- UFC 282 REACTIONS!!! | Round-Up w/ Paul Felder & Michael Chiesa UFC – Ultimate Fighting Championship
- ‘Uncrowned champion’ Magomed Ankalaev done with Vegas (not UFC): ‘The judges were horrible’ MMA Mania
- ‘It was mistranslated’ – Magomed Ankalaev clarifies post-fight interview after drawing Jan Blachowicz at UFC … Bloody Elbow
- Magomed Ankalaev issues statement on his split draw against Jan Blachowicz at UFC 282: “It’s hard to describe the words” BJPENN.COM
- Jan Blachowicz defends UFC 282 stalemate, criticizes Magomed Ankalaev’s post-fight comments: ‘One dude cried’ MMA Fighting
- View Full Coverage on Google News
Tag Archives: the
Unexpected Solar Wind Stream Hits Earth at 372 Miles Per Second
On Sunday, Earth’s magnetic field was pelted by a solar wind stream reaching velocities of more than 600 kilometers (372 miles) per second.
While that’s nothing too alarming – solar storms often pummel our planet triggering spectacular auroras – what is weird is that this storm was totally unexpected.
“This event was not in the forecast, so the resulting auroras came as a surprise,” SpaceWeather reported.
Solar wind occurs when a stream of highly energized particles and plasma can no longer be held back by the Sun’s gravity and burst out towards Earth.
There’s a lot we still don’t know about how our Sun works, but these emissions are thought to come from large bright patches on the Sun known as ‘coronal holes’ and scientists do a great job of monitoring them from here on Earth.
Through this monitoring, they’re able to create space weather ‘forecasts’ that not only predict when solar storms or solar flares, also known as coronal mass ejections (CMEs), are heading our way, but how powerful they’ll be.
But that doesn’t mean we can’t still get surprised like we did over the weekend.
Early on Sunday, NASA’s Deep Space Climate Observatory (DSCOVR) noticed light solar wind streams, which increased significantly and unexpectedly throughout the day.
The cause of this solar storm is still unknown, but SpaceWeather speculates it could have been the early arrival of solar wind expected to come from an equatorial hole in the Sun’s atmosphere two days later.
Or it could have been a missed coronal mass ejection (CME).
“A discontinuity in solar wind data at 0045 UT on Aug. 7th hints at a shock wave embedded in the solar wind,” writes Space Weather.
“These days, the active sun is producing so many minor explosions, it is easy to overlook faint CMEs heading for Earth.”
At the time of writing, the high-velocity solar wind continues to slam into Earth’s magnetic field, with records showing the speed is reaching 551.3 kilometers (343 miles) per second as of August 9, 0406 UTC (0006 ET).
The good news is that solar wind isn’t damaging to us here on Earth, safely protected by our planet’s atmosphere.
When it’s strong, though, it can impact our technologies, causing issues with telecommunication satellites and, in extreme cases, power grids.
These winds were classified as a moderate G2 solar storm – storms are ranked G1 at the lowest end of the scale all the way up to G5, which is a powerful solar storm.
G2 storms can affect high latitude power systems and could impact the orbit predictions of spacecraft, according to Space Weather.
If you feel like this all sounds familiar, that’s because we’ve witnessed a lot of solar storms this year, with the Sun now in the active phase of its 11-year solar cycle.
Already this year we’ve been hit by X-class flares and giant coronal holes, more than 2.5 times Earth’s size. Most of the time you’d have no idea this was happening.
Unless you’re an avid aurora watcher, that is.
Fortunately, followers of the Space Weather Alert Service were notified about the unforecast storm and were able to make it out to see the resulting powerful auroras and Steve, which were seen as far south as Pennsylvania.
“I was already in bed getting ready for sleep when the storm began,” astrophotographer Ruslan Merzlyakov told Space Weather.
“Rushing to the beach in Nykøbing Mors, I was able to photograph the first summer auroras in Denmark in 5 years.”
Who knows what the rest of the week may have in store for us.
