The Neanderthal specimens have some features that are more characteristic of modern human teeth
Prehistoric teeth unearthed at a site in Jersey reveal signs of interbreeding between Neanderthals and our own species, scientists say.
UK experts re-studied 13 teeth found between 1910 and 1911 at La Cotte de St Brelade in the island’s south-west.
They were long regarded as being typical Neanderthal specimens, but the reassessment also uncovered features characteristic of modern human teeth.
The teeth may represent some of the last known Neanderthal remains.
As such, they might even yield clues to what caused the disappearance of our close evolutionary cousins.
The Neanderthals evolved around 400,000 years ago and inhabited a large area from western Europe to Siberia.
They were typically shorter and stockier than modern humans, with a thick ridge of bone overhanging the eyes.
They finally disappeared around 40,000 years ago, just as anatomically modern humans (Homo sapiens), a newly arrived species from Africa, was settling in Europe.
However, the two types of human may have overlapped for at least 5,000 years.
The teeth were discovered on a small granite ledge at the cave site.
They were previously thought to belong to a single Neanderthal individual. However, the new research found they were from at least two adults.
The researchers used computed tomography (CT) scans of the teeth to study them at a level of detail that wasn’t available to researchers in the past.
‘Dual ancestry’
While all the specimens have some Neanderthal characteristics, some aspects of their shape are more typical of teeth from modern humans.
This suggests these were traits that were prevalent in their population.
Research leader Prof Chris Stringer, from London’s Natural History Museum, said: “Given that modern humans overlapped with Neanderthals in some parts of Europe after 45,000 years ago, the unusual features of these La Cotte individuals suggest that they could have had a dual Neanderthal-modern human ancestry.”
At the time these individuals were alive, the climate in this part of the world was colder than it is today and the sea level was tens of metres lower.
Co-author Dr Matt Pope, from the Institute of Archaeology at University College London (UCL), said the area would have been “fantastic for hunting”, because of its “dead-end valleys and blind gulleys”.
“Caves of that scale and size are extremely rare in that landscape,” he said, adding: “It seems to be embedded in their routines, coming back to that place for tens of thousands of years.”
The specimens were originally excavated more than 100 years ago
In fact, there is a record of occupation at the La Cotte site going back to 250,000 years ago.
The human teeth are thought to be around 48,000 years old, close to the presumed Neanderthal extinction date of 40,000 years ago.
So, rather than going extinct in the traditional sense, were Neanderthal groups simply absorbed into incoming modern human populations?
“This now needs to be a scenario that’s seriously considered, alongside others, and it’s going to emerge as we get more understanding of the process of genetic admixture,” Dr Pope told BBC News.
“But certainly, that word ‘extinct’ now starts to lose its meaning where you can see multiple episodes of admixture and the retention of a significant proportion of Neanderthal DNA in humans beyond sub-Saharan Africa.”
Neanderthals contributed 2-3% of the genomes – the genetic instruction booklet for making a person – of people with ancestry from outside Africa.
“This idea of a hybrid population could be tested by the recovery of ancient DNA from the teeth, something that is now under investigation,” said Prof Stringer.
The study has been published in the Journal of Human Evolution.
The Neanderthal specimens have some features that are more characteristic of modern human teeth
Prehistoric teeth unearthed at a site in Jersey reveal signs of interbreeding between Neanderthals and our own species, scientists say.
UK experts re-studied 13 teeth found between 1910 and 1911 at La Cotte de St Brelade in the island’s south-west.
They were long regarded as being typical Neanderthal specimens, but the reassessment also uncovered features characteristic of modern human teeth.
The teeth may represent some of the last known Neanderthal remains.
As such, they might even yield clues to what caused the disappearance of our close evolutionary cousins.
The Neanderthals evolved around 400,000 years ago and inhabited a large area from western Europe to Siberia.
They were typically shorter and stockier than modern humans, with a thick ridge of bone overhanging the eyes.
They finally disappeared around 40,000 years ago, just as anatomically modern humans (Homo sapiens), a newly arrived species from Africa, was settling in Europe.
However, the two types of human may have overlapped for at least 5,000 years.
The teeth were discovered on a small granite ledge at the cave site.
