воскресенье, 2 июня 2019 г.

Could some chimpanzees’ crustacean crave yield clues about human evolution?

Why do we fish? At some point eons ago, our primarily fruit-eating ancestors put their hands in the water to catch and eat aquatic life, inadvertently supplementing their diet with nutrients that initiated a brain development process that eventually led to us. But how did this begin?

Could some chimpanzees' crustacean crave yield clues about human evolution?
Chimpanzee fishing for crabs [Credit: Kathelijne Koops]

Now, according to a research team from Kyoto University, one potential clue may have surfaced thanks to observations of our closest genetic relatives: chimpanzees. The scientists report the first ever evidence of wild chimps habitually catching and consuming freshwater crabs.
Writing in the Journal of Human Evolution, the team describes year-round, fresh water crab-fishing behavior — primarily among female and infant chimpanzees — living in the rainforest of the Nimba Mountains in Guinea, West Africa.

Could some chimpanzees' crustacean crave yield clues about human evolution?
Fresh-water crab [Credit: Kathelijne Koops]

«The aquatic fauna our ancestors consumed likely provided essential long-chain polyunsaturated fatty acids, required for optimal brain growth and function,» explains first author Kathelijne Koops from the University of Zurich and Kyoto University’s Leading Graduate Program in Primatology and Wildlife Science.
«Further, our findings suggest that aquatic fauna may have been a regular part of hominins’ diets and not just a seasonal fallback food.»

Could some chimpanzees' crustacean crave yield clues about human evolution?
The Nimba Mountains in Guinea where chimpanzees call home
[Credit: Kathelijne Koops]

The study began in 2012 when the researchers first observed the chimpanzees fishing for crabs. For two years, they documented the demographics and behavior of these chimps, while also analyzing and comparing the nutritional value of the crabs to other foods in the chimpanzees’ diet.
Crabbing, they learned, not only took place year-round — without regard to season or fruit availability — but intriguingly was negatively correlated with the chimps’ consumption of ants, another diet staple. Mature males were the least likely to consume aquatic fauna.

Chimpanzees have a mainly vegetarian diet, but do occasionally eat meat. Researchers at the University 

of Zurich have now shown for the first time that chimpanzees also eat crabs. In the rainforest 

of Guinea, the researchers observed how chimpanzees regularly fish for crabs 

[Credit: Kathelijne Koops]

«Energy and sodium levels in large crabs are comparative with ants,» explains Koops, «leading us to hypothesize that crabs may be an important year-round source of protein and salts for females — especially when pregnant or nursing — and for growing juveniles.»
The study further sheds light on our own evolution, by showing that fishing behaviors may not be restricted by habitat as initially assumed.

Chimpanzee mother fishing for freshwater crabs while her offspring practices 

[Credit: Kyoto University/Kathelijne Koops]

«This isn’t the first case of non-human primates eating crabs,» points out senior co-author Tetsuro Matsuzawa, «but it is the first evidence of apes other than humans doing so. Notably, previous observations were from monkey species in locations consistent with aquatic faunivory — lakes, rivers, or coastlines — and not in closed rainforest.»

«It’s exciting to see a behavior like this that allows us to improve our understanding of what drove our ancestors to diversify their diet.»

Source: Kyoto University [May 29, 2019]



New research shows how habitat loss can destabilise ecosystems

An international study has revealed new evidence to help understand the consequences of habitat loss on natural communities.

New research shows how habitat loss can destabilise ecosystems
This study found that the specific ways in which habitat is lost is important
to the response of biodiversity [Credit: Swansea University]

The research, co-authored by Swansea University’s Dr Miguel Lurgi, shows the specific ways in which human activities destroy habitat is a key factor to understanding the effects of such destruction on the stability and functioning of biological communities.

The paper, published in scientific journal Nature Communications, asks whether putting the focus solely on species diversity may overlook other facets of the way biological communities respond to habitat destruction.

Daniel Montoya, researcher at the Theoretical and Experimental Ecology Station in Moulis, France, also a co-author, said: «Ecologists and practitioners tend to assess the impact of human activities on biodiversity by measuring the extinction rates of species.

«However, biodiversity comprises elements other than single species, such as the interactions between species and their stability over time and space. These additional, and sometimes overlooked, properties are key to the functioning of ecosystems. They are the missed component of biodiversity loss that accompanies or precede species extinctions.»

