Sciency Thoughts: Domestication

Showing posts with label Domestication. Show all posts

Monday, 31 July 2023

Cattle in the rock art of Wadi Bajdha, Saudi Arabia.

Saudi Arabia covers an area of about 2 million km² with rock art known from every area of the country. A comprehensive survey of the rock art of Saudi Arabia begun in 1981 took over 15 years to complete, and recorded over 2000 sites with pre-Arabic and early Arabic inscriptions, as well as thousands of petroglyphs (images made by inscribing into a rock surface).

In a paper published in the Journal of Historical Archaeology and Anthropological Sciences on 3 July 2023, Majeed Khan and Faisal Al-Jabrin of the Antiquities Sector of the Saudi Ministry of Culture, describe a newly discovered rock art site at Wadi Bajdha in the Tabuk Region of Saudi Arabia, and discuss the implications of the images discovered there.

The art is located in a deep valley surrounded by mountains to the northwest of the city of Tabuk, where water collected during the rainy season. The site has historically been visited seasonally by Bedouin herders, and may have, at times, hosted permanent settlements.

The rock art is located on a vertical rock face on the side of a hill, which appears to contain images from different periods. The oldest figures on this panel appear to be a group of Cattle with short horns and flat humps. These Cows appear to be different from both the long-horned Oxen depicted at the Neolithic sites of Jubbah and Shuwaymis, and the high-humped Indian Zebu-like Cattle depicted in the Najran area of southern Saudi Arabia. Khan and Al-Jabrin suggest that this art represents the second phase of Cattle domestication in Saudi Arabia, following the Neolithic long-horned Oxen phase.

The rock art gallery at Wadi Bajdha in the Tabuk Region, in north of Saudi Arabia. Khan & Al-Jabrin (2023).

The rock art of Saudi Arabia is highly diverse, and appears to have been produced in a range of contexts with different purposes and meanings. Neolithic images appear to show Oxen as both Animals hunted as prey, and as sacred or possibly Divine Animals. Chalcolithic images have been interpreted to show Oxen as mythical creatures, deities, and sacrificial Animals. With this in mind, Khan and Al-Jabrin are careful to compare the Wadi Bajdha rock art to rock art from other locations, before drawing any conclusions about its meaning.

An open air temple, where Cows are depicted with idoliform images possibly deities or gods, located in Wadi Damm northwest of Tabuk. Believed to be evidence of Cow worship in Arabia. Khan & Al-Jabrin (2023).

Archaeological evidence and rock art depictions both suggest that Wild Cattle, Bos primigenius, were present in Arabia as both wild and domestic Animals during the Neolithic. At sites such as Shuwaymis, Jubbah, Hanakiya, large numbers of Oxen are depicted, with flat backs and exaggerated horns. These resemble European Wild Cattle, Bos primigenius, an Animal not known after the Neolithic climate shift, which occurred about 7900 years ago in northern Arabia, and led to a shift from a cool, humid climate to a hot, arid one.

Long-horned flat-back Oxen from the Neolithic Shuwaymis site in the north of Saudi Arabia. Evidence of the presence of Wild Oxen in Arabia. Khan & Al-Jabrin (2023).

Petroglyphs of Cattle in Saudi Arabia represent at least three separate climatic phases, which each phase associated with images of different sizes, styles, and execution techniques, which has enabled the development of a chronology for such art, which links Animal type to climate shifts.

Earliest known image of Long-horned Cow, Bos primigenius, from Saudi Arabia dated to about 9000 BC. This image located at the Neolithic Jubbah, site in the north of the country. Superimposed on the Cow is a Camel figure of much later period. There is a difference of several thousand years between the two Animals; representing two climatic phases; cool and humid (Cow) and hot and dry conditions (Camel). Khan & Al-Jabrin (2023).

The style of the rock petroglyphs at Wadi Bajdha suggests that the art dates from the Chalcolithic Period, about 3500 BC. At this time people in the area had domesticated Cows and Goats, and engaged in small-scale hunting along with the hunting of Ibex. Camels did not appear in Arabia until the Bronze Age (along with Date Palms), and are absent from the Wadi Bajdha art.

A pregnant Cow. A small baby can be seen inside the mother Cow, a firm indication of a domesticated Cow. Domesticated small horned and flat back Cattle are found on several sites in northern and southern Arabia representing the middle phase of Chalcolithic domesticated Cows, around 3500 BC. Khan & Al-Jabrin (2023).

