Grazing animals drove domestication of grain crops

By: Thomas Schmitt Attorney on July 08, 2019 / comment : 0 Americas, Archaeology, Asia, North America, South Asia, Tibet

Many familiar grains today, like quinoa, amaranth, and the millets, hemp, and buckwheat, all have traits that indicate that they coevolved to be dispersed by large grazing mammals. During the Pleistocene, massive herds directed the ecology across much of the globe and caused evolutionary changes in plants. Studies of the ecology and growing habits of certain ancient crop relatives indicate that megafaunal herds were necessary for the dispersal of their seeds prior to human intervention. Understanding this process is providing scientists with insights into the early domestication of these plants.

Large grazing animals have a strong selective force on plants, certain plants have evolved traits to thrive on pastoral landscapes. Spengler and Mueller theorize that yak herding may have helped drive buckwheat domestication in the southern Himalaya. This lone yak in the Lhasa region of Tibet is a significant evolutionary force on the plant communities around where it grazes [Credit: Robert Spengler]

The domestication of small-seeded annuals involved an evolutionary switch from dispersal through animal ingestion to human dispersal. Those are the findings of a new study by Robert Spengler, director of the Paleoethnobotany Laboratories at the Max Planck Institute for the Science of Human History, and Natalie Mueller, a National Science Foundation fellow at Cornell University, published in Nature Plants.

Spengler and Mueller demonstrate, by looking at rangeland ecology and herd-animal herbivory patterns, that the progenitors of small-seeded crops evolved to be dispersed by megafaunal ruminants. Although today the wild varieties of these species grow in small, isolated patches, the researchers illustrate that heavy grazing of these plants by herd animals causes dense patches to form near rivers or other areas that the animals frequent.

In ancient times, these dense patches of plants could have easily been harvested, just like modern farmers' fields - explaining how and why ancient people might have focused on these specific plants. This study provides an answer for this long-standing mystery of plant domestication.

Small-seeded crops are products of another age

During the mid-Holocene (7,000-5,000 years ago), in ecologically rich river valleys and grasslands all around the world, people started to cultivate small plants for their seed or grain. Wheat, barley, and rice are some of the earliest plants to show signs of domestication and scientists have extensively studied the domestication process in these large-seeded cereal crops.

Cattle herding in the mountains of Central Asia leads to the formation of dense stands of plants that have specific  adaptive traits to heavy grazing. As Spengler and Mueller point out, these homogenous plant patches or fields  are often composed to the ancient relatives of modern grain crops [Credit: Robert Spengler]

Researchers know significantly less about the domestication of small-seeded grain crops, such as quinoa, amaranth, buckwheat, the millets, and several now-lost crops domesticated in North America. The wild ancestors of these crops have small seeds with indigestible shells or seed coats. Today, these wild plants exist in small fragmentary patches dispersed across huge areas - the fact that they do not grow in dense clusters, like the ancestors of wheat and rice, would seem to have made these crop ancestors unappealing targets for foragers. The small seed sizes and hard seed shells, combined with the lack of dense wild populations, led many researchers to argue that they must have been a famine food.

Foraging enough wild seeds from these varieties to grind into flour to bake a loaf of bread would take weeks, especially for rarer or endangered crop ancestors. So why did early foragers focus so heavily on these plants and eventually adopt them as crops?

Spengler and Mueller present a new model, suggesting that when humans first encountered these plants, they would have grown in dense stands created by grazing megafauna, making them easy to harvest. As humans began to cultivate these plants, they took on the functional role of seed dispersers, and eventually the plants evolved new traits to favor farming and lost the old traits that favored being spread by herd animals. The earliest traits of domestication, thinning or loss of indigestible seed protections, loss of dormancy, and increased seed size, can all be explained by to the loss of the ruminant dispersal process and concomitant human management of wild stands.

A novel model for the domestication of small-seeded grain crops

Spengler and Mueller have been interested in plant domestication since graduate school, when they studied under Dr. Gayle Fritz, one of the first scholars to recognize the importance of the American Midwest as a center of crop domestication. Despite decades of research into the nature of plant domestication in North America, no one recognized that the true key was the massive bison herds.