This study found that the specific ways in which habitat is lost is important to the response of biodiversity.

Dr Montoya added: «Natural habitats can be destroyed randomly or in a clustered way — for example, by the construction of a road or the creation of new urban areas, respectively. The spatial configuration of this loss differentially constrains the mobility of individual animals, which further impacts biodiversity and the stability of populations in the remaining fragments of intact habitat.»

The researchers say a logical question now emerges — how is habitat destroyed in real landscapes around the world?

«It depends on the spatial scale we are looking at. Yet, we explored several scenarios of habitat loss and our results suggest that community responses are approximately gradual and predictable based on degree of spatial autocorrelation of the lost habitat,» said Dr Lurgi.

This study relates to recent research exploring changes in local diversity following global change, currently under a subject of heated debate.

«We suggest that, irrespective of a positive, negative or neutral change in local diversity, spatial patterns of habitat loss largely influence the structure and dynamics of biodiversity in very different, contrasting ways.»

Dr Lurgi, a lecturer at Swansea’s Department of Biosciences, previously worked at the renowned CNRS in France and became involved in the paper as part of his own research focusing on the disassembly dynamics of ecological networks.

The authors hope their findings will be used to help inform environmental science and policy making in the future. They would like to see aspects of community structure and stability as well as the spatial configuration of habitat loss incorporated into conservation planning.

Dr Lurgi added: «I think it is important to develop theory and models to help us understand these effects and allow us to come up with better ways to tackle habitat loss and other sources of anthropogenic change to better conserve biodiversity.»

Read more about Dr Lurgi’s research in The Conversation.

Source: Swansea University [May 30, 2019]



Ancient underground ‘city’ investigated by Iranian archaeologists

A team of archaeologists has commenced an extensive research on a centuries-old underground “city”, which is located in Salehabad district of Hamedan province, west-central Iran, ISNA reported on Friday.

Ancient underground 'city' investigated by Iranian archaeologists
Credit: Mizan Online News Agency/Adel Bakhoda

The site, estimated to date 800 years, was found some three years ago but the story didn’t publicized in order to prevent any possible looting from the underground city before the appropriation of credits for the beginning of studies, a provincial tourism official Ahmad Torabi said.
The official said that initial works found at the site are pieces of pottery, which are related to the Islamic and earlier eras, emphasizing “We need more time to do further research and exploration so that we can fully investigate this area.”

Ancient underground 'city' investigated by Iranian archaeologists

Ancient underground 'city' investigated by Iranian archaeologists

Ancient underground 'city' investigated by Iranian archaeologists

Ancient underground 'city' investigated by Iranian archaeologists

Ancient underground 'city' investigated by Iranian archaeologists
Credit: Mizan Online News Agency/Adel Bakhoda

“At the time when Russian soldiers crossed the area [during the World War II], the men of the region concealed their families in the underground city so that no one noticed their presence,” Torabi added.
It is the third underground city being discovered in Hamedan province after Samen and Arzan-Fud, which some archaeologists attribute the two to the times of Medes (678 – 549 BC) so that Hamedan may be named as a pioneering region of troglodyte architecture in the country, he explained.

Ancient underground 'city' investigated by Iranian archaeologists

Ancient underground 'city' investigated by Iranian archaeologists

Ancient underground 'city' investigated by Iranian archaeologists

Ancient underground 'city' investigated by Iranian archaeologists

Ancient underground 'city' investigated by Iranian archaeologists
Credit: Mizan Online News Agency/Adel Bakhoda

Last October, Hamedan hosted the 3rd International Troglodytic Architecture Conference in which tens of experts, researches and academia discussed troglodyte-associated architecture, culture and technology.

Modern Hamedan largely lies on ancient Ecbatana, which was the capital of Media and subsequently a summer residence of the Achaemenian kings who ruled Persia from 553 to 330 BC.

Source: Tehran Times [May 30, 2019]



Spitzer captures stellar family portrait

In this large celestial mosaic taken by NASA’s Spitzer Space Telescope, there’s a lot to see, including multiple clusters of stars born from the same dense clumps of gas and dust. Some of these clusters are older than others and more evolved, making this a generational stellar portrait.