The left corner of the Wadi Bajdha panel depicts a number of large, Chalcolithic-style Cows, as well as several Ibex, and some Horse riders with lances. These appear to have been made by artists from different periods, who took care not to overlap the art, as well as some tribal symbols. Battles between riders armed with lances was common among Bedouin tribes into the recent past.

The third phase in the art gallery represented by Camel and pre-Arabic Thamudic inscriptions in addition to Horse riders with long lances in fighting attitude drawn by the people representing the last phase of rock art in this gallery. Khan & Al-Jabrin (2023).

The Wadi Bajdha art shows apparently domesticated Cattle, including a pregnant female with a baby inside, but no images of Camels, suggesting that this art is Chalcolithic in origin. The site is likely to have has good living conditions during this interval, supporting a permanent or semi-permanent population, who presumably left as the climate continued to get hotter and drier. Many other rock art sites in Saudi Arabia show similar combinations of Human and Animal figures, and appear to have been abandoned after short periods of occupation. This suggests that the population of Saudi Arabia has been largely nomadic for much of its history, inhabited by groups who moved regularly depending on the availability of water.

Saturday, 27 August 2016

Identifying the clothes of Ötzi the Iceman.

In 1991 two German hikers in the Ötztal Alps of the South Tyrol Region of Italy discovered a Human body partially exposed on the surface of a glacier. Careful examination of this body revealed it to be, not as originally thought a modern corpse, but the mummified remains of a 5300-year-old Chalcolithic (Copper Age) hunter, the oldest mummified remains ever discovered in Europe. The mummy, dubbed Ötzi the Iceman, became an overnight sensation, and has been the subject of numerous studies, due to the unique insight he offers into the lives of Chalcolithic Europeans.

Ötzi the Iceman as he was originally discovered. South Tyrol Museum of Archaeology.

As well as the body of Ötzi himself, the site yielded numerous items of personal effects, the clothes worn, and goods carried by, Ötzi at the time of his death. One area that has interested scientists since the time of the discovery has been the animals from which the Ötzi's cloths were made. A variety of approaches have been tried in trying to solve this puzzle, including DNA analysis, proteomic analyses (analyses of proteins) and study of the microstructure of the leather, but all have been thwarted by the advanced state of decomposition of the material.

In a paper published in the journal Scientific Reports on 18 August 2016, Niall O’Sullivan of the Institute for Mummies and the Iceman and the School of Archaeology and Earth Institute at University College Dublin, Matthew Teasdale and Valeria Mattiangeli of the Smurfit Institute of Genetics at the Trinity College, Dublin, Frank Maixner, also of the Institute for Mummies and the Iceman, Ron Pinhasi, also of the School of Archaeology and Earth Institute at University College Dublin, Daniel Bradley, also of the Smurfit Institute of Genetics at the University of Dublin, and Albert Zink, again of the Institute for Mummies and the Iceman, describe the results of a new study of the clothes of Ötzi the Iceman, which used mitochondrial DNA capture in oder to identify the animals from which the skins had come.

Mitochondrial DNA (mtDNA) is found in the mitochondria, organelles outside the cell nucleus. It is passed directly from mother to child without being sexually recombined each generation, enabling precise estimations of when individuals shared common ancestors, at least through the female line. Importantly, for the purposes of this study, mtDNA comes in much shorter packages than chromosomal DNA (it contains the code for making and operating the mitochondria only, not that for the whole body), and there is much more of it, since each mitochondria has its own DNA and there are typically 1000-2000 mitochondria in each cell, making it much more likely that enough mtDNA will survive for useful analysis.

O'Sullivan et al. were able to extract mtDNA from nine fragments of leather; four fragments of coat, one piece of loincloth, one piece of leggings, a shoelace, a piece of hat and a piece of leather from a quiver (arrow carrying device). Of these pieces thre fragments of the coat and the loincloth were found to be Sheepskin, the remaining piece of the coat and the leggings were Goatskin, the shoelace was Cow leather, the hat Bearskin and the quiver made from the skin of a Roe Deer.

The remains of Ötzi's coat, made from pieces of different skins. South Tyrol Museum of Archaeology.

At first sight the number of different skins, and the fact that these skins came from different animals, in the coat appears to suggest that clothing was assembled in a haphazard way from whatever materials were at hand. However making such a garment from different cuts of leather or cloth would not be unusual today. The fact that Ötzi's leggings were made out of Goatskin is illuminating, since a similar pair of leggings from a 4500-year-old Chalcolithic site in Switzerland were also made of Goatskin, suggesting that people were consistently using the same material to make the same garments, implying that the skins were being actively chosen for properties that made them suitable for certain garments.

