The researchers note that hemimastigotes have been known to scientists since the 19th century, but it was not until very recently that technology has allowed scientists to learn how different they are from other eukaryotic life forms. The researchers report that one of their team members, Yana Eglit, had been digging in a local park just outside of Halifax. Intrigued by the microbes she found in the dirt, she isolated a group that appeared to be hemimastigotes. After letting the microbes reproduce in a small dish filled with nothing but dirt and water for a month, she collected samples that the team used to conduct a genetic analysis.

The researchers report that the hemimastigotes are so different from anything observed before that fungi and animals are actually more closely related. They describe the microbes as being approximately two-hundredths of a millimeter long—they move using over a dozen flagella. And they survive by eating other microbes. It was the latter characteristic that led the team to name the species Hemimastix kukwesjijk, in honor of a hairy man-eating ogre from Mi'kmaq (native people in Nova Scotia) folklore.

The researchers describe hemimastigotes as representing a major new branch on the evolutionary tree—standing above the level of a kingdom. The team was able to analyze hundreds of samples, thanks to Eglit's efforts in getting them to reproduce, which provided a very clear understanding of the genetic makeup of the microbes. They also suggest their findings fill some evolutionary holes in the tree of life. They also note that in addition to learning about how different hemimastigotes truly are from other life forms, the work by Eglit also offers a lesson for other researchers in how to grow such species in large enough volume to allow for such thorough study.

More information: Gordon Lax et al. Hemimastigophora is a novel supra-kingdom-level lineage of eukaryotes, Nature (2018). DOI: 10.1038/s41586-018-0708-8 </s> Canadian researchers have discovered a new kind of organism that's so different from other living things that it doesn't fit into the plant kingdom, the animal kingdom, or any other kingdom used to classify known organisms.Two species of the microscopic organisms, called hemimastigotes, wereby Dalhousie University graduate student Yana Eglit.A genetic analysis shows they're more different from other organisms than animals and fungi (which are in different kingdoms) are from each other, representing a completely new part of the tree of life, Eglit and her colleagues report this week in the journal Nature "They represent a major branch... that we didn't know we were missing," said Dalhousie biology professor Alastair Simpson, Eglit's supervisor and co-author of the new study.In fact, he estimatesThe hemimastigotes analyzed by the Dalhousie team were found by Eglit during a spring hike with some other students along the Bluff Wilderness Trail outside Halifax a couple of years ago. She often has empty sample vials in her pockets or bags, and scooped a few tablespoons of dirt into one of them from the side of the trail.Back at the lab, she soaked the dirt in water, which often revives microbes that have gone dormant, waiting for the next big rainstorm. Over the next few weeks, she checked on the dish through a microscope to see what might be swimming around.Then, one day, about three weeks later, she saw something that caught her eye - something shaped like the partially opened shell of a pistachio. It had lots of hairs, called flagella, sticking out."It's as if these cells never really learned that they have many flagella," Eglit said with a laugh. She had seen something with that strange motion once before, a few years ago, and recognized it as a rare hemimastigote.But at that time, no one could figure out how they fit into the evolutionary tree of life. Consequently, they've been "a tantalizing mystery" to microbiologists for quite a long time, Eglit said.About 10 species of hemimastigotes have been described over more than 100 years. Butto see how they were related to other living things.Realizing that she had something very rare and special, Eglit flagged another graduate student Gordon Lax, who specializes in genetic analyses of individual microbes - a new and tricky technique - to see where they fit in the evolutionary tree. The pair dropped everything to analyze the new microbe.Eglit wanted to see if she could find more of the creatures in the dish, and, as she was looking, she spotted another kind of hemimastigote."To our tremendous surprise, two of these extremely rarely seen organisms ended up in one dish."The researchers named it Hemimastix kukwesjijk after Kukwes, a greedy, hairy ogre from the mythology of the local Mi'kmaq people. (The suffix "jijk" means "little.")Eglit watched carefully as it hunted." Eglit said.: "We were able to domesticate it, in a way."That means scientists can now give captive specimens to other scientists to study, and their rarity is not the issue it was before.Based on the genetic analysis they've done so far, the Dalhousie team has determined that hemimastigotes are unique and different enough from other organisms to form their own "supra-kingdom" - a grouping so big that animals and fungi, which have their own kingdoms, are considered similar enough to be part of the same supra-kingdom.They are now doing a more complete genetic analysis of Hemimastix. That's expected to turn up new data that will help scientists piece together the evolutionary history of life on Earth with more detail and more accuracy.Eglit says it's "extremely exciting" that it's still possible to discover something so different from all known life on Earth."It really shows how much more there is out there."But Simpson noted that discoveries like this one are pretty rare: "It'll be the one time in my lifetime that we find this sort of thing."Biology professor Alastair Simpson tells Mainstreet host Bob Murphy how a microbe found in a dirt sample from the Bluff Wilderness Hiking Trail near Halifax led to the discovery of a previously unknown branch in the evolutionary 'Tree Of Life.' The research has just been published in the journal Nature. </s> Canadian researchers have discovered a new kind of organism that's so different from other living things that it doesn't fit into the plant kingdom, the animal kingdom, or any other kingdom used to classify known organisms.