A bison trail through a dense wild field of little barley. This plant is one of the progenitors of a North American lost crop. Heavy bison grazing activity seems to result in dense fields of this plant in the wild, which would have been easy for early foragers to collect the seeds from [Credit: Natalie Mueller]

The plants that were domesticated, what Mueller calls the "Lost Crops," would have been dispersed by bison in large swaths, making them easy to collect by ancient people and perhaps encouraging these communities to actively plant them themselves. When Europeans exterminated the herds, the plants that relied on these animals to disperse their seeds began to diminish as well. Because the wild ancestors of these lost crops are rare today and the bison herds are effectively extinct, researchers have overlooked this important coevolutionary feature in the domestication process.

However, this process is not unique to the American Midwest and the researchers suggest that there may be links between buckwheat domestication and yak herding in the Himalaya and amaranth domestication and llama herding in the Andes. The authors have identified parallel patterns in rangeland ecology studies, noting that heavy herd animal herbivory can homogenize vegetation communities. For example, heavy pastoralist grazing in the mountains of Central Asia causes many plants to die, but certain plants with adaptations for dispersal by animals thrive. The depositing of plant seeds in nutrient rich dung leads to ecological patches, often called hot spots, that foragers can easily target for seed collecting.

For over a century, scholars have debated why early foragers targeted small-seeded annuals as a major food source (eventually resulting in their domestication). Today, the progenitors of many of these crops have highly fragmentary populations and several are endangered or extinct. Likewise, without large dense homogenous stands of these plants in the wild, such as what exists in the wild for the progenitors of large-seeded cereal crops, it would have been impossible to harvest their seeds.

The conclusions that Spengler and Mueller draw help explain why people targeted these plants and were able to domesticate them. "Small-seeded annuals were domesticated in most areas of the world," explains Spengler. "So the ramifications of this study are global-scale. Scholars all over the world will need to grapple with these ideas if they want to pursue questions of domestication."

Spengler and Mueller are continuing their research into the role that grazing animals played in plant domestication. "Currently, we're studying the ecology of fields where modern herd animals graze as proxies to what the ecology would have looked like during the last Ice Age, when large herds of bison, mammoths, and wooly horses dictated what kinds of plants could grow across the American Midwest and Europe," explains Spengler. "We hope these observations will provide even greater insight into the process of domestication all over the world."

Source: Max Planck Institute for the Science of Human History [July 08, 2019]

Millet farmers adopted barley agriculture and permanently settled the Tibetan Plateau

By: Thomas Schmitt Attorney on July 02, 2019 / comment : 0 Anthropology, Asia, East Asia, Genetics, Tibet

The permanent human occupation on the Tibetan Plateau was facilitated by the introduction of cold-tolerant barley around 3600 years before present (BP), however, how barley agriculture spread onto the Tibetan Plateau remains unknown. Now by using both genetics and archaeological data, researchers from Kunming Institute of Zoology, CAS and Lanzhou University revealed that barley agriculture was mainly brought onto the plateau by the millet farmers from northern China. Moreover, the genetic contribution from millet farmers largely promoted the formation of the genetic landscape of the contemporary Tibetans. The work was reported on-line in the journal National Science Review.

Credit: Wen Tao/Xinhua/Corbis

According to archaeological evidence, before the permanent settlement of modern humans on the high altitudes of the plateau, the lower altitudes in the northeast Tibetan plateau were extensively occupied by millet farmers during 5200 to 3600 BP. Interestingly, towards the end of this period (since about 4000 BP), a coexistence of indigenous millet and exotic barley-wheat cultivation appeared in the area, making it probable that the millet farmers adopted barley agriculture and further migrated onto the high altitudes.

To test this possibility, the team analyzed large-scale mitochondrial DNA (mtDNA) data of current Tibetans (8277 samples) and the surrounding populations (58514 samples). Together with radiocarbon dating of cereal remains at different elevations, they identified two haplogroups (M9a1a1c1b1a and A11a1a), whose origins and migrations well matched the dispersal history of millet farming from northern China.