The Universe Could ‘Bounce’ For Eternity. But It Still Had to Start Somewhere
From the smallest bacterium to the greatest galaxy, death looms on the horizon; even if, in cosmic terms, the time scales are too large for us to truly comprehend. Eventually, even the Universe itself should come to an end – when the last light winks out, and the cold, dense lumps of dead stars are all that remain.
That is, at least, how it is under current cosmological models. What if our Universe doesn’t die a cold death, but collapses, reinflates, and collapses again, over and over, like a giant cosmic lung?
It’s not exactly a widely accepted theory, but for some cosmologists, our Universe could be just one in a long series of births, deaths and rebirths that is without beginning or end – not a Big Bang, but a Big Bounce.
Now physicists have shown that the latest iteration of the Big Bounce hypothesis – which had solved significant problems with previous iterations – still has pretty major limitations.
“People proposed bouncing universes to make the Universe infinite into the past, but what we show is that one of the newest types of these models doesn’t work,” said physicist Will Kinney of the University at Buffalo.
“In this new type of model, which addresses problems with entropy, even if the Universe has cycles, it still has to have a beginning.”
Currently, the most accepted model of our Universe sees it emerge from a point of origin called a singularity. Around 13.8 billion years ago the Universe as we know it began to expand out of an impossibly dense bit of time and space … for some reason.
Unfortunately the models supporting a ‘Big Bang’ explanation have little to say much about what such a singularity might look like.
The Big Bounce hypothesis, as an alternative, could sidestep the issue of a singularity by doing away with it entirely. A collapsing universe would instead rebound before it ever reached such a model-breaking moment.
The hypothesis hasn’t been without its own issues, however. An endlessly “bouncing” Universe should also have endlessly growing entropy, the measure of disorder in the Universe. If the Big Bang was just one of an eternal series of bangs, the entropy should therefore have been really high; yet it wasn’t. In fact, if the Universe was high in entropy at the Big Bang, it couldn’t exist as we know it.
In 2019, the Big Bounce got a reprieve, with the publication of a revised model that contained a solution to this significant hurdle that had stymied the hypothesis for decades. Researchers found that the expansion of the Universe with each cycle dilutes entropy sufficiently to return the Universe to its original state before the next bounce.
This was a huge deal, seemingly putting the Big Bounce back on the table as a plausible cosmological model; but now, other scientists have done what scientists do best. They have poked a new hole in the revised model.
Kinney and his colleague, physicist Nina Stein, also of the University at Buffalo, conducted a series of calculations, and found that a cyclic Universe can’t stretch endlessly back into the past.
“Long story short, we showed that in solving the entropy problem, you create a situation where the Universe had to have a beginning,” Kinney explained. “Our proof shows in general that any cyclic model which removes entropy by expansion must have a beginning.”
That doesn’t mean that the cyclic Universe is dead in the water. The team notes that their work does not apply to physicist Roger Penrose’s model of the cyclic Universe, called conformal cyclic cosmology. According to his version of a repeating universe, each cycle expands infinitely with no period of contraction. That is pretty complex stuff, and is going to require further poking.
For now, however, it seems that the Big Bounce is, at the very least, going to require a bit more thought to remain viable.
“The idea that there was a point in time before which there was nothing, no time, bothers us, and we want to know what there was before that – scientists included,” Stein said. “But as far as we can tell, there must have been a ‘beginning’. There is a point for which there is no answer to the question, ‘What came before that?'”
The research has been published in the Journal of Cosmology and Astroparticle Physics.
Earth’s Days Are Mysteriously Getting Longer, Scientists Say
Atomic clocks, combined with precise astronomical measurements, have revealed that the length of a day is suddenly getting longer, and scientists don’t know why.
This has critical impacts not just on our timekeeping, but also things like GPS and other technologies that govern our modern life.
Over the past few decades, Earth’s rotation around its axis – which determines how long a day is – has been speeding up. This trend has been making our days shorter; in fact, in June 2022 we set a record for the shortest day over the past half a century or so.
But despite this record, since 2020 that steady speedup has curiously switched to a slowdown – days are getting longer again, and the reason is so far a mystery.
While the clocks in our phones indicate there are exactly 24 hours in a day, the actual time it takes for Earth to complete a single rotation varies ever so slightly. These changes occur over periods of millions of years to almost instantly – even earthquakes and storm events can play a role.
