'Dragon man' fossil may replace Neanderthals as our closest relative

CELL PRESS

Research News

VIDEO: THIS VIDEO SHOWS A VIRTUAL RECONSTRUCTION OF THE HARBIN CRANIUM view more 

CREDIT: XIJUN NI

A near-perfectly preserved ancient human fossil known as the Harbin cranium sits in the Geoscience Museum in Hebei GEO University. The largest of known Homo skulls, scientists now say this skull represents a newly discovered human species named Homo longi or "Dragon Man." Their findings, appearing in three papers publishing June 25 in the journal The Innovation, suggest that the Homo longi lineage may be our closest relatives--and has the potential to reshape our understanding of human evolution.

"The Harbin fossil is one of the most complete human cranial fossils in the world," says author Qiang Ji, a professor of paleontology of Hebei GEO University. "This fossil preserved many morphological details that are critical for understanding the evolution of the Homo genus and the origin of Homo sapiens."

The cranium was reportedly discovered in the 1930s in Harbin City of the Heilongjiang province of China. The massive skull could hold a brain comparable in size to modern humans' but had larger, almost square eye sockets, thick brow ridges, a wide mouth, and oversized teeth. "While it shows typical archaic human features, the Harbin cranium presents a mosaic combination of primitive and derived characters setting itself apart from all the other previously-named Homo species," says Ji, leading to its new species designation of Homo longi.

Scientists believe the cranium came from a male individual, approximately 50 years old, living in a forested, floodplain environment as part of a small community. "Like Homo sapiens, they hunted mammals and birds, and gathered fruits and vegetables, and perhaps even caught fish," remarks author Xijun Ni, a professor of primatology and paleoanthropology at the Chinese Academy of Sciences and Hebei GEO University. Given that the Harbin individual was likely very large in size as well as the location where the skull was found, researchers suggest H. longi may have been adapted for harsh environments, allowing them to disperse throughout Asia.

CAPTION

This image shows comparisons among Peking Man, Maba, Jinniushan, Dali and Harbin crania (from left to right)

CREDIT

Kai Geng

Using a series of geochemical analyses, Ji, Ni, and their team dated the Harbin fossil to at least 146,000 years, placing it in the Middle Pleistocene, a dynamic era of human species migration. They hypothesize that H. longi and H. sapiens could have encountered each other during this era.

"We see multiple evolutionary lineages of Homo species and populations co-existing in Asia, Africa, and Europe during that time. So, if Homo sapiens indeed got to East Asia that early, they could have a chance to interact with H. longi, and since we don't know when the Harbin group disappeared, there could have been later encounters as well," says author Chris Stringer, a paleoanthropologist at the Nature History Museum in London.

Looking farther back in time, the researchers also find that Homo longi is one of our closest hominin relatives, even more closely related to us than Neanderthals. "It is widely believed that the Neanderthal belongs to an extinct lineage that is the closest relative of our own species. However, our discovery suggests that the new lineage we identified that includes Homo longi is the actual sister group of H. sapiens," says Ni.

Their reconstruction of the human tree of life also suggests that the common ancestor we share with Neanderthals existed even further back in time. "The divergence time between H. sapiens and the Neanderthals may be even deeper in evolutionary history than generally believed, over one million years," says Ni. If true, we likely diverged from Neanderthals roughly 400,000 years earlier than scientists had thought.

The researchers say that findings gathered from the Harbin cranium have the potential to rewrite major elements of human evolution. Their analysis into the life history of Homo longi suggest they were strong, robust humans whose potential interactions with Homo sapiens may have shaped our history in turn. "Altogether, the Harbin cranium provides more evidence for us to understand Homo diversity and evolutionary relationships among these diverse Homo species and populations," says Ni. "We found our long-lost sister lineage."

CAPTION

This image shows a reconstruction of Dragon Man in his habitat.

CREDIT

Chuang Zhao

Funding information for this research is available in the respective papers.