Two species of the microscopic organisms, called hemimastigotes, were found in dirt collected on a whim during a hike in Nova Scotia by Dalhousie University graduate student Yana Eglit.

A genetic analysis shows they're more different from other organisms than animals and fungi (which are in different kingdoms) are from each other, representing a completely new part of the tree of life, Eglit and her colleagues report this week in the journal Nature.

"They represent a major branch… that we didn't know we were missing," said Dalhousie biology professor Alastair Simpson, Eglit's supervisor and co-author of the new study.

"There's nothing we know that's closely related to them."

In fact, he estimates you'd have to go back a billion years — about 500 million years before the first animals arose — before you could find a common ancestor of hemimastigotes and any other known living things.

This is the part of the Bluff Wilderness Trail in Nova Scotia where graduate student Yana Eglit collected some dirt that ended up containing two species of rare hemimastigotes. (Submitted by Yana Eglit)

The hemimastigotes analyzed by the Dalhousie team were found by Eglit during a spring hike with some other students along the Bluff Wilderness Trail outside Halifax a couple of years ago. She often has empty sample vials in her pockets or bags, and scooped a few tablespoons of dirt into one of them from the side of the trail.

Back at the lab, she soaked the soil in water, which often revives microbes that have gone dormant, waiting for the next big rainstorm. Over the next few weeks, she checked on the dish through a microscope to see what might be swimming around.

Strange movements

Then, one day, about three weeks later, she saw something that caught her eye — something shaped like the partially opened shell of a pistachio. It had lots of hairs, called flagella, sticking out. Most known microbes with lots of flagella move them in co-ordinated waves, but not this one, which waved them in a more random fashion.

"It's as if these cells never really learned that they have many flagella," Eglit said with a laugh. She had seen something with that strange motion once before, a few years ago, and recognized it as a rare hemimastigote.

Hemimastigotes were first seen and described in the 19th century. But at that time, no one could figure out how they fit into the evolutionary tree of life. Consequently, they've been "a tantalizing mystery" to microbiologists for quite a long time, Eglit said.

Light microscopes show the two hemimastigotes, Spironema, left, and Hemimastix kukwesjijk, found in the same dish. (Yana Eglit/Nature)

Like animals, plants, fungi and amoebas — but unlike bacteria — hemimastigotes have complex cells that have mini-organs called organelles including a nucleus that holds chromosomes of DNA, making them part of the "domain" of organisms called eukaryotes rather than bacteria or archaea.

About 10 species of hemimastigotes have been described over more than 100 years. But up until now, no one had been able to do a genetic analysis to see how they were related to other living things.

Realizing that she had something very rare and special, Eglit flagged another graduate student Gordon Lax, who specializes in genetic analyses of individual microbes — a new and tricky technique — to see where they fit in the evolutionary tree. The pair dropped everything to analyze the new microbe.

The co-authors of the new study include, left to right, Dalhousie University postdoctoral researcher Laura Eme, Eglit and fellow graduate student Gordon Lax. (Michelle Léger)

New species

Eglit wanted to see if she could find more of the creatures in the dish, and, as she was looking, she spotted another kind of hemimastigote.

"To our tremendous surprise, two of these extremely rarely seen organisms ended up in one dish."

There were more of the second kind, which turned out to be a new species.

The researchers named it Hemimastix kukwesjijk after Kukwes, a greedy, hairy ogre from the mythology of the local Mi'kmaq people. (The suffix "jijk" means "little.")

