Tag: Humans

According To A Chinese Scientist, World’s First Gene-Edited Babies Have Arrived

An embryo being given CRISPR machinery

A Chinese scientist has reported he’s created the world’s first gene-edited babies, an announcement that’s shocked the scientific community because it defies an unofficial international moratorium on editing human embryos intended for a pregnancy.

He Jiankui, a professor at the Southern University of Science and Technology in Shenzhen, is claiming to have used the revolutionary gene editing technology CRISPR to tweak the DNA of human embryos during in-vitro fertilization, resulting in the birth of twin girls several weeks ago.

The objective, He said, was to remove a gene called CCR5 so the girls might be resistant to potential infection with HIV/AIDS.

If the experiment’s results are confirmed by independent scientists, He would be the first scientist known to use CRISPR to edit human embryos resulting in a live birth.

He’s experiment, first reported by the MIT Technology Review and the AP on Sunday, has not been published in a scientific journal and the data have not been peer-reviewed.

He shared his findings with the media on Monday just before the Second International Summit on Human Genome Editing in Hong Kong, and would not reveal the names of the parents or babies involved.

Researchers were calling for a “take it slow” approach on CRISPR in humans

The last several years in science have unleashed the CRISPR revolution. CRISPR-Cas9 — or CRISPR, as it’s known — is a tool that allows researchers to control which genes get expressed in plants, animals, and even humans; to delete undesirable traits and, potentially, add desirable traits; and to do all this more quickly, and with more precision, than ever before.

Even more fantastically, it’s at least theoretically possible to use CRISPR to hack the human species — to modify the genome to create resistance to or completely eliminate — chronic or infectious diseases.

He Jiankui says two babies have been born as a result of his CRISPR experiment

But just because we may have the power to do something doesn’t mean we should.

And talking about what scientists should do with CRISPR was the point of the international summit at the National Academy of Sciences in 2015.

There, scientists from around the world met to discuss how society should proceed with this technology.

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Pass it on: New Scientist

The Most Inbred People Of All Time | Random Thursday

From the most powerful royalty in history to an uncontacted village in New York State, we’re talking about some of the most inbred people of all time.

The Blue Fugates of Kentucky were an isolated group of settlers who, through a rare recessive gene, developed blue skin. Due to their blue skin and their isolated location, they began to inbreed, eventually becoming something of a local legend – the blue hillbillies that live in the woods – until they reappeared in the 1960s.

Allentown, New York, is a village in New York State that was cut off from the rest of society after a dam flooded the valley where they lived. They call their community The Hollow, but outsiders call it Allentown because almost everybody there is from the same family.

The Habsburgs of Europe were one of the most powerful families in history, ruling over the Holy Roman Empire in Eastern Europe until the early 20th century. But one segment of the Habsburgs in Spain, known as the Spanish Habsburgs, participated in incest and inbreeding for so long that they developed The Habsburg Jaw – a genetic deformity that got so bad that many could barely speak. It was Charles II of Spain that finally put an end to this practice because he was so inbred that he couldn’t reproduce.

And the Egyptian royal family of ancient Egypt practiced inbreeding for over a thousand years because they believed that the only person who could mate with a pharaoh was someone else from their family – they were living gods after all. By the time King Tutankhamen was born, their lineage was so ruined that he had multiple genetic deformities and died at only 18.

10 Famous Human Oddities

There was a time when traveling circuses and freak shows were the preeminent form of entertainment of the day. Some people made a great living as human oddities, showing off their natural (and unnatural) bodies. Here are 10 of the most famous.

Scientists Discover A New Type Of Brain Cell In Humans

An international team of 34 scientists has identified a new type of brain cell in humans not found in other well-studied species.

The discovery of “Rosehip” neurons, published today in the journal Nature Neuroscience, raises a number of questions: How does it influence human behavior and experience?

How does it differentiate us from other species? Can it be found in primates and other cognitively advanced species?

But there is one issue this discovery highlights immediately: there’s a neuron in human brains that is missing from the brains of mice and other animals used to model human brains in experiments.

Does this mean current animal models yield distorted results? “If we want to understand how the human brain works, we need to study humans or closely related species,” says Trygve Bakken, co-author of the paper and a neuroscientist at the Allen Institute for Brain Science.

The flow of info

Rosehip neurons are inhibitory neurons that form synapses with pyramidal neurons, the primary excitatory neurons in the prefrontal cortex.

We all have inhibitory neurons and excitatory neurons,” says Bakken, “but this particular type of inhibitory neuron is what’s new in this study. It’s special based on its shape and its connections and also the genes that it expresses.

When a traffic signal turns red it helps controls the flow of traffic. Similarly, inhibitory neurons help control the flow of electrochemical information.

The type of information rosehip neurons control, and why they appear particular to humans, is yet to be discovered. “It has these really discrete connections with [pyramidal] neurons,” says Bakken.

It has the potential to sort of manipulate the circuit in a really targeted way, but how that influences behavior will have to come in later work.”