The Innovation, Shao et al.: "Geochemical provenancing and direct dating of the Harbin archaic human cranium" https://www.cell.com/the-innovation/fulltext/S2666-6758(21)00056-4 DOI: 10.1016/j.xinn.2021.100131

The Innovation, Ji et al.: "Late Middle Pleistocene Harbin cranium represents a new Homo species" https://www.cell.com/the-innovation/fulltext/S2666-6758(21)00057-6 DOI: 10.1016/j.xinn.2021.100132

The Innovation, Ni et al.: "Massive cranium from Harbin in northeastern China establishes a new Middle Pleistocene human lineage" https://www.cell.com/the-innovation/fulltext/S2666-6758(21)00055-2 DOI: 10.1016/j.xinn.2021.100130

The Innovation (@The_InnovationJ), published by Cell Press in partnership with members of the Youth Innovation Promotion Association (YIPA), a part of the Chinese Academy of Sciences, is a new broad-scope, open access journal publishing basic and applied research that impacts and benefits society. Visit https://www.cell.com/the-innovation. To receive Cell Press media alerts, contact press@cell.com.

UPDATED

Homo who? A new mystery human species has been discovered in Israel

June 24, 2021 

An international group of archaeologists have discovered a missing piece in the story of human evolution.

Excavations at the Israeli site of Nesher Ramla have recovered a skull that may represent a late-surviving example of a distinct Homo population, which lived in and around modern-day Israel from about 420,000 to 120,000 years ago

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Aerial view of the Nesher Ramla sinkhole. The site of Nesher Ramla during excavation. Yossi Zaidner

As researchers Israel Hershkovitz, Yossi Zaidner and colleagues detail in two companion studies published today in Science, this archaic human community traded both their culture and genes with nearby Homo sapiens groups for many thousands of years.
The new fossils

Pieces of a skull, including a right parietal (towards the back/side of the skull) and an almost complete mandible (jaw) were dated to 140,000–120,000 years old, with analysis finding the person it belonged to wasn’t fully H. sapiens.

The Nesher Ramla mandible and skull. Avi Levin and Ilan Theiler, Sackler / Tel Aviv University

Nor were they Neanderthal, however, which was the only other type of human thought to have been living in the region at the time.

Instead, this individual falls right smack in the middle: a unique population of Homo never before recognised by science

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Imaging of the Nesher Ramla mandible and teeth. Ariel Pokhojaev/Tel Aviv University

Through detailed comparison with many other fossil human skulls, the researchers found the parietal bone featured “archaic” traits that are substantially different from both early and recent H. sapiens. In addition, the bone is considerably thicker than those found in both Neanderthals and most early H. sapiens.

The jaw too displays archaic features, but also includes forms commonly seen in Neanderthals.

The bones together reveal a unique combination of archaic and Neanderthal features, distinct from both early H. sapiens and later Neanderthals.

Are there are more of these people?

The authors suggest fossils found at other Israeli sites, including the famous Lady of Tabun, might also be part of this new human population, in contrast to their previous Neanderthal or H. sapiens identification.

The “Lady of Tabun” (known to archaeologists as Tabun C1) was discovered in 1932 by pioneering archaeologist Yusra and her field director, Dorothy Garrod.

Extensively studied, this important specimen taught us much about Neanderthal anatomy and behaviour in a time when very little was known about our enigmatic evolutionary cousins.

Read more: Ancient teenager the first known person with parents of two different species

If Tabun C1 and others from the Qesem and Zuttiyeh Caves were indeed members of the Nasher Ramel Homo group, this reanalysis would explain some inconsistencies in their anatomy previously noted by researchers.

The mysterious Nesher Ramla Homo may even represent our most recent common ancestor with Neanderthals. Its mix of traits supports genetic evidence that early gene flow between H. sapiens and Neanderthals occurred between 400,000 and 200,000 years ago. In other words, that interbreeding between the different Homo populations was more common than previously thought.

Even more puzzling, the team also found a collection of some 6,000 stone tools at the Nesher Ramla site.
A flint scraper — one of the stone tools of Nesher Ramla Homo. Tal Rogovski

These tools were made the same way contemporaneous H. sapiens groups made their technology, with the similarity so strong it appears the two populations — Nesher Ramla Homo and H. sapiens — were hanging out on a regular basis. It seems they weren’t just exchanging genes, but also tips on tool-making.
And there was fire!