Eglit watched carefully as it hunted. Hemimastix shoots little harpoons called extrusomes to attack prey such as Spumella, a relative of aquatic microbes called diatoms. It grasps its prey by curling its flagella around it, bringing it to a "mouth" on one end of the cell called a capitulum "as it presumably sucks its cytoplasm out," Eglit said.

Hemimastix kukwesjijk feeds on its prey in this microscope image. It attacks the prey with harpoon-like organs, then uses its flagella to bring the prey to its mouth, called a capitulum, and sucks out the juices or cytoplasm. (Yana Eglit/Nature)

Once she knew what it ate, she reared its prey in captivity so she could also feed and breed captive Hemimastix: "We were able to domesticate it, in a way."

That means scientists can now give captive specimens to other scientists to study, and their rarity is not the issue it was before.

Based on the genetic analysis they've done so far, the Dalhousie team has determined that hemimastigotes are unique and different enough from other organisms to form their own "supra-kingdom" — a grouping so big that animals and fungi, which have their own kingdoms, are considered similar enough to be part of the same supra-kingdom.

They are now doing a more complete genetic analysis of Hemimastix. That's expected to turn up new data that will help scientists piece together the evolutionary history of life on Earth with more detail and more accuracy.

Eglit says it's "extremely exciting" that it's still possible to discover something so different from all known life on Earth.

"It really shows how much more there is out there."

But Simpson noted that discoveries like this one are pretty rare: "It'll be the one time in my lifetime that we find this sort of thing." </s> In the wake of the first gene-edited embryos in the US being created earlier this year, Chinese researchers have employed a different technique to swap a single base in a human embryo's genome.

The precise edit was designed to return functionality to a gene responsible for a component of haemoglobin, which in its mutated form results in an often fatal blood condition called beta-thalassaemia.

A team of researchers from Sun Yat-sen University in Guangzhou, China, used what's called a base editor technique to change a single G back to an A in the DNA code of an embryonic cell's HBB gene.

The change might have been tiny, but in its mutated form HBB can't produce the protein beta-globin needed to build the oxygen-carrying haemoglobin for our red blood cells.

A shortage of haemoglobin means a shortage of oxygen, impeding growth and development and leading to a lifetime of blood transfusions to treat anaemia – if the embryo survives at all.

Beta-thalassaemia is usually a recessive condition, meaning both parents need to contribute a copy of the mutated gene for anaemia to develop in their child.

Correcting the mutations in this gene could help parents carry an embryo to term, or remove the trait from family lines.

About 400 different kinds of code-corruptions can affect HBB.

In this case, the researchers focussed on a single point-mutation that targets a base called cytosine (C) and exchanges it for one called thymine (T).

Each of these letters complements the other two kinds of base – thymine is a jigsaw-puzzle piece that matches adenine (A), while cytosine matches guanine (G).

By swapping a C for a T, the mutation should revert back to the proper 'A' code.

If this base editing technology seems unnecessarily complicated, there's a good reason for doing a genetic do-si-do – it means the strand of DNA isn't being snipped all the way through.

To test if the procedure was feasible, the team created a cell line with pieces of the gene embedded inside and then used two different base editing techniques to change the code.

Satisfied the editing could be done, they took the process to the next level and edited the gene in skin cells from a beta-thalassemia patient.

Researchers transferred the nucleus of the patient's skin cells into 30 mature oocytes – or human egg cells.

One of the techniques was then applied to the 26 cells that survived the cloning procedure, which successfully turned the G to an A in 9 of the embryos, and a G to a C (cytosine) in one.

None of the embryos were developed further or implanted.

Gene editing has been big news in recent years with advances in the application of a technology called CRISPR, which uses enzymes found in bacteria to chew up DNA at a specific location.

Applying this kind of corrective genetic surgery to human embryos could spell an end to a variety of inherited conditions, but so far efforts have been controversial, to say the least.

Questions have developed recently on whether or not the technology produces unwanted mutations, indicating that for all of its promise, it's still early days for this revolutionary engineering tool.

Base editing won't replace CRISPR, but could be a more delicate solution for those solitary mutations.

"We are the first to demonstrate the feasibility of curing genetic disease in human embryos by base editor system," researcher Junjiu Huang told the BBC.

Feasibility is the word here. We're nowhere near a safe operating procedure for repairing genes we consider broken in embryos.