Moreover, these components were also found in ancient DNA of human samples excavated from Neolithic sites in which millet was the most important crop (e.g., Yangshao and Majiayao cultural sites), thus would represent the genetic legacy of millet farmers that is still retained in contemporary Tibetans.

Additionally, these millet farmers' genetic components are common in contemporary Tibetans (20.9%), and were probably even more common (40%-50%) in early Tibetans at about 3300 BP (when the barley farmers had already settled on the high altitudes).

Meanwhile, these components also contributed to the genetic differentiation between contemporary Tibetans and other East Asians. Therefore, the genetic contribution from Neolithic millet farmers played important roles in the formation of the genetic landscape of the current Tibetans.

These results demonstrate that substantial genetic components in Tibetans trace their ancestry back to the Neolithic millet farmers. The most probable explanation for this observation is that the millet farmers adopted and brought barley agriculture to the Tibetan Plateau and finally occupied the high altitudes permanently. This work thus provide deeper insights into the dispersal model of barley agriculture onto the Tibetan Plateau, as well as the origin and migration history of the Tibetans.

Source: Science China Press [July 02, 2019]

Earliest archaeological site on Qinghai-Tibet Plateau confirmed

By: Thomas Schmitt Attorney on June 17, 2019 / comment : 0 Archaeology, Asia, China, Early Humans, East Asia, Tibet

A karst cave in northwestern China has been confirmed as the earliest archaeological site ever discovered on the Qinghai-Tibet Plateau, Chinese researchers announced at a press conference over the weekend.

Ancient human mandible fossil identified as a Denisova (referred to as Xiahe people) discovered in the Baishiya cave in Xiahe County, Gansu Province [Credit: Xinhua News Agency/Li Jie]

The study led by Chinese archaeologists showed that a piece of a human fossil found in the Baishiya Karst Cave in Xiahe County, Gansu Province, is believed to belong to the ancient Denisovans, who lived around 160,000 years ago.

The findings have provided direct evidence of the Denisovans outside the Altai Mountains, and considerably prolonged human history on the Qinghai-Tibet Plateau, one of the highest and most ecologically-challenging places on the globe.

Stone tools excavated in the Baishiya cave [Credit: Xinhua News Agency/Li Jie]

According to Zhang Dongju, associate professor with the College of Earth and Environmental Sciences of Lanzhou University and leader of the excavation work, the team started excavation in 2018 and found over 1,400 stone artifacts and about 600 pieces of animal bone fossils in the cave.

Analysis of the stone artifacts and the fossils indicated that they were from more than 40,000 years ago and believed to belong to Paleolithic epoch.

Stone tools excavated in the Baishiya cave [Credit: Xinhua News Agency/Li Jie]

The Baishiya Karst Cave, located 3,280 meters above sea level, is thus the earliest archaeological site ever identified on the Qinghai-Tibet Plateau.

Chen Fahu, a lead scientist of the study and academician of Chinese Academy of Science, added that the abundant artifacts and animal bone fossils confirmed that humans had successfully adapted to the high-altitude environment.

The Xiahe Denisova fossil discovery site is the earliest known archaeological site on the Qinghai-Tibet Plateau [Credit: Xinhua News Agency/Li Jie]

The discoveries are expected to offer a clue to how ancient humans on East Asia continent had evolved, according to the researchers.

"As of now, we are not very sure if these stone artifacts and animal bones have direct connections with the Xiahe Denisovans, but we will continue on with further study," Chen said.

The findings were published in the journal Nature in May.

See also: First hominins on the Tibetan Plateau were Denisovans

Source: Xinhua News Agency [June 17, 2019]

Humans used northern migration routes to reach eastern Asia

By: Thomas Schmitt Attorney on May 29, 2019 / comment : 0 Archaeology, Asia, China, Early Humans, Earth Science, Mongolia, Palaeoclimate, Tibet

Northern and Central Asia have been neglected in studies of early human migration, with deserts and mountains being considered uncompromising barriers. However, a new study by an international team argues that humans may have moved through these extreme settings in the past under wetter conditions. We must now reconsider where we look for the earliest traces of our species in northern Asia, as well as the zones of potential interaction with other hominins such as Neanderthals and Denisovans.