The site also produced bones of animals caught, butchered, and eaten on-site. These findings indicate Nesher Ramla Homo hunted a range of species, including tortoise, gazelle, aurochs, boar and ostrich.

Furthermore, they were using fire to cook their meals, evident through the uncovering of a campfire feature the same age as the fossils. Indeed, the Nesher Ramla Homo were not only collecting wood to make campfires and cook, but were also actively managing their fires as people do today.

Exposure of animal bones and lithic artifacts in the layer with the Nesher Ramla Homo fossils. Yossi Zaidner

While the earliest indications of controlled use of fire is much older — perhaps one million years ago - the interesting thing about this particular campfire is the evidence that Nesher Ramla people tended to it as carefully as contemporary H. sapiens and Neanderthals did their own fires.

Most impressive is that the campfire feature survived, intact, outside of a protected cave environment for so long. It is now the oldest intact campfire ever found in the open air.

In sum, if we think of the story of human evolution like an Ikea bookcase that isn’t quite coming together, this discovery is effectively like finding the missing shelf buried at the bottom of the box. The new Nesher Ramla Homo allows for a better-fitting structure, although a few mysterious “extra” pieces remain to be pondered over.

For example, exactly how did the different Homo groups interact with each other? And what does it mean for the cultural and biological changes that were occurring for Homo populations in this period?

Continuing to work with these questions (the “extra pieces”) will help us build a better understanding of our human past.


View of the deep section during excavation at Nesher Ramla, showing the deep. archaeological sequence. Yossi Zaidner

Author

Michelle Langley

Senior Research Fellow, Griffith University
Disclosure statement
Dr Michelle Langley is a Senior Research Fellow in the Australian Research Centre for Human Evolution and Lecturer in Archaeology in the School of Environment and Science at Griffith University. She receives funding from the Australian Research Council.

New fossils reveal previously unknown population of archaic hominin from the Levant

AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE

Research News

 

In two companion studies, researchers reveal a previously unknown population of archaic hominin- the "Nesher Ramla Homo" - from a recently excavated site in Israel dated to roughly 140,000 to 120,000 years ago. Analysis of both the fossils and associated artifacts from the site suggests that the group represents a last surviving population of Middle Pleistocene Homo, characterized by a distinctive combination of Neanderthal and archaic human features and technology that until only recently was linked to more modern Homo lineages. It's been assumed that Neanderthals originated and thrived on the European continent well before the arrival of modern humans. However, recent evidence suggests a genetic contribution from a yet unknown non-European group, indicating a long and dynamic history of interaction between Eurasian and African hominin populations. Here, Israel Hershkovitz, Yossi Zaidner and colleagues present fossil, artifact, and radiometric evidence from the Levant region of the Middle East that illustrates this complexity. According to Hershkovitz et al., the newly discovered Nesher Ramla Homo exhibits anatomical features that are more archaic than contemporaneous Eurasian Neanderthals and the modern humans who also lived in the Levant. The findings indicate that this archaic lineage may represent one of the last surviving populations of Middle Pleistocene Homo in southwest Asia, Africa and Europe. In the companion study, Zaidner et al. provide the archaeological context of the new fossils, reporting on the associated radiometric ages, artifact assemblages and the behavioral and environmental insights they offer. Zaidner et al. show that the Nesher Ramla Homo were well versed in technologies that were previously only known among H. sapiens and Neanderthals. Together, the findings provide archaeological support for close cultural interactions and genetic admixture between different human lineages before 120,000 years ago. This may help explain the variable expression of the dental and skeletal features of later Levantine fossils. "The interpretation of the Nesher Ramla fossils and stone tools will meet with different reactions among paleoanthropologists. Notwithstanding, the age of the Nesher Ramla material, the mismatched morphological and archaeological affinities, and the location of the site at the crossroads of Africa and Eurasia make this a major discovery," writes Marta Lahr in an accompanying Perspective.