It turns out a day is very rarely exactly the magic number of 86,400 seconds.
The ever-changing planet
Over millions of years, Earth’s rotation has been slowing down due to friction effects associated with the tides driven by the Moon. That process adds about about 2.3 milliseconds to the length of each day every century. A few billion years ago an Earth day was only about 19 hours.
For the past 20,000 years, another process has been working in the opposite direction, speeding up Earth’s rotation. When the last ice age ended, melting polar ice sheets reduced surface pressure, and Earth’s mantle started steadily moving toward the poles.
Just as a ballet dancer spins faster as they bring their arms toward their body – the axis around which they spin – so our planet’s spin rate increases when this mass of mantle moves closer to Earth’s axis. And this process shortens each day by about 0.6 milliseconds each century.
Over decades and longer, the connection between Earth’s interior and surface comes into play too. Major earthquakes can change the length of day, although normally by small amounts.
For example, the Great Tōhoku Earthquake of 2011 in Japan, with a magnitude of 8.9, is believed to have sped up Earth’s rotation by a relatively tiny 1.8 microseconds.
Apart from these large-scale changes, over shorter periods weather and climate also have important impacts on Earth’s rotation, causing variations in both directions.
The fortnightly and monthly tidal cycles move mass around the planet, causing changes in the length of day by up to a millisecond in either direction. We can see tidal variations in length-of-day records over periods as long as 18.6 years.
The movement of our atmosphere has a particularly strong effect, and ocean currents also play a role. Seasonal snow cover and rainfall, or groundwater extraction, alter things further.
Why is Earth suddenly slowing down?
Since the 1960s, when operators of radio telescopes around the planet started to devise techniques to simultaneously observe cosmic objects like quasars, we have had very precise estimates of Earth’s rate of rotation.
A comparison between these estimates and an atomic clock has revealed a seemingly ever-shortening length of day over the past few years.
But there’s a surprising reveal once we take away the rotation speed fluctuations we know happen due to the tides and seasonal effects. Despite Earth reaching its shortest day on 29 June 2022, the long-term trajectory seems to have shifted from shortening to lengthening since 2020. This change is unprecedented over the past 50 years.
The reason for this change is not clear. It could be due to changes in weather systems, with back-to-back La Niña events, although these have occurred before. It could be increased melting of the ice sheets, although those have not deviated hugely from their steady rate of melt in recent years.
Could it be related to the huge volcano explosion in Tonga injecting huge amounts of water into the atmosphere? Probably not, given that occurred in January 2022.
Scientists have speculated this recent, mysterious change in the planet’s rotational speed is related to a phenomenon called the “Chandler wobble” – a small deviation in Earth’s rotation axis with a period of about 430 days.
Observations from radio telescopes also show that the wobble has diminished in recent years; the two may be linked.
One final possibility, which we think is plausible, is that nothing specific has changed inside or around Earth. It could just be long-term tidal effects working in parallel with other periodic processes to produce a temporary change in Earth’s rotation rate.
Do we need a ‘negative leap second’?
Precisely understanding Earth’s rotation rate is crucial for a host of applications – navigation systems such as GPS wouldn’t work without it. Also, every few years timekeepers insert leap seconds into our official timescales to make sure they don’t drift out of sync with our planet.
If Earth were to shift to even longer days, we may need to incorporate a “negative leap second” – this would be unprecedented, and may break the internet.
The need for negative leap seconds is regarded as unlikely right now. For now, we can welcome the news that – at least for a while – we all have a few extra milliseconds each day.
Matt King, Director of the ARC Australian Centre for Excellence in Antarctic Science, University of Tasmania and Christopher Watson, Senior Lecturer, School of Geography, Planning, and Spatial Sciences, University of Tasmania.
This article is republished from The Conversation under a Creative Commons license. Read the original article.
Earth Just Had Its Shortest Day on Record, Thanks to a ‘Wobble’
The Earth had its shortest ever day this summer, thanks to a wobble in its axis which meant it completed a single spin in a fraction of a second less than 24 hours.
June 29 was 1.59 milliseconds shorter than 86,400 seconds, or exactly 24 hours, according to the website timeanddate.com.