Spitzer captures stellar family portrait
A mosaic by NASA’s Spitzer Space Telescope of the Cepheus C and Cepheus B regions.
This image combines data from Spitzer’s IRAC and MIPS instruments
[Credit: NASA/JPL-Caltech]

The grand green-and-orange delta filling most of the image is a faraway nebula, or a cloud of gas and dust in space. Though the cloud may appear to flow from the bright white spot at its tip, it is actually what remains of a much larger cloud that has been carved away by radiation from stars. The bright region is illuminated by massive stars, belonging to a cluster that extends above the white spot. The white color is the combination of four colors (blue, green, orange and red), each representing a different wavelength of infrared light, which is invisible to human eyes. Dust that has been heated by the stars’ radiation creates the surrounding red glow.
On the left side of this image, a dark filament runs horizontally through the green cloud. A smattering of baby stars (the red and yellow dots) appear inside it. Known as Cepheus C, the area is a particularly dense concentration of gas and dust where infant stars form. The dark vein of material will eventually be dispersed by strong winds produced as the stars get older, as well as when they eventually explode and die. This will create an illuminated puffed-up region that will look similar to the bright red-and-white region on the large nebula’s upper-right side. The region is called Cepheus C because it lies in the constellation Cepheus, which can be found near the constellation Cassiopeia. Cepheus C is about 6 light-years long and lies about 40 light-years from the bright spot at the tip of the nebula.

Spitzer captures stellar family portrait
An annotated mosaic by NASA’s Spitzer Space Telescope of the Cepheus C and Cepheus B regions.
This image combines data from Spitzer’s IRAC and MIPS instruments
[Credit: NASA/JPL-Caltech]

A second large nebula can be seen on the right side of the image, with a star cluster located just above it. Known as Cepheus B, the cluster sits within a few thousand light-years of our Sun. A study of this region using Spitzer data found that the dramatic collection is about 4 million to 5 million years old—slightly older than those in Cepheus C.
In that way, the mosaic is a veritable family portrait, featuring infants, parents and grandparents of star-forming regions: Stars form in dense clouds of material, like the dark vein that makes up Cepheus C. As the stars grow, they produce winds that blow the gas and dust outward, to form beautiful, illuminated nebulas like the bright white spot at the top of the larger nebula. Finally, the dust and gas disperse, and the star clusters stand alone in space, as with Cepheus B.

The amazing features in this image don’t end there. Look closely for the small, red hourglass shape just below Cepheus C. This is V374 Ceph. Astronomers studying this massive star have speculated that it might be surrounded by a nearly edge-on disk of dark, dusty material. The dark cones extending to the right and left of the star are a shadow of that disk.

The smaller nebula on the right side of the image includes two particularly interesting objects. In the upper-left portion of the nebula, try to find a blue star crowned by a small, red arc of light. This «runaway star» is plowing through the gas and dust at a rapid clip, creating a shock wave, or «bow shock,» in front of itself.

Also hidden within this second nebula, a small cluster of newborn stars illuminates the dense cloud of gas and dust where they formed. This region is more obvious in the image below, which uses data from just one of Spitzer’s instruments. (The top image includes data from two instruments.) In the image below, this feature appears as a bright teal splash.

Source: NASA [May 31, 2019]



The last of the ‘Gorillas in the Mist’ is presumed dead

The last of the «Gorillas in the Mist» — made famous by renowned American primatologist Dian Fossey — is believed to have died.

The last of the 'Gorillas in the Mist' is presumed dead
Poppy pictured here in August 2015 was the last living mountain gorilla studied
by famed zoologist Dian Fossey [Credit: Dian Fossey Gorilla Fund]

A gorilla known as Poppy, who would have turned 43 on April 1, has not been seen by trackers since August last year, according to Fossey’s namesake nonprofit organization.

Poppy was born nine years after Fossey established a camp within Rwanda’s Volcanoes National Park in 1967 as part of an effort to study the area’s vanishing mountain gorilla population.

Fossey was killed in Rwanda over 30 years ago but her nonprofit said in a statement about Poppy’s death that Fossey often wrote of the young gorilla in her journals. She described Poppy as a «little darling … winsome and appealing. She could do no wrong.»

The Fossey Fund said Poppy hailed from one of the area’s «royal families.» Her mother, Effie, was the powerful matriarch whose members are now spread across many gorilla groups in the national park. Poppy’s other well-known relatives include two silverbacks, Cantsbee and Isabukuru, as well as her sister, Maggie, who was a favorite of Sigourney Weaver while filming the Academy Award-winning film «Gorillas in the Mist,» which was adapted from a book by Fossey.