They were previously thought to belong to a single Neanderthal individual. However, the new research found they were from at least two adults.
The researchers used computed tomography (CT) scans of the teeth to study them at a level of detail that wasn’t available to researchers in the past.
‘Dual ancestry’
While all the specimens have some Neanderthal characteristics, some aspects of their shape are more typical of teeth from modern humans.
This suggests these were traits that were prevalent in their population.
Research leader Prof Chris Stringer, from London’s Natural History Museum, said: “Given that modern humans overlapped with Neanderthals in some parts of Europe after 45,000 years ago, the unusual features of these La Cotte individuals suggest that they could have had a dual Neanderthal-modern human ancestry.”
At the time these individuals were alive, the climate in this part of the world was colder than it is today and the sea level was tens of metres lower.
Co-author Dr Matt Pope, from the Institute of Archaeology at University College London (UCL), said the area would have been “fantastic for hunting”, because of its “dead-end valleys and blind gulleys”.
“Caves of that scale and size are extremely rare in that landscape,” he said, adding: “It seems to be embedded in their routines, coming back to that place for tens of thousands of years.”
The specimens were originally excavated more than 100 years ago
In fact, there is a record of occupation at the La Cotte site going back to 250,000 years ago.
The human teeth are thought to be around 48,000 years old, close to the presumed Neanderthal extinction date of 40,000 years ago.
So, rather than going extinct in the traditional sense, were Neanderthal groups simply absorbed into incoming modern human populations?
“This now needs to be a scenario that’s seriously considered, alongside others, and it’s going to emerge as we get more understanding of the process of genetic admixture,” Dr Pope told BBC News.
“But certainly, that word ‘extinct’ now starts to lose its meaning where you can see multiple episodes of admixture and the retention of a significant proportion of Neanderthal DNA in humans beyond sub-Saharan Africa.”
Neanderthals contributed 2-3% of the genomes – the genetic instruction booklet for making a person – of people with ancestry from outside Africa.
“This idea of a hybrid population could be tested by the recovery of ancient DNA from the teeth, something that is now under investigation,” said Prof Stringer.
The study has been published in the Journal of Human Evolution.
Where does the mind ‘meet’ the brain? While there’s no shortage of research into the effects of psychedelics, drugs like LSD still have much to teach us about the way the brain operates – and can shine a light on the mysterious interface between consciousness and neural physiology, research suggests.
In a new study investigating the effects of LSD on volunteers, scientists found that the psychedelic enables the brain to function in a way beyond what anatomy usually dictates, by altering states of dynamic integration and segregation in the human brain.
“The psychedelic compound LSD induces a profoundly altered state of consciousness,” explains first author and neuroscience researcher Andrea Luppi from the University of Cambridge.
“Combining pharmacological interventions with non-invasive brain imaging techniques such as functional MRI (fMRI) can provide insight into normal and abnormal brain function.”
The new research falls within the study of dynamic functional connectivity – the theory that brain phenomena demonstrate states of functional connectivity that change over time, much in the same way that our stream of consciousness is dynamic and always flowing.
As this happens, and the human brain processes information, it has to integrate that information into an amalgamated form of understanding – but at the same time segregate information as well, keeping distinct sensory streams separate from one another, so that they can be handled by particular neural systems.
This distinction – the dynamics of brain integration and segregation – is something that gets affected by psychedelic drugs, and with the advent of brain imaging technology, we can observe what happens when our regular functional connectivity gets disrupted.
In the study, a group of 20 healthy volunteers underwent brain scans in two separate sessions, a fortnight apart. In one of the sessions, the participants took a placebo before entering the fMRI scanner, while in the other slot, they were given an active dose of LSD.
In comparing the results from the two sessions, the researchers found that LSD untethers functional connectivity from the constraints of structural connectivity, while simultaneously altering the way that the brain handles the balancing act between integration and segregation of information.
“Our main finding is that the effects of LSD on brain function and subjective experience are not uniform in time,” Luppi says.
“In particular, the well-known feeling of ‘ego dissolution’ induced by LSD correlates with reorganisation of brain networks during a state of high global integration.”