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A new type of Homo unknown to science

Dramatic discovery in Israeli excavation

TEL-AVIV UNIVERSITY

Research News

 

IMAGE: .STATIC SKULL & MANDIBLE & PARIETAL ORTHOGRAPHIC. view more 

CREDIT: TEL AVIV UNIVERSITY

• The discovery of a new Homo group in this region, which resembles Pre-Neanderthal populations in Europe, challenges the prevailing hypothesis that Neanderthals originated from Europe, suggesting that at least some of the Neanderthals' ancestors actually came from the Levant.
• The new finding suggests that two types of Homo groups lived side by side in the Levant for more than 100,000 years (200-100,000 years ago), sharing knowledge and tool technologies: the Nesher Ramla people who lived in the region from around 400,000 years ago, and the Homo sapiens who arrived later, some 200,000 years ago.
• The new discovery also gives clues about a mystery in human evolution: How did genes of Homo sapiens penetrate the Neanderthal population that had presumably lived in Europe long before the arrival of Homo sapiens?
• The researchers claim that at least some of the later Homo fossils found previously in Israel, like those unearthed in the Skhul and Qafzeh caves, do not belong to archaic (early) Homo sapiens, but rather to groups of mixed Homo sapiens and Nesher Ramla lineage.

Nesher Ramla Homo type - a prehistoric human previously unknown to science: Researchers from Tel Aviv University and the Hebrew University of Jerusalem have identified a new type of early human at the Nesher Ramla site, dated to 140,000 to 120,000 years ago. According to the researchers, the morphology of the Nesher Ramla humans shares features with both Neanderthals (especially the teeth and jaws) and archaic Homo (specifically the skull). At the same time, this type of Homo is very unlike modern humans - displaying a completely different skull structure, no chin, and very large teeth. Following the study's findings, researchers believe that the Nesher Ramla Homo type is the 'source' population from which most humans of the Middle Pleistocene developed. In addition, they suggest that this group is the so-called 'missing' population that mated with Homo sapiens who arrived in the region around 200,000 years ago - about whom we know from a recent study on fossils found in the Misliya cave.

Two teams of researchers took part in the dramatic discovery, published in the prestigious Science journal: an anthropology team from Tel Aviv University headed by Prof. Israel Hershkovitz, Dr. Hila May and Dr. Rachel Sarig from the Sackler Faculty of Medicine and the Dan David Center for Human Evolution and Biohistory Research and the Shmunis Family Anthropology Institute, situated in the Steinhardt Museum at Tel Aviv University; and an archaeological team headed by Dr. Yossi Zaidner from the Institute of Archaeology at the Hebrew University of Jerusalem.

Timeline: The Nesher Ramla Homo type was an ancestor of both the Neanderthals in Europe and the archaic Homo populations of Asia.

Prof.Israel Hershkovitz: "The discovery of a new type of Homo" is of great scientific importance. It enables us to make new sense of previously found human fossils, add another piece to the puzzle of human evolution, and understand the migrations of humans in the old world. Even though they lived so long ago, in the late middle Pleistocene (474,000-130,000 years ago), the Nesher Ramla people can tell us a fascinating tale, revealing a great deal about their descendants' evolution and way of life."

The important human fossil was found by Dr. Zaidner of the Hebrew University during salvage excavations at the Nesher Ramla prehistoric site, in the mining area of the Nesher cement plant (owned by Len Blavatnik) near the city of Ramla. Digging down about 8 meters, the excavators found large quantities of animal bones, including horses, fallow deer and aurochs, as well as stone tools and human bones. An international team led by the researchers from Tel Aviv and Jerusalem identified the morphology of the bones as belonging to a new type of Homo, previously unknown to science. This is the first type of Homo to be defined in Israel, and according to common practice, it was named after the site where it was discovered - the Nesher Ramla Homo type.

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Fossil remains of skull and jaw.

CREDIT

Tel Aviv University

Dr. Yossi Zaidner: "This is an extraordinary discovery. We had never imagined that alongside Homo sapiens, archaic Homo roamed the area so late in human history. The archaeological finds associated with human fossils show that "Nesher Ramla Homo" possessed advanced stone-tool production technologies and most likely interacted with the local Homo sapiens". The culture, way of life, and behavior of the Nesher Ramla Homo are discussed in a companion paper also published in Science journal today.