In recent decades the Earth has been more likely to slow down, giving marginally longer days. But in the last few years, that tendency reversed, and the days have been getting shorter and shorter.
If the Earth continues to speed up, this could lead to the first-ever requirement to subtract a second from atomic clocks.
The Earth is not perfect
It’s not uncommon for the Earth to wobble – the spinning which we experience as night and day does not always happen exactly in line with its axis, the line between the North and South Poles.
That’s because it is not a precise sphere.
The planet has a bulge at the equator, while the poles are slightly squashed, meaning Earth is slightly elliptical.
Other factors can mess with the spinning too, including ocean tides and gravity from the Moon.
The “Chandler wobble”
Leonid Zotov, a professor of mathematics, believes that the Earth may be spinning faster because of a periodic movement called the “Chandler wobble”.
The wobble was first spotted in the late 1880s, when astronomer Seth Carlo Chandler noticed the poles wobbled over a period of 14 months.
This wobble started to slow down in early 2000s, reaching historic minimums since 2017, per The Telegraph.
And between 2017 to 2020, “it disappeared”, Zotov told timeanddate.com.
Zotov is due to present this hypothesis at the Asia Oceania Geosciences Society, per timeanddate.com. It has not yet been peer-reviewed.
Earth wobbles don’t change much in day-to-day life. But they are important to keep track of, so the atomic clock can remain accurate to precisely coordinate GPS and Earth-observing satellites.
This article was originally published by Business Insider.
More from Business Insider:
New Study Offers a Surprising Timeline For Earth’s Sixth Mass Extinction
A climate scientist at Tohoku University in Japan has run the numbers and does not think today’s mass extinction event will equal that of the previous five. At least not for many more centuries to come.
On more than one occasion over the past 540 million years, Earth has lost most of its species in a relatively short geologic time span.
These are known as mass extinction events, and they often follow closely on the heels of climate change, whether it be from extreme warming or extreme cooling, triggered by asteroids or volcanic activity.
When Kunio Kaiho tried to quantify the stability of Earth’s average surface temperature and the planet’s biodiversity, he found a largely linear effect. The greater the temperature change, the greater the extent of extinction.
For global cooling events, the greatest mass extinctions occurred when temperatures fell by about 7°C. But for global warming events, Kaiho found the greatest mass extinctions occurred at roughly 9°C warming.
That’s much higher than previous estimates, which suggest a temperature of 5.2°C would result in a major marine mass extinction, on par with the previous ‘big five’.
To put that in perspective, by the end of the century, modern global warming is on track to increase surface temperatures by as much as 4.4°C.
“The 9°C global warming will not appear in the Anthropocene at least till 2500 under the worst scenario,” Kaiho predicts.
Kaiho is not denying that many extinctions on land and in the sea are already occurring because of climate change; he just does not expect the same proportion of losses as before.
Still, it’s not just the degree of climate change that puts species at risk. The speed at which it occurs is vitally important.
The largest mass extinction event on Earth killed off 95 percent of known species at the time and occurred over 60,000 years about 250 million years ago. But today’s warming is occurring on a much shorter timescale thanks to human emissions of fossil fuels.
Perhaps more species will die off in Earth’s sixth extinction event not because the magnitude of warming is so great, but because the changes happened so quickly that many species could not adapt.
“Prediction of the future anthropogenic extinction magnitude using only surface temperature is difficult because the causes of the anthropogenic extinction differ from causes of mass extinctions in geologic time,” Kaihu admits.
Whichever way scientists slice up the data, it’s clear that many species are doomed unless we can halt climate change.
The exact percentage of losses and the timing of those losses remains up for debate.
The study was published in Biogeosciences.
An ‘Impossible’ Quasicrystal Was Created in The World’s First Nuclear Bomb Test
At 5:29 am on the morning of 16 July 1945, in the state of New Mexico, a dreadful slice of history was made.
The dawn calm was torn asunder as the United States Army detonated a plutonium implosion device known as the Gadget – the world’s very first test of a nuclear bomb, known as the Trinity test. This moment would change warfare forever.