In effect, the drug’s state of altered consciousness could be seen as an abnormal increase in the functional complexity of the brain – with the data showing moments where the brain revealed predominantly segregated patterns of functional connectivity.
In other words, the ‘ego dissolution’ of a psychedelic trip might be the subjective experience of your brain cranking up its segregation dynamics, decoupling the brain’s structure from its functioning – meaning your capacity to integrate and amalgamate separate streams of information into a unified whole becomes diminished.
“Thus, LSD appears to induce especially complex patterns of functional connectivity (FC) by inducing additional decoupling of FC from the underlying structural connectome, precisely during those times when structural-functional coupling is already at its lowest,” the authors explain in their paper.
“Due to the effects of LSD, the brain is free to explore a variety of functional connectivity patterns that go beyond those dictated by anatomy – presumably resulting in the unusual beliefs and experiences reported during the psychedelic state.”
Apple’s iPad Pro (2020) is arguably the most powerful and popular tablet on the market. But it doesn’t come cheap, which is why we’re always super-excited when great deals on the device pop-up. Right now, Amazon has the 2020 12.9-inch iPad Pro for £912, that’s a very decent £57 saving.
Over the in the US, there’s a similar deal on Amazon, with the retailer knocking $59 off the price of the same model iPad Pro, now down to $940.
This 2020 iPad Pro boasts a 12Z Bionic chip, which rivals that of many laptops available today. It also houses an eight-core graphics processor that can handle everything from gaming to 4K video editing, with ease.
While these might not seem like massive savings, finding any kind of Apple discount is rare, especially on the latest models in the iPad line-up. So if you’ve been thinking of investing in Apple’s Pro tablet, then see below for the cheapest prices you’ll currently find on the web.
Best Apple iPad Pro deals: US
Lowest price
Apple iPad Pro (2020): $999 $939.92 at Amazon Save $59: Amazon has knocked almost $60 off this fourth generation, 12.9-inch iPad Pro with Wi-Fi and 128GB SSD. Perfect if you don’t need huge amounts of storage space, and all for well under a grand. View Deal
Apple iPad Pro (2020): $1,299 $1,223.93 at Amazon Save $75: If you’re after a 12.9-inch iPad Pro with a bit more room, this 512GB SSD model might be a better choice. It’s slightly more expensive, but has $75 knocked off, which is the cheapest you’ll find this model on the web right now. View Deal
Best iPad Pro deals: UK
Best deal
Apple iPad Pro (2020): $969 $912 at Currys Save £57: Get a very decent £57 off off this 12.9-inch iPad Pro with 128GB of storage, a powerful A12Z Bionic chip, Face ID, Wi-FI, 12 megapixel camera with 4K HD video, and up to 10 hours of battery life. View Deal
Apple iPad Pro (2020): £969 £912 at Amazon Save £57: If you miss out on the deal at Currys, Amazon has the exact same offer, with £57 off the same model iPad Pro. Now just over £900, this is an incredible price for this super-powerful tablet, armed with Wi-Fi and 128GB SSD. View Deal
Apple iPad Pro (2018): £769 £726.70 at Amazon Save £42: It might not be the shiny new version, but this 2018 iPad Pro model still packs a punch. Complete with 11-inch screen, Wi-Fi and 128GB SSD, this quality device can handle even the most complex of tasks – and it’s a steal at just over £700.
View Deal
If none of these iPad deals are quite right for you, see below for more of today’s best deals.
Can you picture Jupiter without any observable clouds or haze? It isn’t easy since Jupiter’s latitudinal cloud bands and its Great Red Spot are iconic visual features in our Solar System. Those features are caused by upswelling and descending gas, mostly ammonia. After Saturn’s rings, Jupiter’s cloud forms are probably the most recognizable feature in the Solar System.
Now astronomers with the Center for Astrophysics | Harvard & Smithsonian (CfA) have found a planet similar in mass to Jupiter, but with a cloud-free atmosphere.
These planets are scarce, and astronomers think only about 7% of exoplanets are like this. The discovery allows scientists to study how they form. Without clouds in the way, a clearer view awaits.