The last of the 'Gorillas in the Mist' is presumed dead
A young Poppy studies famed primatologist Dian Fossey in 1977
[Credit: Dian Fossey Gorilla Fund]

«Being able to observe Poppy over so many stages of life gave researchers a wealth of knowledge,» said Tara Stoinski, Fossey Fund President in a press statement. «She taught us so much about the rich social and reproductive lives of female gorillas, their dominance structure, and of course, their personalities.»
Throughout her life, Poppy would surprise those monitoring her by transferring to different groups of mountain gorillas. Then two years ago, Poppy stunned her trackers when, at 41, she became the oldest recorded mountain gorilla to give birth.

«Poppy broke the mould for what we know about mountain gorilla females — transferring at an older age, joining a very young and inexperienced male, having a baby so late in life,» explained Veronica Vecellio, Fossey Fund gorilla program senior advisor.

«It is so wonderful that we know about her infancy from Dian Fossey’s journals. She was one of Fossey’s favorites, and we all felt such privilege to know her and observe her in her final years. Surely, this means we will remember her forever,» Vecellio added.

The Fossey Fund said Poppy left five children, as well as another sister, Mahane.

When Fossey arrived at the Virunga mountains in 1967 she found a species on the brink — with just 240 gorillas left. Five decades later, the population is continuing to grow with the latest census last year revealing a population of 604 as of June 2016.

Author: Lauren Said-Moorhouse | Source: CNN [May 31, 2019]



3,000-year-old fingerprints found at ancient village in Al Ain

Three-thousand-year old fingerprints have been found on ancient bricks at an Iron Age village in Al Ain. The impressions are believed to come from workers who were building a wall at Hili 2 — a Unesco World Heritage Site.

3,000-year-old fingerprints found at ancient village in Al Ain
The fingerprints of a worker who helped build a wall in ancient Al Ain 
[Credit: DCT — Abu Dhabi]

The major discovery provides evidence of a skilled network of craftsmen adept at construction in what is now modern-day UAE.
Revealed this week, the find also confronts stereotypes that the early Emiratis lived bleak, short lives. Instead they show a vibrant community of people thriving in a harsh landscape.

“We are thrilled with the results of our investigations,” said Mohamed Al Mubarak, chairman of the Department of Culture and Tourism — Abu Dhabi. “The discoveries at Hili 2 bring previously unknown details about our past to light, for us and for future generations.”

3,000-year-old fingerprints found at ancient village in Al Ain
Iron Age mudbricks with 3000 year old finger impressions 
[Credit: DCT — Abu Dhabi]

While ancient prints have been found before, these new examples are remarkably well-preserved. Experts from DCT are now considering sending them for forensic analysis to learn more about the people who left their mark.
«From the prints we can figure out the age of the group, » said Ali Al Meqbali, DCT’s head of archaeology in Al Ain. «It will also help us understand the building techniques.»

Excavations by at least five archaeologists over the past few months have shed new light on how Iron Age people lived, cooked, grew crops and socialised. Clay seals and communal ovens have also been found.

3,000-year-old fingerprints found at ancient village in Al Ain
Houses excavated in Hili 2 in Al Ain 
[Credit: DCT — Abu Dhabi]

Hili 2 — located to the northeast of Al Ain town centre — was first excavated in the 1970s when the existence of well-preserved houses was revealed. But teams returned in 2018 to begin targeted, painstaking investigations on each house. The fruits of that arduous work are now being borne out.
The key question was how these people built walls. It is now believed that craftsmen used their hands to create indentations in the mud-bricks which then held the mortar — made of mud, stones and water — and bonded the wall together. Today these indentations are known as “frogs” and are a critical part of construction. Many bricks had these fingerprints but it is not yet clear how many people are involved.

“The research at Hili 2 reveals an unparalleled window into the past,” said Mr Al Mubarak. “The archaeological results illustrate how our ancestors used available materials, in a sophisticated and optimal fashion, to build houses and buildings that would last for millennia.”

3,000-year-old fingerprints found at ancient village in Al Ain
Iron Age oven (tannour) found at Hili 2 in Al Ain 
[Credit: DCT — Abu Dhabi]

Excavations have also revealed the existence of well-preserved ovens. Known as tannours, they are built of clay and contain burnt stones. It is believed the stones would have been heated and then sheep or goat meat would be cooked on them. These tannours were found not in individual houses but at communal spaces and it is likely they were used by families at special occasions. A clay seal with an engraving of a gazelle that was probably used for decoration or administration was also unearthed.
«It helps us understand the daily activities and lifestyle of this time,» said Mr Al Al Meqbali. «They cooked together and lived together.»