The sand dunes of Mongol Els jutting out of the steppe in Mongolia. Many of these desert barriers only appeared after the Last Glacial Maximum (~20,000 years ago) [Credit: Nils Vanwezer]

Archaeologists and palaeoanthropologists are increasingly interested in discovering the environments facing the earliest members of our species, Homo sapiens, as it moved into new parts of Eurasia in the Late Pleistocene (125,000-12,000 years ago). Much attention has focused on a 'southern' route around the Indian Ocean, with Northern and Central Asia being somewhat neglected.

However, in a paper published in PLOS ONE, scientists of the Max Planck Institute for the History of Human Science in Jena, Germany, and colleagues at the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, China, argue that climate change may have made this a particularly dynamic region of hominin dispersal, interaction, and adaptation, and a crucial corridor for movement.

'Heading North' Out of Africa and into Asia

"Archaeological discussions of the migration routes of Pleistocene Homo sapiens have often focused on a 'coastal' route from Africa to Australia, skirting around India and Southeast Asia," says Professor Michael Petraglia of the Max Planck Institute for the Science of Human History, a co-author of the new study. "In the context of northern Asia, a route into Siberia has been preferred, avoiding deserts such as the Gobi."

Yet over the past ten years, a variety of evidence has emerged that has suggested that areas considered inhospitable today might not have always been so in the past. "Our previous work in Saudi Arabia, and work in the Thar Desert of India, has been key in highlighting that survey work in previously neglected regions can yield new insights into human routes and adaptations," says Petraglia.

Ancient lake landforms around Biger Nuur, Mongolia, which is evidence of larger lake sizes in the past [Credit: Nils Vanwezer]

Indeed, if Homo sapiens could cross what is now the Arabian Deserts then what would have stopped it crossing other currently arid regions such as the Gobi Desert, the Junggar Basin, and the Taklamakan Desert at different points in the past? Similarly, the Altai Mountains, the Tien Shan and the Tibetan Plateau represent a potentially new high altitude window into human evolution, especially given the recent Denisovan findings from Denisova Cave in Russia and at the Baishiya Karst Cave in China.

Nevertheless, traditional research areas, a density of archaeological sites, and assumptions about the persistence of environmental 'extremes' in the past has led to a focus on Siberia, rather than the potential for interior routes of human movement across northern Asia.

A "Green Gobi"?

Indeed, palaeoclimatic research in Central Asia has increasingly accumulated evidence of past lake extents, past records of changing precipitation amounts, and changing glacial extents in mountain regions, which suggest that environments could have varied dramatically in this part of the world over the course of the Pleistocene. However, the dating of many of these environmental transitions has remained broad in scale, and these records have not yet been incorporated into archaeological discussions of human arrival in northern and Central Asia.

Illustrated dispersal routes from the results of the Least Cost Path analysis. The three routes  from the "wet" simulations and the single route from the "dry" simulation are presented together in conjunction with palaeoclimatic extents (glaciers and palaeolakes) [Credit: Nils Vanwezer and Hans Sell]

"We factored in climate records and geographical features into GIS models for glacials (periods during which the polar ice caps were at their greatest extent) and interstadials (periods during the retreat of these ice caps) to test whether the direction of past human movement would vary, based on the presence of these environmental barriers," says Nils Vanwezer, PhD student at the Max Planck Institute for the Science of Human History and a joint lead-author of the study.

"We found that while during 'glacial' conditions humans would indeed likely have been forced to travel via a northern arc through southern Siberia, during wetter conditions a number of alternative pathways would have been possible, including across a 'green' Gobi Desert," he continues. Comparisons with the available palaeoenvironmental records confirm that local and regional conditions would have been very different in these parts of Asia in the past, making these 'route' models a definite possibility for human movement.