But each careful step, coupled with healthy public debate, brings us a bit closer to an age when debilitating conditions like beta-thalassemia will be notes in a medical history book.

This research was published in Protein & Cell. </s> Scientists have cured human embryos of a blood disorder in a first-ever technique that could one day stamp out inherited diseases.

Researchers with Sun Yat-sen University in China performed “chemical surgery” on the lab-made embryos to remove the disease called beta thalassemia, which reduces the production of hemoglobin, according to the BBC.

“We are the first to demonstrate the feasibility of curing genetic disease in human embryos by base editor system,” said researcher Junjiu Huang.

Huang said the study creates the possibility of treating patients and preventing babies being born with beta thalassemia — “and even other inherited diseases.”

The experiment was conducted on tissue taken from a patient with the blood disorder and human embryos made through cloning.

Researchers used a technique called “base editing,” which alters the fundamental building blocks of DNA — adenine, cytosine, guanine and thymine, commonly known by their respective first letters, A, C, G and T.

Beta thalassemia is caused by a fault called a point mutation — a change to a single base in the genetic code.

Researchers used base editing to change a G base to an A — successfully curing the DNA of the blood disorder.

Base editing is an advanced form of gene editing called Crispr, which breaks DNA.

David Liu, who pioneered the technique at Harvard University, said the method is preferred because it creates fewer side effects than Crispr.

“About two-thirds of known human genetic variants associated with disease are point mutations,” said Liu. “So base editing has the potential to directly correct, or reproduce for research purposes, many pathogenic [mutations].” </s> (CNN) Scientists are getting one step closer to snipping inherited genetic diseases out of human offspring using a gene-editing technique called CRISPR.

For the first time, scientists said, they corrected a gene mutation linked to inherited heart conditions in human embryos using the approach. A study demonstrating the technique was published in the journal Nature on Wednesday (PDF).

Last week, the MIT Technology Review released the first news of this scientific feat, describing the research as the first-known attempt at creating genetically modified human embryos in the United States.

However, Juan Carlos Izpisua Belmonte, a co-author of the study, described it as the first in the world to demonstrate gene-editing to be safe, accurate and efficient in correcting a pathogenic gene mutation in human embryos. Previous attempts by Chinese researchers were unsuccessful at achieving this without safety concerns.

"This is the first that has been demonstrated as safe and working," said Belmonte, a professor at the Salk Institute for Biological Studies' gene expression laboratory in La Jolla, California.

"All cells of the embryo were corrected," he said. "It seems to be working from these samples that we have chosen, but we need to do much more basic research with many other genes."

The study was a collaboration between the Salk Institute, the Oregon Health & Science University in Portland and Korea's Institute for Basic Science.

Scientists estimate that more than 10,000 human diseases may result from mutations to a single gene occurring in all cells of the body, according to the World Health Organization

Cutting and correcting gene mutations

The study used 75 human zygotes in which the father carried a mutation on the MYBPC3 gene, Belmonte said. The eggs used to produce the zygotes did not carry that gene mutation. The researchers noted that they received informed consent from the donors of the eggs, sperm and embryos used in the study.

Hypertrophic cardiomyopathy also is thought to be the most common inherited or genetic heart disease in the US, according to the Centers for Disease Control and Prevention

Newly fertilized eggs before gene editing, left, and embryos after gene editing and a few rounds of cell division.

In a lab dish, the researchers used CRISPR, a gene-editing technique, to remove the harmful MYBPC3 mutation from the human zygotes. Then, the zygotes' own DNA-repair mechanism replaced what was cut out with a copy of a MYBPC3 gene from the mother, which did not carry a mutation, Belmonte said.

"A male research subject known to be heterozygous for this gene mutation was recruited for the study, as were several healthy young egg donors," Dr. Paula Amato, an obstetrician-gynecologist at Oregon Health & Science University, said Tuesday. She was a co-author of the study.

"CRISPR was introduced at the time of sperm injection," she said. "Then, DNA repair of the embryos was assessed."

The researchers found that about 72% of zygotes were properly and safely corrected on the MYBPC3 gene, Belmonte said.

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This method significantly differed from studies in which scientists used the CRISPR tool to replace what was cut out with whatever the scientists desired.

"The previous human studies done in China had very small numbers, and one of them used abnormal embryos," Amato said. "So we think this is the first, largest study from which you could draw some reasonable conclusions."