Ötzi's leggings were made from several different peieces of skin, although mtDNA was obtained from only one fragment. South Tyrol Museum of Archaeology.

The Sheep and Goat skins used to make Ötzi's clothing, as well as the Cow leather of his shoelace all appear to have come from domestic animals, but the Deerskin of the quiver and Bearskin of the hat were almost certainly from wild animals, indicating that the Chalcolithic Alpine people were utilizing material from both sources. Interestingly an earlier study had previously revealed that Ötzi's stomach contents included meat from a Red Deer, as well as identifying several hairs found on Ötzi's body as also having come from Red Deer, indicating that he was able to utilize at least two Deer species.

Ötzi's quiver, made from the skin of a Roe Deer. South Tyrol Museum of Archaeology.

Saturday, 6 August 2016

Determining the diets of Late Mesolithic Humans at Cnoc Coig, Scotland.

In recent years isotopic and molecular analysis methods have transformed archaeology, enabling modern archaeologists to study the diets of and relationships between ancient peoples in a way that would have been unthinkable a few decades ago. One of the areas where these techniques have been very useful is the study of dietary and population changes during the transaction from Late Mesolithic hunter-gatherer societies to Early Neolithic farming societies across Europe. with genetic analyses able to track how movements of populations related to the introduction of new technologies and isotopic studies able to determine the diets of individuals for which only fragmentary remains are known.

While this has greatly improved our knowledge of this transition in mainland Europe, our understanding of the same period in the British Isles has been hampered by a severe lack of Human remains from Late Mesolithic sites. One area where some such remains have been found is the island of Oronsay in the Inner Hebrides, where disarticulated Human and animal remains have been recovered from a number of shell middens. Remains from one of these, Cnoc Coig, have been studied using modern molecular techniques, suggesting that these bones, a selection of 49 small fragments, principally from the hands and feet, come from at least six different individuals, that they ate a diet very rich in seafood (predicted to be an indicator of a hunter-gatherer lifestyle) rather than terrestrial livestock (predicted to be a indicator of farming), and that they date to slightly before 4000 BC (Neolithic pottery has been found at other sites on the West Coast of Scotland dating from about 4300 BC onwards).

In a paper published in the Journal of Archaeological Science on 2 August 2016, Sophy Charlton, Michelle Alexander, Matthew Collins and Nicky Milner of the Department of Archaeology at the University of York, Paul Mellars and Tamsin O'Connell of the Department of Archaeology and Anthropology at the University of Cambridge, Rhiannon Stevens of the Institute of Archaeology at University College London and Oliver Craig, also of the Department of Archaeology at the University of York, examine a series of small fragmentary remains from the Cnoc Coig site previously not considered identifiable, or only doubtfully listed as Human. The majority of these bone fragments did not come from the main shell midden, but rather were recovered from a trench dug close to the structure in 1975; all of these fragments having come from a single layer and therefore being presumed to have come from about the same time.

A total of 20 bone fragments were selected for use in the study, fifteen from the trench and five from the main midden. Charlton et al. attempted to extract collagen from these fragments, with nineteen yielding sufficient collagen for identification, of these two of the fragments were identified as having come from Seals (Pinnipedia sp.), and three from Wild Boar (Sus scrofa), an animal thought ton have been introduced to the Inner Hebrides from the mainland by Early Neolithic farmers.

Selection of bone fragments from the Cnoc Coig assemblage used within this research; highlighting the range of sizes, elements and preservation. From top, L-R, ZooMS IDs: Seal, Pig, remainder Human. Charlton et al. (2016).

An isotopic analysis of collagen from the bone fragments again suggested that the Humans had a diet largely of seafood, while the Seals were (as predicted) exclusively seafood eaters. The Boar, however, showed signs of a more varied diet, with two fragments having come from animals with a typical herbivorous diet, but the third showing signs of a more omnivorous diet with a high intake of marine foods. This is not a typical diet for Boar, and is highly supportive of the idea that this individual may have been a domestic animal being fed an atypical diet by its Human owners (a herbivorous diet for the other Boar does not rule out their being domestic animals, as Boar being kept at different locations by different people would be expected to have different diets.

It was possible to obtain carbon isotope dates from four of the specimens, two Human and two Boar fragments. The first Human fragment yielded a date of between 3991 and 3702 BC, while the second yielded a date of between 3944 BC and 3649 BC; the two Boar samples gave dates of 3982-3803 BC and 3977-3803 BC respectively, all consistent with the arrival of the earliest Neolithic Farmers on the West Coast of Scotland, and suggesting a mixed culture, with a population still largely dependent on hunted and gathered seafoods but starting to experiment with introduced domestic animals.