Where did you come from, where did you go?

"We should emphasize that these routes are not 'real', definite pathways of Pleistocene human movement. However, they do suggest that we should look for human presence, migration, and interaction with other hominins in new parts of Asia that have been neglected as static voids of archaeology," says Dr. Patrick Roberts also of the Max Planck Institute for the Science of Human History, co-author of the study. "Given what we are increasingly discovering about the flexibility of our species, it would be of no surprise if we were to find early Homo sapiens in the middle of modern deserts or mountainous glacial sheets."

"These models will stimulate new survey and fieldwork in previously forgotten regions of northern and Central Asia," says Professor Nicole Boivin, Director of the Department of Archaeology at the Max Planck Institute for the Science of Human History, and co-author of the study. "Our next task is to undertake this work, which we will be doing in the next few years with an aim to test these new potential models of human arrival in these parts of Asia."

Source: Max Planck Society [May 29, 2019]

Origins of cannabis traced back 28 million years to Tibetan Plateau

By: Thomas Schmitt Attorney on May 21, 2019 / comment : 0 Asia, Fossils, Palaeontology, Tibet

The origin of marijuana has finally been discovered and it dates back 28 million years to the Tibetan plateau, 10,700ft (3km) above sea level.

Credit: CBD School

Researchers analysed pollen fossils of the plant and found it slowly dispersed over millennia to Europe, China and India.

It has long been known cannabis originated in Central Asia but its exact location had remained a mystery until now.

Archaeological evidence of its use as a drug dates back to to 2,700 BC in the nearby Xinjiang region north west of China.

A team of researchers led by the University of Vermont in the US examined 155 existing fossil pollen studies from Asia in order to 'to reconstruct the evolutionary and human related history of Cannabis in Asia', said the authors in the report.

By looking at genetic analysis and fossils of cannabis pollen, they pinpointed the origins of its growth to 28 million years ago to the area of Qinghai lake on the Tibetan plateau.

They mapped the fossil data and found the oldest pollen fossil dates to 19.6 millions BC where it was likely cultivated by humans, given that both hem crop and fruits seeds fossils were also found at archaeological sites.

The plateau in the southwest of China measures 14,800 ft (4,500 m) above sea level at its peak and the lake sits at 10,700ft (3km) up the range.

The area overlaps with the first hunter and gatherer community that evolved in Asia, although no link has been made between the two.

Based on their analysis, the researchers found evidence the cannabis strain of hemp first disseminated to Europe and then East to China followed by India due to tectonic movements in the Earth that caused land mass to move closer to each other.

The flowering tops of cannabis strains such as hemp plant produce cannabinoids, which have been used to make the cannabis drug.

One reason the origins of the plant have been so hard to trace is because the leaves of cannabis plants - such as hemp - don't create very good print fossils, and only two collections of the plant fossil exist.

In contrast, hundreds of pollen fossils have been found and analysed, which the current study reviewed.

While widely known as a drug, the cannabis plant in fact had may functions for communities that used its plant fibres, for providing cordage and textiles, for example.

Carbonised hemp fibres, found with silk and spinning wheels, date to 5,600 BC, in Henan Province, China.

Scientists also put down the appearance of cannabis elsewhere in the world down to tectonic movements of the earth, rather than humans migrating with it.

The researchers wrote: 'Early floristic exchanges between India and Asia were shaped by plate tectonics,' the researchers wrote in their paper.

'As the Indian plate migrated towards the Asian plate, it made a 'glancing contact' with Sumatra 57 [million years ago], followed by Burma, and then a 'hard collision' with Tibet 35 [million years ago].

'The glancing contact between continents resulted in floristic exchanges during the Eocene.'

'Cannabis holds significance in human history and life today as a triple-use crop. First, its fruits (seeds) provide valuable protein and essential fatty acids', wrote the researchers.

Archaeological evidence in a food context dates back to 10,000 BC in Japan.

The full report was published in the journal Vegetation History and Archaeobotany.