Prof. Hershkovitz adds that the discovery of the Nesher Ramla Homo type challenges the prevailing hypothesis that the Neanderthals originated in Europe. "Before these new findings," he says, "most researchers believed the Neanderthals to be a 'European story', in which small groups of Neanderthals were forced to migrate southwards to escape the spreading glaciers, with some arriving in the Land of Israel about 70,000 years ago. The Nesher Ramla fossils make us question this theory, suggesting that the ancestors of European Neanderthals lived in the Levant as early as 400,000 years ago, repeatedly migrating westward to Europe and eastward to Asia. In fact, our findings imply that the famous Neanderthals of Western Europe are only the remnants of a much larger population that lived here in the Levant - and not the other way around."

According to Dr. Hila May, despite the absence of DNA in these fossils, the findings from Nesher Ramla offer a solution to a great mystery in the evolution of Homo: How did genes of Homo sapiens penetrate the Neanderthal population that presumably lived in Europe long before the arrival of Homo sapiens? Geneticists who studied the DNA of European Neanderthals have previously suggested the existence of a Neanderthal-like population which they called the 'missing population' or the 'X population' that had mated with Homo sapiens more than 200,000 years ago. In the anthropological paper now published in Science, the researchers suggest that the Nesher Ramla Homo type might represent this population, heretofore missing from the record of human fossils. Moreover, the researchers propose that the humans from Nesher Ramla are not the only ones of their kind discovered in the region, and that some human fossils found previously in Israel, which have baffled anthropologists for years - like the fossils from the Tabun cave (160,000 years ago), Zuttiyeh cave (250,000), and Qesem cave (400,000) - belong to the same new human group now called the Nesher Ramla Homo type.

"People think in paradigms," says Dr. Rachel Sarig. "That's why efforts have been made to ascribe these fossils to known human groups like Homo sapiens, Homo erectus, Homo heidelbergensis or the Neanderthals. But now we say: No. This is a group in itself, with distinct features and characteristics. At a later stage small groups of the Nesher Ramla Homo type migrated to Europe - where they evolved into the 'classic' Neanderthals that we are familiar with, and also to Asia, where they became archaic populations with Neanderthal-like features. As a crossroads between Africa, Europe and Asia, the Land of Israel served as a melting pot where different human populations mixed with one another, to later spread throughout the Old World. The discovery from the Nesher Ramla site writes a new and fascinating chapter in the story of humankind."

Prof. Gerhard Weber, an associate from Vienna University, argues that the story of Neanderthal evolution will be told differently after this discovery: "Europe was not the exclusive refugium of Neanderthals from where they occasionally diffused into West Asia. We think that there was much more lateral exchange in Eurasia, and that the Levant is geographically a crucial starting point, or at a least bridgehead, for this process."

CAPTION

(Left to Right): Israel Hershkovitz, Marion Prevost, Hila May, Rachel Sarig and Yossi Zaidner

CREDIT

Tel Aviv University 

Link to the research video:

https://www.youtube.com/watch?v=OGPKRuyd-5M

Link to the research video:

https://www.youtube.com/watch?v=OGPKRuyd-5M

Static skull & mandible & parietal orthographic (also attached as a PNG file):

New fossil discovery from Israel points to complicated evolutionary process

BINGHAMTON UNIVERSITY

Research News

IMAGE: THE NESHER RAMLA HUMAN MANDIBLE (LEFT) AND PARIETAL BONE (RIGHT). view more 

CREDIT: AVI LEVIN AND ILAN THEILER, SACKLER FACULTY OF MEDICINE, TEL AVIV UNIVERSITY

BINGHAMTON, N.Y. -- Analysis of recently discovered fossils found in Israel suggest that interactions between different human species were more complex than previously believed, according to a team of researchers including Binghamton University anthropology professor Rolf Quam.

The research team, led by Israel Hershkovitz from Tel Aviv University, published their findings in Science, describing recently discovered fossils from the site of Nesher Ramla in Israel. The Nesher Ramla site dates to about 120,000-140,000 years ago, towards the very end of the Middle Pleistocene time period.