The energy release, equivalent to 21 kilotons of TNT, vaporized the 30-meter test tower (98 ft) and miles of copper wires connecting it to recording equipment. The resulting fireball fused the tower and copper with the asphalt and desert sand below into green glass – a new mineral called trinitite.
Decades later, scientists discovered a secret hidden in a piece of that trinitite – a rare form of matter known as a quasicrystal, once thought to be impossible.
“Quasicrystals are formed in extreme environments that rarely exist on Earth,” geophysicist Terry Wallace of Los Alamos National Laboratory explained last year.
“They require a traumatic event with extreme shock, temperature, and pressure. We don’t typically see that, except in something as dramatic as a nuclear explosion.”
Most crystals, from the humble table salt to the toughest diamonds, obey the same rule: their atoms are arranged in a lattice structure that repeats in three-dimensional space. Quasicrystals break this rule – the pattern in which their atoms are arranged does not repeat.
When the concept first emerged in the scientific world in 1984, this was thought to be impossible: crystals were either ordered or disordered, with no in-between. Then they were actually found, both created in laboratory settings and in the wild – deep inside meteorites, forged by thermodynamic shock from events like a hypervelocity impact.
Knowing that extreme conditions are required to produce quasicrystals, a team of scientists led by geologist Luca Bindi of the University of Florence in Italy decided to take a closer look at trinitite.
But not the green stuff. Although they’re uncommon, we have seen enough quasicrystals to know that they tend to incorporate metals, so the team went looking for a much rarer form of the mineral – red trinitite, given its hue by the vaporized copper wires incorporated therein.
Using techniques such as scanning electron microscopy and X-ray diffraction, they analyzed six small samples of red trinitite. Finally, they got a hit in one of the samples – a tiny, 20-sided grain of silicon, copper, calcium and iron, with a five-fold rotational symmetry impossible in conventional crystals – an “unintended consequence” of warmongering.
“This quasicrystal is magnificent in its complexity – but nobody can yet tell us why it was formed in this way,” Wallace explained in 2021 when the team’s research was published.
“But someday, a scientist or engineer is going to figure that out and the scales will be lifted from our eyes and we will have a thermodynamic explanation for its creation. Then, I hope, we can use that knowledge to better understand nuclear explosions and ultimately lead to a more complete picture of what a nuclear test represents.”
This discovery represents the oldest known anthropogenic quasicrystal, and it suggests that there may be other natural pathways for the formation of quasicrystals. For example, the fulgurites of molten sand forged by lightning strikes, and material from meteor impact sites, could both be a source of quasicrystals in the wild.
The research could also help us better understand illicit nuclear tests, with the eventual aim of curbing the proliferation of nuclear armaments, the researchers said. Studying the minerals forged at other nuclear testing sites could uncover more quasicrystals, the thermodynamic properties of which could be a tool for nuclear forensics.
“Understanding other countries’ nuclear weapons requires that we have a clear understanding of their nuclear testing programs,” Wallace said.
“We typically analyze radioactive debris and gases to understand how the weapons were built or what materials they contained, but those signatures decay. A quasicrystal that is formed at the site of a nuclear blast can potentially tell us new types of information – and they’ll exist forever.”
The research has been published in PNAS.
Scientists Are Turning Dead Spiders Into ‘Necrobots’ And We Are So Creeped Out
When mechanical engineering graduate student Faye Yap saw a dead spider curled up in the hallway, it got her thinking about whether it could be used as a robotics component.
Turning dead spiders into mechanical grippers may be some people’s idea of a nightmare scenario, but it could have tangible benefits. Spider legs can grip large, delicate, and irregularly shaped objects firmly and softly without breaking them.
So, in collaboration with mechanical engineer Daniel Preston, Yap and her colleagues at Rice University discovered a way to make a dead wolf spider’s legs unfurl and grip onto objects.
They called this new type of robotics ‘necrobotics’.
Weirdly, spider legs don’t have muscles for extension, but instead move their legs via hydraulic pressure – they have what’s called a prosoma chamber, or cephalothorax, which contracts, sending inner body fluid into their legs, making them extend.
