsed around the same time, giving rise to the First Intermediate Period in which the Egyptian empire collapsed into two kingdoms, each with declining central authority after having been united in one, that ended around 2080 BCE.

This drought may be responsible for the prohibitions on pig eating that survive today in Jewish Kosher rules and Islamic dietary restrictions according to William J. Burroughs, "Climate Change in Prehistory: The End of the Age of Chaos," (2008).

Finally, this drought may have weakened the states in Anatolia, allowing the first Hittite city-state to establish itself there.

The Bronze Age Collapse Drought

The second drought (1100 to 800 BCE) coincides with the "dark ages" that followed the Bronze Age Collapse and was worst around 900 BCE. This collapse of Mycenaean civilization (the earliest Greek speaking civilization in Greece) and the Hittite Empire (the earliest Indo-European language speaking empire in modern day Turkey), and attacks by "Sea People" as far as Egypt around 1200 BCE. Another part of the Bronze Age collapse mentioned in the paper is the destruction of Ugarit and the collapse of the Ugarit kingdom at ca. 1190 to 1185 BCE.

Crop failures, earthquakes and a major volcanic explosion in the Aegean (Thera, sometimes associated with the Atlantis myth) preceded the Bronze Age collapse. The greater severity of the second drought, or dating inaccuracies, could explain why its political impact preceded its most intense period signifiantly.

The Demise of the Sarasvati River

The other event or series of events was in South Asia and concerns the Ghaggar-Hakra River which "is an intermittent river in India and Pakistan that flows only during the monsoon season." This river system is probably the same river system that is called the Sarasvati River frequently discussed in the Rig Veda, and was once much more vibrant, Vedic literature also describes its demise. The Harappan civilization also known as the Indus River Valley civilization, was actually far more concentrated in the Ghaggar-Hakra River system than the Indus River. "Over 600 sites of the Indus civilization on the Ghaggar-Hakra river and its tributaries. In contrast to this, only 90 to 96 Indus Valley sites have been discovered on the Indus and its tributaries (about 36 sites on the Indus river itself.)"

In other words, Harappan culture was much more closely tied to the Northwestern part of South Asia from which the Indo-Aryan vedic culture began its association than is commonly assumed based on those of the Harappan sites that are inhabitable today.

Around 2000 BCE-1900 BCE, Harappan settlements move upriver where the river still flows. The Sutlej river which now is a tributary of the Indus River (whose basin more or less defines modern Pakistan) used to be a tributary of the Ghaggar-Hakra River. The Yamuna River, which is now the largest tributary of the Ganges River (which runs through most of the Indo-European language speaking parts of North India), also flowed into the Ghaggar-Hakra River during Harappan times. The realignment may have been due to a major earthquake, or may have been mostly due to declining rainfalls paralleling the cause the collapse of the Akkadian Empire in Mesopotamia and the Old Kingdom in Egypt. Other evidence suggests that the river collapse (replaced with elaborate canals) may have happened much earlier (around 3800 BCE).

Of course, there could have been one decline in river flow due to an earthquake around 3800 BCE, which grew more severe around 2000-1900 BCE making the river system no longer viable. The fact that mature Harappan settlements remained inhabited until around 2000 BCE argues against the events of 3800 BCE completely drying up the Savasvati basin by themselves, if there are separate events.

The Significance Of The Decline Date

The date of the demise of the Sarasvati River is probably the most reliable physical evidence to date the Rig Veda's composition, and the exact chronology has considerable historical relevance.

The Indus River Valley civilization was one of the earliest homes to farming based on Near Eastern crops, securing them around the same time as the Egyptians, around 7000 BCE, and the more sophisticated Harappan civilization began to emerge around 3300 BCE, reached its peak from around 2600 BCE to 1900 BCE, and then declined after 1900 BCE.

An earlier date for the demise of the Sarasvati River suggests that the increasing sophistication of the Harappan civilization may have been a response to the necessity of finding a way to continuing to farm with less water, and identifies much of the content of the Rig Veda with the Harappans, rather than with Indo-European language speaking invaders from the Central Asian steppe to the North.

In this scenario, if there was an invasion by Central Asia, the Central Asians adopted wholesale much of the pre-existing Harappan myths and religion, rather than importing it to South Asia. The Hittite and Tocharian Indo-European languages in this scenario (which in turn would give rise to the later Centem languages in Europe) would be a pre-invasion of India dispersal stratum, while the Statem Indo-European languages (e.g. Greek, Persian and Hindi) would be post-invasion of India dispersal languages with the distinctive aspects of that wing of the Indo-European languages likely influenced by a Harappan language substrate.

Thus, the transition from a Harappan language to an Indo-European one, might resemble the relative continuity of the contemporaneous transition from the Sumerian language of the Mesopotamian empire to the Semitic language of the Akkadian empire. Indeed, if the invasion took place significantly before the collapse of Harappan society due to aridity, the climate change could still motivate Indo-European expansion movements.