Found in the neocortex of human brains

The researchers identified rosehip neurons by looking at brain samples from two males who died in their 50’s and donated their bodies to science.

The brain slabs were tissue from the neocortex, a most recent evolutionary development inside our skulls responsible for higher-order thinking.

The neocortex, the outermost layer of cells, is greatly expanded in humans–about a thousandfold compared to mice,” says Bakken.

From neurological studies, if you have a stroke in your neocortex for example, it really impacts your ability to do these sorts of high-order cognitive processing.

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Pass it on: Popular Science

Did Humans And Neanderthals Interbreed?

In 1856, laborers working in a limestone quarry near Düsseldorf, Germany, unearthed bones that scientists initially thought belonged to a deformed human.

The skull was oval shaped, with a low, receding forehead, distinct brow ridges, and bones that were unusually thick.

Subsequent study revealed that the remains belonged to a previously unknown species of hominid, or early human ancestor, that was similar to our own species, Homo sapiens.

In 1864, the specimen was dubbed Homo neanderthalensis, after the Neander Valley where the skull was discovered.

Neanderthals were our closest evolutionary relatives. Their ancestors left Africa before modern humans, venturing into Europe as far back as 500,000 years ago, and were still there when our ancestors embarked on the same journey about 70,000 years ago.

Neanderthals and modern humans actually lived alongside each other in Europe for several thousand years before Neanderthals vanished some 30,000 years ago.

Their disappearance is one of the most enduring mysteries in all of human evolution.

But perhaps the most controversial theory for why there are no more Neanderthals is that they interbred with modern humans and the two lineages merged into one.

According to this idea, most of modern humanity—with the possible exception of some Africans who are descended from humans who never left Africa—is part Neanderthal.

Evidence for interbreeding comes largely from the study of fossils that, according to some scientists, show hybrid traits from both species.

For example, anthropologist Erik Trinkhaus believes that a 29,000-year-old skull discovered in Romania belonging to a modern human has an unusually long and flat forehead and unusually large molars.

There is some genetic evidence to support the interbreeding theory as well. In 2010, a team of scientists comparing a rough draft of the Neanderthal genome with that of modern humans concluded that most humans have 1 to 3 percent Neanderthal DNA.

The team suggested that the first opportunity for Neanderthal-human interbreeding probably occurred about 60,000 years ago, after modern humans had left Africa but before they had made significant inroads into Europe.

However, recent computer models suggest the genetic similarities shared between Neanderthals and modern humans could also be due to the two species sharing a recent common ancestor rather than hybridization.

Neanderthals: We Were Not Alone

Neanderthal spear.

The three human subspecies known to have hybridised to produce the present human population of the planet, Neanderthals, Homo sapiens and Denisovans, last had a common ancestor more than half a million years ago.

Until now it has been assumed that the only branch of her descendants to think symbolically was us, Homo sapiens.

In fact, until the development of sequencing techniques sensitive enough to work on ancient DNA, it was thought that the other two species had died out entirely, rather than leaving portions of their genome in European and Melanesian populations respectively.

But the discovery, reported last week, of palaeolithic art at four sites in Spain that dates from the time when the peninsula was occupied only by Neanderthals, shows that they worked with symbols of stone and paint.

We have no idea what these markings mean. That is in the nature of symbolism, and indeed of language: the meaning of a sound, or a marking on the wall, is given by the community that uses it; it can’t be read by outsiders.

We already know that Neanderthals were anatomically equipped for speech; their use of painted symbols suggests that they could make audible symbols and not just visible ones.

One of the effects of the discovery reported last week has been to push one of the standard tropes of science fiction 40,000 years into our past.

That was when Homo sapiens met Homo neanderthalensis, another symbolically intelligent species, and our ancestors realised that they were not alone in the universe.

We can deduce that these encounters must have been reasonably peaceable, because Europeans and all other populations outside Africa carry some Neanderthal DNA.

Animal studies have shown that almost all of the capacities that we once considered uniquely human are shared with animals.

Some birds are capable of choosing and using wooden tools, chimpanzees use stone ones, and even sheep recognise one another as individuals.

Many creatures communicate with sounds, as well as with smells and expressions. But only humans have symbolic language, so far as we know.

Only humans form concepts and combine them as if they were physical tools before using them to shape the world. Now it seems that to be human in this sense is an older and stranger thing than anyone had earlier dared to dream.

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Pass it on: Popular Science

Oldest Fossils Of Homo Sapiens Found in Morocco


Fossils discovered in Morocco are the oldest known remains of Homo sapiens, scientists reported, a finding that rewrites the story of mankind’s origins and suggests that our species evolved in multiple locations across the African continent.

Until now, the oldest known fossils of our species dated back just 195,000 years. The Moroccan fossils, by contrast, are roughly 300,000 years old.

Remarkably, they indicate that early Homo sapiens had faces much like our own, although their brains differed in fundamental ways.

Today, the closest living relatives to Homo sapiens are chimpanzees and bonobos, with whom we share a common ancestor that lived over six million years ago.

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Pass it on: Popular Science