Some gene-editing attempts in human embryos have been problematic, resulting in an issue called mosaicism , in which the corrections made in one gene failed to replicate once that cell divided into two cells, those two cells divided into four cells and so on.

"So when the baby is born, all the cells do not have the mutation anymore. ... This study, it shows that we can correct the embryo and then, after the division, all the cells are corrected, so there's not what we call mosaicism," said Belmonte, who is also a member of the National Academies of Sciences, Engineering and Medicine's committee on human gene editing.

This year, the academies published a report on human genome editing that addressed potential applications of the technology, including the possible prevention or treatment of inherited diseases or conditions.

The future of gene editing

Though the researchers have expressed enthusiasm around their new study, they also noted that the findings must be replicated in followup research before this gene-editing approach can move forward to clinical trials.

"The fact that it is, apparently, a new and poorly understood mechanism and it is not the now standard CRISPR 'cut and replace' method adds to the time needed for research into its safety and effectiveness," said Hank Greely, professor of law and genetics at Stanford University, who was not involved in the new study.

Yet future research can come with some political challenges, Amato said.

"First of all, there are regulations regarding use of federal funds for embryo research, so the (US National Institutes of Health) does not currently support embryo research, so that's one barrier. The other barrier is, the (US Food and Drug Administration) is prohibited from considering any clinical trials related to germline genetic modification," she said.

In this new study the embryos were only allowed to mature to day three after fertilization before they were disaggregated, or isolated into various components, for further analysis.

In the far-off future, a clinical trial could include transplanting corrected embryos into a uterus with the goal of establishing pregnancy and then monitoring the embryos as they develop into children.

Still, "it is way too early to contemplate implanting the edited embryos for the purpose of actually establishing a pregnancy," said Dana Carroll, a professor of biochemistry at the University of Utah who was not involved in the new study but has used CRISPR in his own research.

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"The genome editing tools are currently not sufficiently efficient and specific to be reliable, and regulatory and oversight processes have not been established," Carroll said, adding that the work on the new study was "well-done" and "well-presented."

"The authors have made an important discovery regarding the repair of CRISPR-induced DNA breaks in human eggs just at the time of fertilization," he said.

"This information will help to guide ongoing research, and it demonstrates that research on early-stage human embryos will be necessary to establish safe and effective procedures in the long run," he said. "There is still a lot of work to do to understand repair processes in very early embryos and to optimize the use of the CRISPR reagents, but this study makes a valuable contribution."

Some CRISPR critics have argued that gene editing may give way to eugenics and to allowing embryos to be edited with certain features in order to develop so-called designer babies

However, the researchers wrote in their study that they hope CRISPR could be considered as an alternative option to preimplantation genetic diagnosis, also known as PGD, for couples at risk of passing on an inherited disease.

'This opens up the possibility for those embryos'

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When only one parent carries a heterozygous mutation on a gene, about half of the embryos from that parent should be mutation-free while the others would have the mutation. Selectively, the parents' doctor would chose the healthy embryos to be implanted and discard the embryos with the mutations, Belmonte said.

Sometimes, "a couple that wants to have a baby and they have a mutation, they may not have enough embryos to choose from," he said. This is when CRISPR can come in.

"This technology, independent of the embryos that are there, it would go on and correct all of them. ... This opens up the possibility for those embryos," he said. "That's important because after the first implantation, if it doesn't work, you can do it again."

The researchers wrote in their study, "PGD may be a viable option for heterozygous couples at risk of producing affected offspring. In cases when only one parent carries a heterozygous mutation, 50% of embryos should be mutant. In contrast, targeted gene correction can potentially rescue a substantial portion of mutant human embryos, thus increasing the number of embryos available for transfer."

Nonetheless, using CRISPR in that way remains a long way off.

Join the conversation See the latest news and share your comments with CNN Health on Facebook and Twitter.

Shoukhrat Mitalipov, director of the Oregon Health & Science University's Center for Embryonic Cell and Gene Therapy, helped lead the new study. In 2013, Mitalipov and his colleagues reported the first success in cloning human stem cells , reprogramming human skin cells back to their embryonic state. In 2007, a research team led by Mitalipov announced that they created the first cloned monkey embryo and extracted stem cells from it.