A later date for the demise of the Sarasvati River suggests that its demise may have created a power vacuum which Central Asian steppe invaders filled. A demise of this culture as a result of dried up rivers explains why the Harappan sites do not show the signs of violent destruction seen in other collapsed civilizations. The dry river would have killed the civilization, and any subsequent invaders would have filled it after the fact.

In a late Sarasvati River demise scenario, the invasion looks more like the post-Akkadian restoration of Sumerian culture in Mesopotamia.

The Out of India Indo-European Language Theory

Mainstream linguistic theory overwhelmingly favors a Central Asian origin for the Indo-Europeans, but the notion of a diaspora created by the drying up of the Sarasvati River right around the time that the Indo-European expansion takes place and strong Vedic religious ties to this river motivate a closer look at the evidence.

The drying of the river could also explain characteristic shifts in the disposal of the dead, with a shift from burial to cremation and exposure motivated either by widespread death that made burial economically impractical, or by the spread of disease that made it no longer safe.

The domestication of horses occurred long before the widespread appearance of Indo-European languages, and the discovery of chariots, associated with Indo-European expansion, could have been acquired from Central Asia by the Harappans through trade networks with Central Asia known to exist in the mature Harappan period. Proto-Indo-European commonality of martime language favors a Harappan, who had a vibrant maritime culture, over a Central Asian site for the proto-Indo-Europeans.

In an Out of India theory of Indo-European languages, a late demise of the Sarasvati River would support the idea that this was the motive for Harappans who were the Vedic/Proto-Indo-European people to expand out of Northwest India in all directions, giving rise to a widespread diaspora ranging from the Myceneans of the Balkans and mainland Greece, to the Hittites, to the proto-Indo-Iranians, to the Tocharians in the Tarim Basin (now part of China to the North of Tibet), to the Indo-Aryans originally in the Indus River Valley. All of them would have been people's needing to find new homes after their own had dried up.

Notably, in the Out of India theory, the Harappans don't necessarily have to be the same people as the early farmers of the Indus River Valley from 7000 BC, although they could be and there isn't any strong archeological or historical record of a violent invasion.

Large urban civilizations emerged in Mesopotamia and Egypt at about the same time as the Harappan Civilization did and there could have been an influx of people from Middle East at that time. The Harappan period also coincides with the expansion of trade from immediately adjacent areas in Iran and Central Asia, to a long distance trade system that extended to "portions of Afghanistan, the coastal regions of Persia, northern and western India, and Mesopotamia."

Population Genetics in an Out of India Scenario

From a population genetics perspective, this scenario would assume that Y-DNA haplotypes R* and R1* emerge somewhere between Mesopotamia and Pakistan, that one branch ends up in Pakistan and becomes R2, and that R1a and R1b split in the Fertile Cresent with R1b becoming associated with the Mediterranean/Atlantic expansion of agriculture (probably in connection with the Corded Ware Civilization), perhaps out of the Levant, and R1b being associated with the expansion of agriculture from Mesopotamia to both the Balkans and from their to Central Europe (the Linear Pottery Culture), and to the Indus River Valley civilizatioon where it remains largely confined until the demise of Harappan civilizatioon (with or without Central Asian invaders).

Y-DNA type L shows a strong Harappan area concentration. This could have been an early Neolithic Indus River Valley impact, with sister clade T accounting for a similar wave of migration in the Nile Valley (it is concentrated in the Upper Nile where the first Egyptian state began) and has outgroups that fit Egyptian trade routes at its peak eras.

Y-DNA haplogroup J would emerge in the Near East and quickly be differentiated between J1 associated with herders, and J2 associated with farmers perhaps in the same wave of migration as R1a into Harappan populations, a wave that might have been an early farming wave (ca. 7000 BCE) or might have been a later urbanized civilization wave (ca. 2600 BCE). Alternately, R1a might be an early element of neolithic populations in what is now Pakistan, while J2 might have been an addition that took place around the time of Harappan civilization's expansion, possibly in association with metal working.

The similar Y-DNA haplotypes in Central Asia could have come from via the Balkans, the Caucuses or the Harappans, or all of the above. An Indo-Aryan expansion from Harappa and one from the Central Asian plain both look similar in ultimate genetic outcome.

A hypothesis of population continuity between the Harappans and the earliest Indo-Europeans has some virtues to it from population genetics perspective. The Y-DNA haplotypes R1a and to a greater extent J2 (combined with an absence of herding pastoral nomad associated haplotypes like G, J1, N, and the North African E subtype), are associated with farming as opposed to herding. Continuity of populations from the Harappans, a farming population with strong ties to the Near Eastern farming complex, makes sense. In contrast, in a Central Asian steppe population, one must basically assume that the proto-Indo-Europeans were farmers who transitioned to being herders upon arriving on the steppes.

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