Author: Yuan Ren | Source: Daily Mail [May 21, 2019]

More on First hominins on the Tibetan Plateau were Denisovans

By: Thomas Schmitt Attorney on May 07, 2019 / comment : 0 Anthropology, Early Humans, Fossils, Tibet

The Tibetan Plateau, as Earth's "Third Pole," was reported to be first occupied by modern humans probably armed with blade technology as early as 40 ka BP. However, no earlier hominin groups had been found or reported on the Tibetan Plateau until a recent study was published by Chinese researchers.

A virtual reconstruction of the mandible [Credit: Jean-Jacques Hubrin]

A joint research team led by CHEN Fahu from the Institute of Tibetan Plateau Research of the Chinese Academy of Sciences and ZHANG Dongju from the Lanzhou University reported their studies on a human mandible found in Xiahe, on the Northeastern Tibetan Plateau. The findings were published in Nature.

The researchers found that the mandible came from an individual who belonged to a population closely related to the Denisovans first found in Siberia. This population occupied the Tibetan Plateau in the Middle Pleistocene and adapted to this low-oxygen environment long before the arrival of modern Homo sapiens in the region.

So far, Denisovans are only known from a small collection of fossil fragments from Denisova Cave in Siberia. Traces of Denisovan DNA are found in present-day Asian, Australian and Melanesian populations, suggesting that these ancient hominins may have once been widespread.

The Xiahe mandible, only represented by its right half, was found in 1980 in Baishiya Karst Cave [Credit: © Dongju Zhang, Lanzhou University]

This study confirms for the first time that Denisovans not only lived in East Asia but also on the high-altitude Tibetan Plateau. It also indicates that the previously found possible introgression of Denisovan DNA (EPAS1) into modern Tibetans and Sherpas, who mainly live on the high-altitude Tibetan Plateau and surrounding regions today, is probably derived or inherited locally on Tibetan Plateau from Xiahe hominin represented by this Xiahe mandible.

The reported Xiahe mandible was found on the Tibetan Plateau in the Baishiya Karst Cave in Xiahe, China. Researchers managed to extract collagen from one of the molars, which they then analysed using ancient protein analysis. Ancient protein data showed that the Xiahe mandible belonged to a hominin population closely related to the Denisovans from Denisova Cave.

The robust primitive shape of the mandible and the very large molars still attached to it suggest that this mandible once belonged to a Middle Pleistocene hominin sharing anatomical features with Neandertals and specimens from the Denisova Cave.

Zhang Dongju (upper right in the ditch) led the excavation team at the Baishi Cliff cave in 2018 [Credit: Zhang Dongju]

Attached to the mandible was a heavy carbonate crust. By applying U-series dating to the crust, the researchers found that the Xiahe mandible is at least 160,000 years old, representing a minimum age of human presence on the Tibetan Plateau.

The similarities between the Xiahe mandible and other Chinese specimens confirm the presence of Denisovans among the current Asian fossil record. The current study paves the way towards a better understanding of the evolutionary history of Middle Pleistocene hominins in East Asia.

Source: Chinese Academy of Sciences [May 07, 2019]

Origin of Sino-Tibetan language family revealed by new research

By: Thomas Schmitt Attorney on May 06, 2019 / comment : 0 Anthropology, Asia, China, Linguistics, Tibet

The Sino-Tibetan language family includes early literary languages, such as Chinese, Tibetan, and Burmese, and is represented by more than 400 modern languages spoken in China, India, Burma, and Nepal. It is one of the most diverse language families in the world, spoken by 1.4 billion speakers. Although the language family has been studied since the beginning of the 19th century, scholars' knowledge of the origin of these languages is still severely limited.

Harvesting foxtail millet (Setaria italica) in Taiwan [Credit: © Chih-hung Yang]

An interdisciplinary study published in Proceedings of the National Academy of Sciences, led by scientists of the Centre des Recherches Linguistiques sur l'Asie Orientale (Paris), the Max Planck Institute for the Science of Human History (Jena), and the Centre de Recherches en Mathématiques de la Décision (Paris), now sheds new light on the place and date of the origin of these languages. Based on a phylogenetic study of 50 ancient and modern Sino-Tibetan languages, the scholars conclude that the Sino-Tibetan languages originated among millet farmers, located in North China, around 7,200 years ago.