Now, when it comes to using CRISPR to correct gene mutations in embryos, Mitalipov said Tuesday, "We've done some ground work. ... There is still a long road ahead, and it's unclear at this point when we will be allowed to move on." </s> Image copyright Emery Smith Image caption The genome study uncovers possible reasons for the skeleton's unusual features

Tests on a six-inch-long mummified skeleton from Chile confirm that it represents the remains of a newborn with multiple mutations in key genes.

Despite being the size of a foetus, initial tests had suggested the bones were of a child aged six to eight.

These highly unusual features prompted wild speculation about its origin.

Now, DNA testing indicates that the estimated age of the bones and other anomalies may have been a result of the genetic mutations.

Details of the work have been published in the journal Genome Research.

In addition to its exceptionally small height, the skeleton had several unusual physical features, such as fewer than expected ribs and a cone-shaped head.

The remains were initially discovered in a pouch in the abandoned nitrate mining town of La Noria. From there, they found their way into a private collection in Spain.

Some wondered whether the remains, dubbed Ata after the Atacama region where they were discovered, could in fact be the remains of a non-human primate. A documentary, called Sirius, even suggested it could be evidence of alien visitations.

Genetic investigation

The new research puts those ideas to rest.

A scientific team analysed the individual's genome - the genetic blueprint for a human, contained in the nucleus of cells.

They had already used this to confirm that the individual was human. Now, the team has presented evidence that Ata was a female newborn with multiple mutations in genes associated with dwarfism, scoliosis and abnormalities in the muscles and skeleton.

"What was striking and caused us to speculate early on that there was something strange about the bones was the apparent maturity of the bones (density and shape)," said Garry Nolan, a professor of microbiology and immunology at the Stanford University School of Medicine in California.

He told BBC News: "There was proportionate maturation of the bones, making the body look more mature despite the fact that the specimen was itself small. This discrepancy drove much of the research. So, we believe that one or more of the mutated genes was responsible for this."

The results revealed four new single nucleotide variants (SNVs) - a type of genetic mutation - in genes that were known to cause bone diseases, like scoliosis or dislocations, as well as two more SNVs in genes involved in producing collagen.

Ata also had 10 pairs of ribs, rather than 12 - a feature that has never been seen in humans before.

"We actually believe the girl was stillborn or died immediately after birth," said Prof Nolan.

"She was so badly malformed as to be unable to feed. In her condition, she would have ended up in the neonatal ICU."

However, access to advanced medical care was probably unavailable in the remote Chilean region where she was found. The skeleton's intact condition suggests it may be no more than 40 years old.

Future benefit

Prof Nolan began the scientific investigation of Ata in 2012, when a friend called saying he might have found an "alien".

He explained: "While this started as a story about aliens, and went international - it's really a story of a human tragedy. A woman had a malformed baby, it was preserved in a manner and then "hocked", or sold."

The scientists said that future studies of Ata had the potential to improve our understanding of the underlying basis of genetic skeletal disorders - with the potential to help others.

"Analysing a puzzling sample like the Ata genome can teach us how to handle current medical samples, which may be driven by multiple mutations," said Atul Butte, director of the Institute for Computational Health Sciences at the University of California, San Francisco.

"When we study the genomes of patients with unusual syndromes, there may be more than one gene or pathway involved genetically, which is not always considered."

Prof Nolan says further research into Ata's precocious bone aging could one day benefit patients. "Maybe there's a way to accelerate bone growth in people who need it, people who have bad breaks," he said. "Nothing like this had been seen before. Certainly, nobody had looked into the genetics of it."

He added: "I think it should be returned to the country of origin and buried according to the customs of the local people."

Follow Paul on Twitter. </s> Scientists have for the first time discovered a first-generation individual of mixed ancestry from two distinct human groups.

Analysis of a bone discovered in a Siberian cave revealed the female, who died 90,000 years ago, had a Neanderthal mother and a Denisovan father.

The 13-year-old female, nicknamed “Denny” by scientists, is an example of interbreeding between now-extinct human groups, say scientists.

Pontus Skoglund, population geneticist at the Francis Crick Institute, said: “To find a first-generation person of mixed ancestry from these groups is absolutely extraordinary.

“It’s really great science coupled with a little bit of luck.”

The complete picture of Denny’s ancestry had been incomplete for a number of years – only her mother’s side was known after researchers discovered mitochondiral DNA in her remains came from a Neanderthal.