The team of astronomers behind the finding published their results in The Astrophysical Journal Letters. The title is “Evidence of a Clear Atmosphere for WASP-62b: The Only Known Transiting Gas Giant in the JWST Continuous Viewing Zone.” Lead author of the study is Munazza Alam, a grad student at the CfA.
WASP-62b is the nearest planet to WASP-62, a main-sequence star almost 600 light-years from Earth. 62b is the only planet in the system. It’s just over half as massive as Jupiter, and orbits WASP-62 in about 4.5 days. It’s about 1.4 times as large as Jupiter. It falls squarely into the category of Hot Jupiters, with an average temperature of about 1330 K (1057 C; 1934 F.)
Can you picture Jupiter without clouds? We can’t either. Image Credit: Hubble/NASA/ESA
The planet’s temperature, size, and density properties aren’t rare. What’s rare is the cloudlessness of its atmosphere. And the exoplanet’s atmosphere is of special interest to lead author Alam. In a press release, Alam said, “For my thesis, I have been working on exoplanet characterization. I take discovered planets, and I follow up on them to characterize their atmospheres.”
The WASP name comes from the Wide Angle Search for Planets (WASP) South. The planet was first discovered in 2012 and was one of seven Hot Jupiters found at the same time.
WASP-62b was discovered with WASP, but Alam and her colleagues used the Hubble to study it more closely. “I’ll admit that at first, I wasn’t too excited about this planet,” Alam said. “But once I started to take a look at the data, I got excited.”
Using spectroscopy, they watched closely as the planet transited in front of its star three times, looking for potassium and sodium. As the starlight passed through the planet’s atmosphere they identified sodium’s complete spectroscopic signature, but no potassium. The sodium signature told them that the atmosphere was clear.
“This is smoking gun evidence that we are seeing a clear atmosphere,” Alam said.
A screenshot of WASP-62b from NASA’s Eyes on Exoplanets website. Image Credit: NASA
In an email exchange with Universe Today, Alam elaborated on the team’s spectroscopic findings and what they mean.
The focus on potassium and sodium is based on a couple of things. First of all, their spectra are easily observable in optical light. “Sodium and potassium are two species that are readily observable in exoplanet atmosphere observations taken at optical wavelengths, and their presence or absence can help us infer if there are clouds or hazes in an exoplanet’s atmosphere,” Alam said.
Sodium and potassium also play a role in exoplanet atmospheres, though the details aren’t clear. “Sodium and potassium are two elements that play an interesting – yet not well understood – role in the atmospheric physics and chemistry of exoplanets,” Alam explained. She also mentioned that sodium was the first absorption feature identified in an exoplanet’s atmosphere.
The detection of sodium’s complete spectroscopic signature tells astronomers that the atmosphere is clear, even if there’s no way to see the atmosphere. “Clouds in a planet’s atmosphere will mask or obscure parts of the absorption line,” Alam explained. “In the absence of clouds, we can resolve the full sodium signature – which has a tent-like shape with a peak at the core of the absorption feature and broad line wings. For our observations of WASP-62b, this is the second time that we’ve observed the full sodium feature (i.e., with its line wings) in an exoplanet and the first time that we’ve done so from space.”
This figure from the study shows the Hubble Space Telescope Imaging Spectrograph data for WASP-62b and the only other known exoplanet with a clear atmosphere, WASP-96b. Both exoplanets show the “…prominent pressure-broadened wings of the Na D-lines at 0.59 ?m.” Seeing the sodium spectrum with wings indicates that both planets have clear atmospheres. WASP-96b also shows the presence of lithium and potassium. Image Credit: Alam et al, 2021.
But the complete sodium signature does more than tell us that the exoplanet’s atmosphere is cloud-free. It can help explain how much sodium there is and indicate what other elements are in the atmosphere.
“Not only does it tell us that the atmosphere is clear, it can also help us to constrain really precise abundances (quantities) of sodium – as well as other elements that are present in the planet’s atmosphere,” Alam said. “These abundances are useful for measuring key quantities that can help us trace back the origins and evolution of this planet.”
There’s clearly something different going on when a cloud-free planet forms. Since there are so few of them, astronomers are only at the beginning of studying them. The only other cloud-free exoplanet that we know of is the hot Saturn named WASP-96b, found in 2018.