During the past 10,000 years, two of the world's largest language families emerged, one in the west and one in the east of Eurasia. Together, these families account for nearly 60% of the world's population: Indo-European (3.2 billion speakers), and Sino-Tibetan (1.4 billion).

Presumed pathways of the expansion of non-Sinitic Sino-Tibetan languages, contrasted with findings of early domesticates and early Neolithic cultures in China [Credit: J.-M. List and H. Sell]

The Sino-Tibetan family comprises about 500 languages spoken across a wide geographic range, from the west coast of the Pacific to Nepal, India, and Pakistan. Speakers of these languages have played a major role in human prehistory, giving rise to early high cultures China, Tibet, Burma, and Nepal. However, while archaeogeneticists, phylogeneticists, and linguists have energetically discussed the origins of the Indo-European language family, the formation of Sino-Tibetan languages has previously received little attention.

One of the world's most diverse language families

"The Sino-Tibetan language family is one of the most diverse families in the world. It includes all of the different types of morphological systems, ranging from isolating languages, such as Chinese, Burmese, and Tujia, to polysynthetic languages, such as Gyalrongic and Kiranti languages," explains Guillaume Jacques of the Centre des Recherches Linguistiques sur l'Asie Orientale, co-first author of the study. "While our knowledge of how to compare these languages linguistically is improving, important aspects of the development of their sound systems and their grammar remain poorly understood."

A database of core words from 50 Sino-Tibetan languages

In order to shed light on the complex history of these languages, the scholars assembled a lexical database containing core vocabulary from 50 Sino-Tibetan languages. This database, published here for the first time, includes ancient languages spoken 1000 and more years ago, such as Old Chinese, Old Burmese, and Old Tibetan, as well as modern languages documented by field work.

Linguistic comparison of words meaning “cloud” across different Sino-Tibetan languages in the lexical database [Credit: © Johann-Mattis List]

"In order to compare these languages in a transparent way, we developed a specific annotation framework that allows us not only to mark which words we identify as sharing a common origin, but also which sounds in the words we think are related," says Johann-Mattis List of the Max Planck Institute for the Science of Human History, who led the study.

"A particular problem in identifying the truly related words were the numerous cases where languages borrowed words from each other," mentions Jacques. "Luckily, we know the history of particular languages rather well and could rely on techniques that we developed before to reveal the true history concealed by these borrowings."

Evolutionary trees suggest that the language family originated about 7200 years ago

Using powerful computational phylogenetic methods, the team inferred the most probable relationships between these languages and then estimated when these languages might have originated in the past.

A basketful of harvested ears of foxtail millet (Setaria italica) [Credit: © Chih-hung Yang]

"We find clear evidence for seven major subgroups with a complex pattern of overlapping signals beyond that level," says Simon J. Greenhill of the Max Planck Institute for the Science of Human History. "Our estimates suggest that the ancestral language has arisen around 7,200 years ago."

An agricultural analysis reveals the most likely origin and expansion scenario of the language family

To further resolve the complex pathways of the evolution of the Sino-Tibetan languages, the authors looked at related words describing domesticates, because they may reveal how agricultural knowledge spread through the region. This agricultural analysis suggests an origin of the Sino-Tibetan family in Northern Chinese communities of millet farmers of the Neolithic cultures of late Cishan and early Yangshao.


"The most likely expansion scenario of the languages involves an initial separation between an Eastern group, from which the Chinese dialects evolved, and a Western group, which is ancestral to the rest of the Sino-Tibetan languages," summarizes Laurent Sagart of the Centre des Recherches Linguistiques sur l'Asie Orientale, co-first author of the study, who carried out the agricultural analysis.

"We are very excited about our findings," says List. "Our approach combines robust, traditional scholarship with cutting-edge computational methods within a computer-assisted framework that allows us to use our knowledge of today's languages as a key to their past."