The new findings at Hili 2 — now being sent for further analysis — prove again how adaptable and skilled the people who lived here thousands of years ago were. A testament to their work is that 3,000 years on, many of the walls built by the people at Hili 2 are still standing.

3,000-year-old fingerprints found at ancient village in Al Ain
Clay seal with the engraving of a gazelle 
[Credit:  DCT — Abu Dhabi]

It also follows a wave of archaeological work by DCT over the past few years that has radically reshaped our understanding of the past.

Recent work on Marawah Island, for example, has shown the existence of an advanced Stone Age community who expertly exploited the resources around them. Elsewhere in Al Ain last year, archaeologists unearthed the remains of a 1,000-year-old mosque — thought to be the earliest yet discovered in the UAE.

Author: John Dennehy | Source: The National [May 31, 2019]



Old Oswestry Iron Age Hill Fort, Oswestry, North Wales, 2.6.19.Most of the photos here...

Old Oswestry Iron Age Hill Fort, Oswestry, North Wales, 2.6.19.

Most of the photos here show the complex vallate that surrounded the fort. It was in use from around 1000BCE to around 4th century CE.

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Earth recycles ocean floor into diamond

Traces of salt trapped in many diamonds show the stones are formed from ancient seabeds that became buried deep beneath the Earth’s crust, according to new research led by Macquarie University geoscientists in Sydney, Australia.

Earth recycles ocean floor into diamond
The diamond on your finger is most likely made of recycled seabed
cooked deep in the Earth [Credit: Macquarie University]

Most diamonds found at the Earth’s surface are formed this way; others are created by crystallization of melts deep in the mantle.

In experiments recreating the extreme pressures and temperatures found 200 kilometres underground, Dr Michael Förster, Professor Stephen Foley, Dr Olivier Alard, and colleagues at Goethe Universität and Johannes Gutenberg Universität in Germany, have demonstrated that seawater in sediment from the bottom of the ocean reacts in the right way to produce the balance of salts found in diamond.

The study, published in Science Advances, settles a long-standing question about the formation of diamonds. «There was a theory that the salts trapped inside diamonds came from marine seawater, but couldn’t be tested,» says lead author Michael. «Our research showed that they came from marine sediment.»

Diamonds are crystals of carbon that form beneath the Earth’s crust in very old parts of the mantle. They are brought to the surface in volcanic eruptions of a special kind of magma called kimberlite.

While gem diamonds are usually made of pure carbon, so-called fibrous diamonds, which are cloudy and less appealing to jewellers, often include small traces of sodium, potassium and other minerals that reveal information about the environment where they formed.

These fibrous diamonds are commonly ground down and used in technical applications like drill bits.

Fibrous diamonds grow more quickly than gem diamonds, which means they trap tiny samples of fluids around them while they form.

«We knew that some sort of salty fluid must be around while the diamonds are growing, and now we have confirmed that marine sediment fits the bill,» says Michael.

For this process to occur, a large slab of sea floor would have to slip down to a depth of more than 200 kilometres below the surface quite rapidly, in a process known as subduction in which one tectonic plate slides beneath another.

The rapid descent is required because the sediment must be compressed to more than four gigapascals (40,000 times atmospheric pressure) before it begins to melt in the temperatures of more than 800°C found in the ancient mantle.

To test the idea, team members at the Johannes Gutenberg Universität Mainz and Goethe Universität Frankfurt in Germany carried out a series of high-pressure, high-temperature experiments.

They placed marine sediment samples in a vessel with a rock called peridotite that is the most common kind of rock found in the part of the mantle where diamonds form. Then they turned up the pressure and the heat, giving the samples time to react with one another in conditions like those found at different places in the mantle.

At pressures between four and six gigapascals and temperatures between 800°C and 1100°C, corresponding to depths of between 120 and 180 kilometres below the surface, they found salts formed with a balance of sodium and potassium that closely matches the small traces found in diamonds.

«We demonstrated that the processes that lead to diamond growth are driven by the recycling of oceanic sediments in subduction zones,» says Michael.