The most recent study set out to compare DNA variation in Denny with that of three other hominins, a Neanderthal, a Denisovan and a modern-day human (Homo Sapien) from Africa.

Palaeogeneticists Viviane Slon and Svante Paabo at Germany’s Max Planck Institute for Evolutionary Anthropology carried out genome analysis on a bone taken from the Denisova cave in the Altai Mountains of Russia.

Bone fragment (“Denisova 11”) was found in 2012 at Denisova Cave in Russia by Russian archaeologists (T. Higham/University of Oxford)

A 40% match was found with the Denisovan, as well as a 40% match for the Neanderthal, while bone density gave away the teenager’s age.

Scientists confirmed Denny came from two separate hominins – and not two hybrids – by looking at where the genomes between Neanderthals and Denisovans differ.

After comparing Denny’s DNA to genomes of a Neanderthal and a Denisovan, researchers found she had one set of chromosomes from each hominin.

Denisovans, now extinct, were a group of humans first identified from DNA analysis of a finger bone discovered in the same place a decade ago.

Neanderthals also lived in the cave.

Scientists have been aware of breeding between diffrent humant human groups, including between Denisovans and Homo Sapiens, thanks to variation among humans.

But this is the first time a first-generation offspring from the pairing has been discovered.

Scientists now think such a mix could be more common than initially thought.

“We knew from previous studies that Neandertals and Denisovans must have occasionally had children together, but I never thought we would be so lucky as to find an actual offspring of the two groups,” said Slon.

The findings were published in Nature. </s> Image copyright Getty Images

Precise "chemical surgery" has been performed on human embryos to remove disease in a world first, Chinese researchers have told the BBC.

The team at Sun Yat-sen University used a technique called base editing to correct a single typo out of the three billion "letters" of our genetic code.

They altered lab-made embryos to remove the disease beta-thalassemia. The embryos were not implanted.

The team says the approach may one day treat a range of inherited diseases.

Base editing alters the fundamental building blocks of DNA: the four bases adenine, cytosine, guanine and thymine.

They are commonly known by their respective letters, A, C, G and T.

All the instructions for building and running the human body are encoded in combinations of those four bases.

Image copyright Getty Images

The potentially life-threatening blood disorder beta-thalassemia is caused by a change to a single base in the genetic code - known as a point mutation.

The team in China edited it back.

They scanned DNA for the error then converted a G to an A, correcting the fault.

Junjiu Huang, one of the researchers, told the BBC News website: "We are the first to demonstrate the feasibility of curing genetic disease in human embryos by base editor system."

He said their study opens new avenues for treating patients and preventing babies being born with beta-thalassemia, "and even other inherited diseases".

The experiments were performed in tissues taken from a patient with the blood disorder and in human embryos made through cloning.

Genetics revolution

Base editing is an advance on a form of gene-editing known as Crispr, that is already revolutionising science.

Crispr breaks DNA. When the body tries to repair the break, it deactivates a set of instructions called a gene. It is also an opportunity to insert new genetic information.

Base editing works on the DNA bases themselves to convert one into another.

Prof David Liu, who pioneered base editing at Harvard University, describes the approach as "chemical surgery".

He says the technique is more efficient and has fewer unwanted side-effects than Crispr.

He told the BBC: "About two-thirds of known human genetic variants associated with disease are point mutations.

"So base editing has the potential to directly correct, or reproduce for research purposes, many pathogenic [mutations]."

Image copyright Getty Images

The research group at Sun Yat-sen University in Guangzhou hit the headlines before when they were the first to use Crispr on human embryos.

Prof Robin Lovell-Badge, from the Francis Crick Institute in London, described parts of their latest study as "ingenious".

But he also questioned why they did not do more animal research before jumping to human embryos and said the rules on embryo research in other countries would have been "more exacting".

The study, published in Protein and Cell, is the latest example of the rapidly growing ability of scientists to manipulate human DNA.

It is provoking deep ethical and societal debate about what is and is not acceptable in efforts to prevent disease.

Prof Lovell-Badge said these approaches are unlikely to be used clinically anytime soon.

"There would need to be far more debate, covering the ethics, and how these approaches should be regulated.

"And in many countries, including China, there needs to be more robust mechanisms established for regulation, oversight, and long-term follow-up."

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