Source: Max Planck Institute for the Science of Human History [May 06, 2019]

First hominins on the Tibetan Plateau were Denisovans

By: Thomas Schmitt Attorney on May 01, 2019 / comment : 0 Anthropology, Asia, Early Humans, Fossils, Genetics, Tibet

Denisovans - an extinct sister group of Neanderthals - were discovered in 2010, when a research team led by Svante Pääbo from the Max Planck Institute for Evolutionary Anthropology (MPI-EVA) sequenced the genome of a fossil finger bone found at Denisova Cave in Russia and showed that it belonged to a hominin group that was genetically distinct from Neanderthals.

The Xiahe mandible, only represented by its right half, was found in 1980 in Baishiya Karst Cave [Credit: Dongju Zhang, Lanzhou University]

"Traces of Denisovan DNA are found in present-day Asian, Australian and Melanesian populations, suggesting that these ancient hominins may have once been widespread," says Jean-Jacques Hublin, director of the Department of Human Evolution at the MPI-EVA. "Yet so far the only fossils representing this ancient hominin group were identified at Denisova Cave."

Mandible from Baishiya Karst Cave

In their new study, the researchers now describe a hominin lower mandible that was found on the Tibetan Plateau in Baishiya Karst Cave in Xiahe, China. The fossil was originally discovered in 1980 by a local monk who donated it to the 6th Gung-Thang Living Buddha who then passed it on to Lanzhou University.

Since 2010, researchers Fahu Chen and Dongju Zhang from Lanzhou University have been studying the area of the discovery and the cave site from where the mandible originated. In 2016, they initiated a collaboration with the Department of Human Evolution at the MPI-EVA and have since been jointly analysing the fossil.

While the researchers could not find any traces of DNA preserved in this fossil, they managed to extract proteins from one of the molars, which they then analysed applying ancient protein analysis.

"The ancient proteins in the mandible are highly degraded and clearly distinguishable from modern proteins that may contaminate a sample," says Frido Welker of the MPI-EVA and the University of Copenhagen. "Our protein analysis shows that the Xiahe mandible belonged to a hominin population that was closely related to the Denisovans from Denisova Cave."

Primitive shape and large molars

The researchers found the mandible to be well-preserved. Its robust primitive shape and the very large molars still attached to it suggest that this mandible once belonged to a Middle Pleistocene hominin sharing anatomical features with Neanderthals and specimens from the Denisova Cave.

The cave is facing southeast and about 40 meters above the modern Jiangla riverbed in front of it. It is both a locally  famous Buddhist cave and a famous tourist place [Credit: Dongju Zhang, Lanzhou University]

Attached to the mandible was a heavy carbonate crust, and by applying U-series dating to the crust the researchers found that the Xiahe mandible is at least 160,000 years old. Chuan-Chou Shen from the Department of Geosciences at National Taiwan University, who conducted the dating, says: "This minimum age equals that of the oldest specimens from the Denisova Cave".

"The Xiahe mandible likely represents the earliest hominin fossil on the Tibetan Plateau," says Fahu Chen, director of the Institute of Tibetan Research, CAS. These people had already adapted to living in this high-altitude low-oxygen environment long before Homo sapiens even arrived in the region. Previous genetic studies found present-day Himalayan populations to carry the EPAS1 allele in their genome, passed on to them by Denisovans, which helps them to adapt to their specific environment.

The entrance of the cave is relatively flat with a gentle slope up to the inside, where two small trenches were plotted in 2018 [Credit: Dongju Zhang, Lanzhou University]

"Archaic hominins occupied the Tibetan Plateau in the Middle Pleistocene and successfully adapted to high-altitude low-oxygen environments long before the regional arrival of modern Homo sapiens," says Dongju Zhang.

According to Hublin, similarities with other Chinese specimens confirm the presence of Denisovans among the current Asian fossil record. "Our analyses pave the way towards a better understanding of the evolutionary history of Middle Pleistocene hominins in East Asia."

The study is published in Nature.

Source: Max Planck Society [May 01, 2019]