It’ll be up to the James Webb Space Telescope to examine this exoplanet’s atmosphere more closely. And its clear skies make that prospect even more exciting. The Webb’s advanced observing capabilities mean it should be able to identify even more of the chemical constituents in WASP-62b’s atmosphere.
“In preparation for JWST, identifying targets that are cloud-free/haze-free is important for mobilizing community efforts to observe the best planets for detailed atmospheric follow-up.”
From “Evidence of a Clear Atmosphere for WASP-62b: The Only Known Transiting Gas Giant in the JWST Continuous Viewing Zone.”
Due to JWST’s orientation and position in space, it’ll have two small continuous viewing zones (CVZ). They’re centred on each pole of the ecliptic. Fortune is smiling on Alam and other exoplanet scientists because WASP-62b is in one of Webb’s CVZs.
James Webb’s field of view contains two continuous viewing zones, indicated by ovals in the image. The rest of the JWST’s field of regard sweeps through the sky over time. As luck would have it, WASP-62b is in one of JWST’s CVZs. Image Credit: NASA/JWST.
The team of researchers even predicted what the JWST might find in 62b’s atmosphere. In their paper they write “We predict that JWST observations of WASP-62b, within the scope of the ERS program, can conclusively detect Na (12.1?), H2O (35.6?), FeH (22.5?), SiH (6.3?), NH3 (11.1?), CO (8.1?), CO2 (9.7?), and CH4 (3.6?).” They also say that the JWST can offer precise constraints on the abundance of chemicals in the atmosphere.
As part of their work, and to help make the case for follow-up observations with the Webb, the team predicted what the Webb might find. Image Credit: Alam et al, 2021.
In their conclusion, the authors make their case for follow-up observations of WASP-62b with the JWST.
“In preparation for JWST, identifying targets that are cloud-free/haze-free is important for mobilizing community efforts to observe the best planets for detailed atmospheric follow-up. Although alternative targets have since been put forward, WASP-62 is the only star in the JWST CVZ with a known transiting giant planet that is bright enough for high-quality atmospheric characterization via transit spectroscopy.”
The James Webb Space Telescope is scheduled to launch at the end of October 2021.
Paleontologists from National Taiwan University believe the 6.5-foot-long burrow was once home to a worm-like predator that would surface from the seabed to ambush sea creatures and drag them, alive, into its lair.
Experts working in northeastern Taiwan reconstructed large, L-shaped burrows dating back to up to 23 million years ago from layers of seafloor using trace fossils — geological features, like track marks, burrows and plant root cavities found preserved in rocks, which experts use to draw conclusions on the behavior of ancient creatures.
Using 319 specimens, experts reconstructed a trace fossil of adugout — dubbed Pennichnus formosae— which was 6.5-feet long and around an inch in diameter, and say morphological evidence indicates that the tunnels were home to giant marine worms, like the modern-day bobbit worm.
The bobbit worm, or sand striker (Eunice aphroditois), is an aquatic predatory bristle worm that ranges from 4 inches to 10 feet in length and lives in burrows it creates in the ocean floor. The bobbit worm takes its name from the Lorena and John Wayne Bobbitt case, in which Lorena cut off her husband John Wayne’s penis with a kitchen knife.
Living mainly in the Pacific Ocean, bobbit worms hide in long, narrow burrows in the seafloor and propel upward to grab unsuspecting fish, large molluscs and other worms, before dragging them, still alive, back to their dens.
In the study, published in the journal Scientific Reports, the report authors note that the retreat of an ancient worm and prey into the sediment could have caused the “feather-like” structures preserved in Pennichnus formosae.
They identified a high concentration of iron at the top section of the burrow, and believe the worm could have secreted mucus to reinforce the burrow wall.
“We hypothesize that about 20 million years ago, at the southeastern border of the Eurasian continent, ancient Bobbit worms colonized the seafloor waiting in ambush for a passing meal,” the report authors wrote.
“When prey came close to a worm, it exploded out from its burrow, grabbing and dragging the prey down into the sediment. Beneath the seafloor, the desperate prey floundered to escape, leading to further disturbance of the sediment around the burrow opening,” they described.