«The products of our experiments also resulted in the formation of minerals that are necessary ingredients for the formation of kimberlite magmas, which transport diamonds to the Earth’s surface.»

Source: Macquarie University [May 30, 2019]



Ancient DNA tells the story of the first herders and farmers in east Africa

A collaborative study led by archaeologists, geneticists and museum curators is providing answers to previously unsolved questions about life in sub-Saharan Africa thousands of years ago. The results were published online in the journal Science.

Ancient DNA tells the story of the first herders and farmers in east Africa
Herders move goats through the Engaruka Basin in northern Tanzania’s Rift Valley.
Ancient DNA shows that this way of life spread to East Africa through multiple
population movements [Credit: Katherine Grillo]

Researchers from North American, European and African institutions analyzed ancient DNA from 41 human skeletons curated in the National Museums of Kenya and Tanzania, and the Livingstone Museum in Zambia.
«The origins of food producers in East Africa have remained elusive because of gaps in the archaeological record,» said co-first author Mary Prendergast, Ph.D., professor of anthropology and chair of humanities at Saint Louis University’s campus in Madrid, Spain. «This study uses DNA to answer previously unresolvable questions about how people were moving and interacting,» added Prendergast.

The research provides a look at the origins and movements of early African food producers. The first form of food production to spread through most of Africa was the herding of cattle, sheep and goats. This way of life continues to support millions of people living on the arid grasslands that cover much of sub-Saharan Africa.

Ancient DNA tells the story of the first herders and farmers in east Africa
Co-first author Mary Prendergast, Ph.D., is a professor of anthropology and chair
of humanities at Saint Louis University’s campus in Madrid, Spain
[Credit: Mary Prendergast]

«Today, East Africa is one of the most genetically, linguistically, and culturally diverse places in the world,» explains Elizabeth Sawchuk, Ph.D., a bioarchaeologist at Stony Brook University and co-first author of the study. «Our findings trace the roots of this mosaic back several millennia. Distinct peoples have coexisted in the Rift Valley for a very long time.»
Previous archaeological research shows that the Great Rift Valley of Kenya and Tanzania was a key site for the transition from foraging to herding. Herders of livestock first appeared in northern Kenya around 5000 years ago, associated with elaborate monumental cemeteries, and then spread south into the Rift Valley, where Pastoral Neolithic cultures developed.

The new genetic results reveal that this spread of herding into Kenya and Tanzania involved groups with ancestry derived from northeast Africa, who appeared in East Africa and mixed with local foragers there between about 4500-3500 years ago. Previously, the origins and timing of these population shifts were unclear, and some archaeologists hypothesized that domestic animals spread through exchange networks, rather than by movement of people.

Ancient DNA tells the story of the first herders and farmers in east Africa
Cattle graze along Lake Manyara in the Rift Valley of Tanzania.
Ancient DNA is shedding light on the earliest herders
in East Africa [Credit: Mary Prendergast]

After around 3500 years ago, herders and foragers became genetically isolated in East Africa, even though they continued to live side by side. Archaeologists have hypothesized substantial interaction among foraging and herding groups, but the new results reveal that there were strong and persistent social barriers that lasted long after the initial encounters.

Another major genetic shift occurred during the Iron Age around 1200 years ago, with movement into the region of additional peoples from both northeastern and western Africa. These groups contributed to ancient ancestry profiles similar to those of many East Africans today. This genetic shift parallels two major cultural changes: farming and iron-working.

The study provided insight into the history of East Africa as an independent center of evolution of lactase persistence, which enables people to digest milk into adulthood. This genetic adaptation is found in high proportions among Kenyan and Tanzanian herders today.

Prendergast and Sawchuk published a companion piece on their work in The Conversation.

Author: Jeanette Grider | Source: Saint Louis University [May 30, 2019]



Volcanic eruption witnessed by prehistoric humans

A volcanic eruption believed to be eye-witnessed by humans in prehistoric times happened 245,000 years later than originally expected, according to new research involving Curtin University researchers.

Volcanic eruption witnessed by prehistoric humans
Çakallar volcano, as seen from the southeast. The overlay is a 3D model of one of the Bronze Age prints,
known as the «Kula footprints» because they are in Kula Volcanic Geopark
[Credit: Erdal Gumus/Curtin University]

The research, published in Quaternary Science Reviews, aimed to determine the age of prehistoric footprints found in the ash layer produced by the Çakallar volcano eruption, which took place in the town of Kula in western Turkey thousands of years ago.
Along with the footprints, a rock painting was discovered in close proximity to the eruption site in the Kula UNESCO Geopark, in Manisa Province, Turkey. The painting, which illustrates the eruption of the volcano, highlights how humans from thousands of years ago were able to illustrate natural phenomena in their own way.