Wednesday, 23 May 2012

The origin of domestic dogs.

Dogs are our oldest domestic animal, and the only one which predates the adoption of agriculture. This has led to a great deal of study of the origin of domestic dogs over the years. Despite this we are still not entirely sure where dogs were first domesticated. We are now confident that domestic dogs are descended from a single species of wild canid, the Grey Wolf (Canis lupus), and that domestic dogs were widespread across Eurasia by 12 000 years ago. The earliest dogs in the archaeological record are debatable; archaeological sites in Europe and Siberia contain several purported examples of domestic dogs dating back as far as 33 000 years ago, but it is hard to be confident that these were truly domesticated dogs and not just wolves foraging around human occupation sites. The widespread human habit of ritually burying dogs is generally taken as evidence of domestication; the oldest known ritual burial of a dog is from a site in the Czech Republic thought to be at least 26 000 years old. Attempts to date the domestication of dogs using molecular clocks (measuring the rate of DNA mutation and comparing it to the nearest known relative) have been inconclusive. One such study suggested dogs may have divered from wolves 135 000 years ago, but this is widely disputed.

Fossil dog skull from the Czech Republic, thought to be at least 26 000 years old. A mammoth bone has been placed in the dog's mouth, suggesting a ritual burial. Mietje Germonpré/Discovery News.

In a paper published in the Proceedings of the National Academy of Sciences on 21 May 2012, a team of scientists led by Greger Larson of the Department of Archaeology at the University of Durham publish the results of a new genetic study of the domestication of dogs, combined with a review of our current understanding of the subject.

The team studied the genetics of six dog breeds widely considered to be ancient, the Akita, the Basenj, the Eurasier, the Finnish Spitz, the Saluki and the Shar-Pei, and also looked at data from studies of ten other breeds considered ancient; the Afghan Hound, the Alaskan Malamute, the American Eskimo, the Canaan, the Chow Chow, the Dingo, the New Guinea Singing Dog, the Samoyed, the Shiba Inu and the Siberian Husky.

Two of these dogs (the Eurasier and the American Eskimo are known to be twentieth century attempts to recreate ancient dogs; they should not show any notable differentiation from the general dog population. In the event the Eurasier did appear superficially to be ancient, but it is known to have been created by the hybridization of three ancient breeds, the Chow Chow, the Keeshond and the Samoyed, so this is not greatly surprising.

The (African) Basenji, the Dingo and the New Guinea Singing Dog all originate from outside the range of the Grey Wolf, so these are highly unlikely to be ancient breeds, though they should show signs of long isolation from other breeds. In the event the Basenji did appear to be distinctive from other dogs, appearing ancient, whereas the Dingo and the New Guinea Singing Dogs appeared to have interbred with European dogs extensively in the recent past.

The Basenji; a dog breed from Central Africa which has largely escaped hybridization with European dogs. Dog Family.

The Alaskan Marmalute is the only other breed from outside Eurasia, being descended from ancient sled dogs used by Alaskan nomads, but this dog is known to have nearly become extinct in the twentieth century and been recreated by breeders. Unsurprisingly these did not appear to be ancient in the study.

The dogs that did appear to be ancient in origin were the Chinese Shar-Pei, the Japanese Akita, the Basenj, the North African Saluki, the Afghan Hound, the Eurasier and the Finnish Spitz. The Finnish Spitz is known to have nearly gone extinct in the 1880s, but to have been saved by the efforts of a breeder, Hugo Roos, who travelled to remote villages seeking out individuals that had not been hybridized with other dogs. All the other breeds are non-European, and appear to have had some degree of protection from hybridization with European dogs. None of them are from areas associated with ancient dog burials.

Interestingly several other Asian breeds, including the Tibetan Terrier and the Pekingese, appeared to be nearly as ancient, judged by their genetic isolation from other breeds. Larson et al. suggest that this may help to explain these results. Until the mid-nineteenth century European dog-breeders were little concerned with bloodline purity, so dogs from different breeds often hybridized. During this period Europeans expanded aggressively around the world, taking their dogs with them. Dogs are most likely to have first been domesticated in Europe or an adjacent area of Western Asia, but dogs from these areas have never been reproductively isolated. Genetic studies looking for 'ancient' breeds of dog are in fact looking for breeds that have been reproductively isolated for long periods of time, but the breeds this have achieved that are not particularly likely to be any closer to the original domestic dogs than those which have repeatedly hybridized with other breeds.

The Pekingese; not thought to be an ancient breed, but reproductively isolated for a long time. Dog Breed Info Center.

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