The human fossils were found by Dr. Zaidner of the Hebrew University during salvage excavations at the Nesher Ramla prehistoric site, near the city of Ramla. Digging down about 8 meters, the excavators found large quantities of animal bones, including horses, fallow deer and aurochs, as well as stone tools and human bones. The human fossils consist of a partial cranial vault and a mandible. Researchers made virtual reconstructions of the fossils to analyze them using sophisticated computer software programs and to compare them with other fossils from Europe, Africa and Asia. The results suggest that the Nesher Ramla fossils represent late survivors of a population of humans who lived in the Middle East during the Middle Pleistocene period.

"The oldest fossils that show Neandertal features are found in Wesern Europe, so researchers generally believe the Neandertals originated there," said Quam. "However, migrations of different species from the Middle East into Europe may have provided genetic contributions to the Neandertal gene pool during the course of their evolution."

The finds from Nesher Ramla are noteworthy because they sample a time period in the Middle East with few fossils, so they are important additions to the growing fossil record from the region. Other fossils from this approximate time period are difficult to classify taxonomically since they seem to show a combination of features seen in both Neandertals and modern humans. The Nesher Ramla fossils seem more Neandertal-like in the mandible and less Neandertal-like in the cranial vault, but are clearly distinct from modern humans. This pattern matches what has been suggested for both Neandertals and modern humans, where the diagnostic skeletal features of each species appear first in the facial region and later on the cranial vault.

Describing the significance of the find, Dr. Hershkovitz said: "It enables us to make new sense of previously found human fossils, add another piece to the puzzle of human evolution, and understand the migrations of humans in the old world. Even though they lived so long ago, in the late middle Pleistocene, the Nesher Ramla people can tell us a fascinating tale, revealing a great deal about their descendants' evolution and way of life."

CAPTION

Transparent view of the mandibular body and tooth roots in the Nesher Ramla mandible

CREDIT

Ariel Pokhojaev, Sackler Faculty of Medicine, Tel Aviv University

The researchers were careful not to attribute the Nesher Ramla fossils to a new species. Rather, they grouped them together with earlier fossils from several sites in the Middle East that have been difficult to classify and considered all of them to represent a local population of humans that occupied the region between about 420,000-120,000. Given the fact that the Middle East sits at the crossroads of three continents, it is likely that different human groups moved into and out of the region regularly, exchanging genes with the local inhabitants. This scenario might explain the variable anatomical features in these fossils, with the Nesher Ramla fossils representing the latest known survivors of this localized Middle Pleistocene population.

"This is a complicated story, but what we are learning is that the interactions between different human species in the past were much more convoluted than we had previously appreciated," said Quam.

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The study, "A Middle Pleistocene Homo from Nesher Ramla, Israel," was published in Science, along with a companion paper discussing the culture, way of life, and behavior of the Nesher Ramla Homo.

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Virtual reconstruction of the Nesher Ramla mandible and molar.

CREDIT

: Ariel Pokhojaev, Sackler Faculty of Medicine, Tel Aviv University

Embryologists reveal a secret of a worm with regeneration super abilities

Biologists at St Petersburg University have studied mechanisms of regeneration of marine animals and found out what plays the key role in regeneration of tissues of Alitta virens

ST. PETERSBURG STATE UNIVERSITY

VIDEO: ALITTA VIRENS (FEMALE) SPAWNING view more 

CREDIT: SPBU

This worm that lives in the White Sea is able to restore lost body segments. However, it turned out that suppression of FGF protein activity disturbs this ability. Similar proteins are found in humans. This discovery may lead to developing methods of fast wound healing. The research findings are published in the journal Genes as part of the project supported by the Russian Science Foundation.

Fibroblast growth factors (FGF) are proteins that play an important role in wound healing and tissue growth. When the need for regeneration of damaged body parts occur, FGFs are produced by epidermis, nervous tissue, macrophages and fibroblasts, which are the main cells of connective tissue. As a result, the process of active cell division and the production of tropocollagen (the structural unit of a collagen fibre) is triggered; the intercellular matrix and the main substance of the connective tissue are synthesised; and the growth of nerves and blood vessels begins.