Lead Australian author Dr. Martin Danišík, from the John de Laeter Centre based at Curtin University, said previous studies suggested the footprints belonged to Homo neanderthalensis from the Pleistocene age, but the new findings indicated they may be younger than previously thought.

Volcanic eruption witnessed by prehistoric humans
From left to right: Ancient humans painted this illustration on a rock shelter near a volcano; a colour-enhanced version
of the rock art, which enhances the cone-shaped feature, the lower elongated line, the three-fingered handprints
and other details; a reconstructed version of the painting [Credit: Ulusoy et al., 2019]

«The footprints, widely known as ‘Kula footprints,’ were discovered in the 1960s when construction workers, who were moving volcanic rock away from one of the volcanoes in the area, found them well-preserved in fine-grained volcanic ash,» Dr. Danišík said.
«Our team was able to determine the age of the volcanic ash that preserved the footprints by using two different techniques. A radiogenic helium dating method was used to measure the eruption age of tiny zircon crystals, and the cosmogenic chlorine exposure dating method was used to measure the time that the volcanic rocks have been residing near the Earth’s surface.

«The two independent dating approaches showed internally consistent results and collectively suggest that the volcanic eruption was witnessed by Homo sapiens during the prehistoric Bronze Age, 4,700 years ago and 245,000 years later than originally reported.»

Volcanic eruption witnessed by prehistoric humans
A researcher takes a photo of a footprint for 3D modeling. It’s unclear if this print
belongs to a human or animal [Credit: Erdal Gumus]

The research also suggests that after the initial eruption, humans and their canine companions slowly approached the volcano, leaving distinctive footprints in the wet ash blanket on the surface. Volcanic activity continued, causing dark-colored volcanic rock to bury the ash and therefore preserve the footprints.
Dr. Danišík explained that the humans witnessed the final stages of the volcanic eruption from a safe distance, making it highly likely the Homo sapiens were also responsible for the rock paintings discovered close to the site.

«The rock painting is a fascinating connection to the footprints, as it showcases how humans from 4,700 years ago were able to paint natural processes, such as a volcanic eruption, in their own artistic way with limited tools and materials,» Dr. Danišík said.

Source: Curtin University [May 30, 2019]



Tree of life brought to scale by Yale scientists

Examples of biological scaling are everywhere. The paw of a mouse is smaller than the human hand. Our own organs and limbs typically scale with our body size as we develop and grow.

Tree of life brought to scale by Yale scientists
Detection of the DNA organelle (nucleoid) in diverse bacterial species,
by Sander Govers and William Gray [Credit: Jacobs-Wagner lab]

Scientists at Yale have shown that this same phenomenon exists at the subcellular level in the smallest bacteria, where the size of the nucleoid—the membrane-less region containing the cell’s genes—also scales with the size of a bacterial cell.

Absent a membrane or «envelope» associated with biological scaling in other life forms, scientists have remained unclear about the presence of scaling in bacteria for over a century.

Published in the journal Cell, researchers at the Yale Microbial Sciences Institute have concluded that this scaling effect occurs across different species of bacteria at the single-cell level, with the nucleoid growing at the same rate as the cell independently of changes in DNA content.

Led by Christine Jacobs-Wagner, William H. Fleming, MD Professor of Molecular, Cellular, and Developmental Biology, the research shows that the scaling trait was likely present billions of years ago, predating the development of intracellular membrane structures.

Alongside first authors William Gray and Sander Govers, graduate student and postdoctoral associate in the Jacobs-Wagner Lab, the work establishes for the first time that biological scaling exists across all three taxonomic domains of life: the Archaea, Eukarya, and now the Bacteria.

The findings identify general organizational principles and biophysical features of bacterial cells, expected to inform scientific advances looking into the constraints of how a cell is built.

Author: Jon Atherton | Source: Yale University [May 31, 2019]




https://t.co/hvL60wwELQ — XissUFOtoday Space (@xufospace) August 3, 2021 Жаждущий ежик наслаждается пресной водой после нескольких дней в о...