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original article: phys.org

By  Trinity College Dublin

10,000-year-old DNA pens the first tales of the earliest domesticated goats
Indentation of several goat hooves in a brick from the archaeological site of Ganj Dareh. Credit: The ‘Tracking Cultural and Environmental Change project’.

New research has revealed the genetic makeup of the earliest goat herds. The findings, assimilated from DNA taken from the remains of 32 goats that died some 10,000 years ago in the Zagros mountains, provide clues to how early agricultural practices shaped the evolution of these animals.

Archaeological evidence has previously pointed to the Zagros Mountains of western Iran as providing the earliest evidence of goat management by humans. Here at the site of Ganj Dareh, the bone remains indicate deliberate slaughtering of male goats once they were fully grown.

In contrast, female goats were allowed to reach older ages, meaning early goat-keepers maximized the number of breeding female animals, similar to herders in the area today.

The close relationship between these early herders and goats can be seen in the very foundations of the settlement, with several bricks bearing the imprint of cloven goat hooves. However, their goats resembled the wild bezoar, with a larger body size and scimitar horn shape.

The international collaboration of researchers behind the study included individuals from Trinity College Dublin, the Smithsonian Institution, the University of Copenhagen, the Centre national de la recherche scientifique (CNRS) and Muséum national d’Histoire naturelle (MNHN) of France, and the National Museum of Iran.

The landmark study has just been published in the international journal PNAS.

Dr. Kevin G Daly, research fellow in Trinity’s School of Genetics and Microbiology and first author of the paper, said: “Our study shows how archaeology and genetics can address highly important questions by building off ideas and results from both fields. Our genetic results point to the Zagros region as being a major source of ancestry of domestic goats and that herded, morphologically wild goats were genetically on the path to domestication by about 10,200 years ago.”

Links to modern goats

Genetic analyses enabled the researchers to determine that the ancient goats fell at the very base of the domestic goat lineage, suggesting that they were closely related to the animals first recruited during domestication.

A surprising find, however, was the discovery of a small number of goats of the 32 whose genomes appeared more like their wild relatives—the bezoar ibex. This strongly suggests these early goat herders continued to hunt goats from wild herds.

Dr. Daly added: “This first livestock keeping shaped the goats’ genomes. There were signs of reduced Y chromosome diversity—fewer males were allowed to breed, leading to an increased tendency of relatives mating. Surprisingly, the Zagros goat appeared to not have undergone a population bottleneck often associated with domestication and lacked strong signals of selection found in later domestic goats.”

Dan Bradley, professor of population genetics at Trinity, said: “Ancient DNA continues to allow us to plumb the depths of ancient prehistory and examine the origins of the world’s first livestock herds. Over 10,000 years ago, early animal farmers were practicing husbandry with a genetic legacy that continues today.”

10,000-year-old DNA pens the first tales of the earliest domesticated goats


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zagrosmountains

 

Original Article:

cbsnews.com

 

BERLIN – Scientists say a previously unknown group of Stone Age farmers may have introduced agriculture to South Asia, challenging earlier theories that attributed the spread of farming to a different population.

Previous research held that a single group of hunter-gatherers developed agriculture in the Middle East some 10,000 years ago and then migrated to Europe, Asia and Africa, where they gradually replaced or mixed with the local population.

But scientists who analyzed ancient human remains found in the Zagros mountains of present-day Iran say they belonged to a completely separate people who appear to have taken up farming around the same time as their cousins further west in Anatolia, now Turkey.

“There was this idea that there’d been one group of genius inventors who developed agriculture,” said Joachim Burger, one of the authors of the study published online Thursday in the journal Science. “Now we can see there were genetically diverse groups.”

Scientists from Europe, the United States and Iran who examined the DNA of 9,000 to 10,000-year-old bone fragments discovered in a cave near Eslamabad, 600 kilometers (370 miles) southwest of the Iranian capital of Tehran, found they belonged to a man with black hair, brown eyes and dark skin.

Intriguingly, the man’s diet included cereals, a sign that he had learned how to cultivate crops, said Fereidoun Biglari of National Museum of Iran, who was also involved in the study.