'Proteins of the FGF group are currently used in experimental methods of cell culture. They are added to the cocktail of nutritious medium in order to grow various cell cultures of animal origin. However, we can go beyond cell culture, for example, we can use them in fast wound treatment medicine', explains Vitaly Kozin, Head of the project, Assistant Professor at St Petersburg University.

CAPTION

Alitta virens

CREDIT

SPbU

Embryologists of St Petersburg University studied FGF of Alitta virens. This annelids live in the White Sea. They are the largest annelids (up to half a metre long) and thanks to their unusual colour they are look very impressive. They are extremely fecund, live long (three to seven years) and are able to grow lost body parts. Also, one can catch them with a scoop net: during spawning that happens at the end of June - beginning of July, when the animals swarm near the water surface. This is how the researchers gathered them. After that they fertilised them artificially in a laboratory and grew new individuals in controlled environment that were suitable for research.

First, the embryologists studied bioinformatics data base where they found the genes they were interested in. Then they described the structure and origins of the genes in order to compare them with the part of DNA which play the similar role in humans. Alitta virens has only two ligands (molecules that bind to cell surface thereby transmitting the signal) and two FGF receptors, which is much less than in humans. Then the scientists extracted these genes products from Alitta virens that were regenerating after damage, and cloned their fragments. They synthesised detectable probes that made it possible to see where exactly these genes work in worms. The method is called hybridisation in situ, which means RNA sticking inside the body.

When the time and the place of gene activity was identified, the scientists artificially blocked receptors and intermediates of FGF signalling pathway by adding inhibitors SU5402 and U0126 into sea water where the worms lived. The process was monitored using antibodies with a special colour, fluorescent dyes and impulse laballing of DNA precursors. It turned out that blocking of FGF affected not only the process of cell division in the damaged part of the body, but also the regeneration process in general. The control animals (those that did not receive inhibitors) started cell division in four hours after amputation and regeneration of muscles and nerves was observed for six days, whereas, inhibitors stopped regeneration completely.

CAPTION

Photographs of the White Sea during collecting of the material (Alexandra Shalaeva and Vitaly Kozin)

CREDIT

Vitaly Kozin

'We managed to study the mechanism of regeneration of the tissues in Alitta virens. This knowledge can be used for therapeutic approaches in regenerative medicine. The study showed that the principal role of FGF in vertebrates and invertebrates does not differ. The analysis showed that participation of FGF in regenerating processes must have existed in a common ancestor of animals with bilateral symmetry that lived 500 million years ago. We are still to find out what was the reason for slowing of regeneration in humans. This summer we will test synthesised fibroblast growth factor on Alitta virens. Perhaps, its increased level in comparison with a natural one will lead to speeding up regeneration. Also, we need to find out how damaging of tissues activates FGF and what other parts of genome comply with its signals', said Vitaly Kozin.

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Cosmic dawn, when stars formed for the first time, occurred 250 million to 350 million years after the beginning of the universe

 VIDEO: THE VIDEO SHOWS THE FORMATION AND EVOLUTION OF THE FIRST STARS AND GALAXIES IN A VIRTUAL UNIVERSE SIMILAR TO OUR OWN. THE SIMULATION BEGINS JUST BEFORE COSMIC DAWN, WHEN THE... view more 

CREDIT: CREDIT: DR HARLEY KATZ, BEECROFT FELLOW, DEPARTMENT OF PHYSICS, UNIVERSITY OF OXFORD

Cosmic dawn, when stars formed for the first time, occurred 250 million to 350 million years after the beginning of the universe, according to a new study led by researchers at University College London (UCL) and the University of Cambridge.

The study, published in the Monthly Notices of the Royal Astronomical Society, suggests that the NASA James Webb Space Telescope (JWST), scheduled to launch in November, will be sensitive enough to observe the birth of galaxies directly.

The UK-led research team examined six of the most distant galaxies currently known, whose light has taken most of the universe's lifetime to reach us. They found that the distance of these galaxies away from Earth corresponded to a "look back" time of more than 13 billion years ago, when the universe was only 550 million years old.

Analysing images from the Hubble and Spitzer Space Telescopes, the researchers calculated the age of these galaxies as ranging from 200 to 300 million years, allowing an estimate of when their stars first formed.