Along with three other ancient genomes from the Zagros mountains, researchers were able to piece together a picture of a population whose closest modern relatives can be found in Afghanistan and Pakistan, and among members of Iran’s Zoroastrian religious community, said Biglari.

The Zagros people had very different genes than modern Europeans or their crop-planting ancestors in western Anatolia and Greece, said Burger, an anthropologist and population geneticist at Johannes Gutenberg University in Mainz, Germany.

He said the study’s authors calculated that the two populations likely split at least 50,000 years ago, shortly after humans first ventured out of Africa.

Burger said even though the two ancient farming populations didn’t mix, it’s probable that they knew of – and even learned from – each other, given that the development of agriculture is highly complex and therefore unlikely to have spontaneously occurred twice around the same time.

“You have to build houses, clear forests, cultivate several plants and ensure a plentiful supply of water. You also have to domesticate several animals, be able to grind flour, bake bread,” said Burger. “This is a huge process that takes several thousand years.”

Burger said the findings could help shed light on important developments in human history that have been neglected due to researchers’ long habit of focusing on ancient migratory movements into Europe.

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20131108-125811.jpg

Topic: pottery and salt

In July, I joined the Ur Digitization Project. As a part of this project, I have been working on a condition assessment of the ceramics from Ur. In doing the condition assessment I am looking at, measuring, and evaluating the stability of every ceramic vessel in the Museum’s collection from Ur. So far I have examined over half of the ceramics, and found that the main issue is soluble salts. I know when we all hear salt we think table salt. This is not too far off as table salt, or sodium chloride, is a soluble salt. This just means that the salt is soluble in water and in many cases is also hygroscopic (a big word for “absorbs moisture from the air”). We have all seen how salt clumps in salt shakers and won’t shake out nicely when it’s humid. This happens because the salt is hygroscopic.

You are probably wondering “Why this is a problem for ceramics?” Archaeological ceramics can absorb salts through moisture in the burial environment, and once they are excavated and dry out, the salts crystallize. If they crystallize inside the pores of the ceramic they can cause damage. If the ceramic is then exposed to changing relative humidity, these salts can go through cycles of dissolution as they pull moisture from the air and re-crystallization when they dry out, causing even more damage over time.

The pot on the left shows spalling. This happens when the salts pop off circular patches of the surface. You can see a spalled area in the front with the white salt crystals in the middle. The pot on the right is delaminating. This is also caused by the crystallization of salts. In this case they crystallize in a single plane, pushing off thin layers of the ceramic.

To stabilize the salty pots from Ur, I have been working on setting up a desalination station. This involves setting up an area where the pots can be safely soaked. Because these salts are soluble, they can be removed by soaking the object in water. The images below walk through the process I have been using to stabilize objects like the ones shown above.

Because the surfaces of the ceramics are so unstable, these objects have to be consolidated first with a dilute adhesive that is not soluble in water (otherwise the consolidant would be removed during desalination along with the salts). I have been using Paraloid B-72™ in acetone that I apply drop-wise so that I can control where it goes and how much is applied.

After the pots are consolidated and the adhesive has fully dried (I usually wait a few days after consolidation to be sure), each object is weighed and placed in a known volume of deionized water. The pots are weighed and the water measured so that I can calculate when they are ready to come out of the water and compare the data from pot to pot.

I use a conductivity meter to record how much salt is being extracted from each object. Every time I take a reading, I note the date and time as well so that I can plot the data on a graph. The length of time each pot soaks depends on various factors (weight, volume of water, how salty it is), but to give you an idea, they can stay in the water for a week or more. Once each pot has been desalinated I pull it out of the water, rinse it off, and let it dry.

If the surface is unstable after the pot has dried, I do some final consolidation. Once the treatment is complete, I take the final treatment pictures and the pot goes back to its home in storage.

Original article:
penn museum
By TESSA DE ALARCON | Published: OCTOBER 31, 2013

Follow the above link for additional information and photos.

20131108-130838.jpg
The salt in this shaker has clumped because the salt is hygroscopic –

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