Lead author Dr Nicolas Laporte (University of Cambridge), who started the project while at UCL, said: "Theorists speculate that the universe was a dark place for the first few hundred million years, before the first stars and galaxies formed.

"Witnessing the moment when the universe was first bathed in starlight is a major quest in astronomy.

"Our observations indicate that cosmic dawn occurred between 250 and 350 million years after the beginning of the universe, and, at the time of their formation, galaxies such as the ones we studied would have been sufficiently luminous to be seen with the James Webb Space Telescope."

The researchers analysed starlight from the galaxies as recorded by the Hubble and Spitzer Space Telescopes, examining a marker in their energy distribution indicative of the presence of atomic hydrogen* in their stellar atmospheres. This provides an estimate of the age of the stars they contain.

This hydrogen signature increases in strength as the stellar population ages but diminishes when the galaxy is older than a billion years. The age-dependence arises because the more massive stars that contribute to this signal burn their nuclear fuel more rapidly and therefore die first.

Co-author Dr Romain Meyer (UCL Physics & Astronomy and the Max Planck Institute for Astronomy in Heidelberg, Germany) said: "This age indicator is used to date stars in our own neighbourhood in the Milky Way but it can also be used to date extremely remote galaxies, seen at a very early period of the universe.

"Using this indicator we can infer that, even at these early times, our galaxies are between 200 and 300 million years old."

In analysing the data from Hubble and Spitzer, the researchers needed to estimate the "redshift" of each galaxy which indicates their cosmological distance and hence the look-back time at which they are being observed. To achieve this, they undertook spectroscopic measurements using the full armoury of powerful ground-based telescopes - the Chilean Atacama Large Millimetre Array (ALMA), the European Very Large Telescope, the twin Keck telescopes in Hawaii, and Gemini-South telescope.

These measurements enabled the team to confirm that looking at these galaxies corresponded to looking back to a time when the universe was 550 million years old.

Co-author Professor Richard Ellis (UCL Physics & Astronomy), who has tracked ever more distant galaxies over his career, said: "Over the last decade, astronomers have pushed back the frontiers of what we can observe to a time when the universe was only 4% of its present age. However, due to the limited transparency of Earth's atmosphere and the capabilities of the Hubble and Spitzer Space Telescopes, we have reached our limit.

"We now eagerly await the launch of the James Webb Space Telescope, which we believe has the capability to directly witness cosmic dawn.

"The quest to see this important moment in the universe's history has been a holy grail in astronomy for decades. Since we are made of material processed in stars, this is in some sense the search for our own origins."**

The new study involved astronomers at the University of California-Santa Cruz, the University of California, and the University of Texas.

The researchers received support from the Kavli Foundation, the European Research Council, the National Aeronautics and Space Administration (NASA), and the National Science Foundation (NSF) in the United States.

The NASA-led James Webb Space Telescope, the successor to the Hubble observatory, is scheduled to be launched into space in November. It will be the premier observatory over the next decade, serving thousands of astronomers worldwide. It consists of an infrared observatory, an immense mirror 6.5 metres wide, and a diamond-shaped sunshield. UCL scientists at the Mullard Space Science Laboratory have built and tested key hardware components for the NIRSpec (Near-Infrared Spectrograph), one of the telescope's four instruments.

*Atomic hydrogen is hydrogen that has not been split into protons and electrons.

**All the heavier elements in the universe - everything except for hydrogen, helium and lithium - are synthesised in stars and then seeded across the universe when the stars explode at the end of their lives. This includes the elements that make up humans - the calcium in our bones, the iron in our blood.

CAPTION

Colour image of the galaxy cluster used to detect one of the six galaxies, MACS0416-JD, examined in a study led by researchers at University College London and the University of Cambridge. This galaxy has an estimated age of 351 million years, which means that this galaxy was formed 178 million years after the Big Bang. The stellar mass of this galaxy is one billion times the mass of the Sun. This object is currently the most distant galaxy detected with ALMA.

CREDIT

Credit: ESA/Hubble, NASA, HST Frontier Fields