So, the team inserted a needle into the spider’s prosoma chamber and created a seal around the tip of the needle with a glob of superglue. Squeezing a tiny puff of air through the syringe was enough to activate the spider’s legs, achieving a full range of motion in less than one second.
“We took the spider, we placed the needle in it not knowing what was going to happen,” says Yap in a video on the Rice University website.
“We had an estimate of where we wanted to place the needle. And when we did, it worked, the first time, right off the bat. I don’t even know how to describe it, that moment.”
The team were able to make the dead spider grip onto a small ball and used that experiment to determine a peak grip force of 0.35 millinewtons.
They then demonstrated the use of a dead spider to pick up delicate objects and electronics, including having this necrobotic gripper remove a jumper wire attached to an electric breadboard and then move a block of polyurethane foam.
They also showed that the spider could bear the weight of another spider of about the same size.
(Preston Innovation Laboratory/Rice University)
Since spiders extend their legs by exerting hydraulic pressure from their cephalothorax, when they die the hydraulic system doesn’t work anymore. The flexor muscles in the spider’s legs go into rigor mortis, but, as the muscles only work in one direction, the spider curls up.
While most man-made robotics components are quite complex to manufacture, spiders are complex already and (unfortunately for arachnophobes) are in plentiful supply.
“The concept of necrobotics proposed in this work takes advantage of unique designs created by nature that can be complicated or even impossible to replicate artificially,” the researchers say in their paper.
Spiders are also biodegradable, so using them as robot parts would cut the amount of waste in robotics.
“One of the applications we could see this being used for is micro-manipulation, and that could include things like micro-electronic devices,” says Preston in the video.
One drawback to the dead spider gripper is that it starts to experience some wear and tear after two days or after 1,000 open-and-close cycles.
“We think that’s related to issues with dehydration of the joints. We think we can overcome that by applying polymeric coatings,” explains Preston.
The researchers experimented with coating the wolf spiders in beeswax and found that its mass decrease was 17 times less than the uncoated spider over 10 days, which meant it was retaining more water and its hydraulic system might function longer.
This study was published in Advanced Science.
NASA Reveals Ambitious New Plan to Detect Signs of Life on Distant Planets
NASA’s Institute for Advanced Concepts is famous for supporting outlandish ideas in the astronomy and space exploration fields. Since being re-established in 2011, the institute has supported a wide variety of projects as part of its three-phase program.
However, so far, only three projects have gone on to receive Phase III funding. And one of those just released a white paper describing a mission to get a telescope that could effectively see biosignatures on nearby exoplanets by utilizing the gravitational lens of our own Sun.
That Phase III distinction comes with US$2 million in funding, which in the case went to JPL, whose scientist, Slava Turyshev, was the principal investigator on the project’s first two phases.
He teamed up with The Aerospace corporation for this latest white paper, which describes a mission concept in more detail and defines what technologies already exist and what needs further development.
However, there are several striking features of this mission design, one of which is touched on in detail over at Centauri Dreams.
Instead of launching a large craft that would take a long time to travel anywhere, the proposed mission would launch several small cube-sats and then self-assemble on the 25-year journey out to the solar gravitational lens (SGL) point.
That “point” is actually a straight line between whatever star the exoplanet is around and somewhere between 550-1000 AU on the other side of the Sun. That is a tremendous distance, much further than the measly 156 AU that Voyager 1 has so far taken 44 years to traverse.
So how could a spacecraft get to three times the distance while taking almost half the time? Simple – it will dive (almost) into the Sun.
Using a gravitational boost from the Sun is a tried and true method. The fastest human-made object ever, the Parker Solar Probe, used just such a technique.
However, being boosted to 25 AU a year, the expected speed at which this mission would have to travel isn’t easy. And it would be even more challenging for a fleet of ships rather than just a single one.
The first problem would be material – solar sails, which are the mission’s preferred method of propulsion, don’t do so well when subjected to the intensity of the Sun that would be required for a gravitational slingshot.
In addition, the electronics on the system would have to be much more radiation hardened than currently existing tech. However, both of these known problems have potential solutions under active research.
Another seemingly obvious problem would be how to coordinate a passage of multiple satellites through this sort of gut-wrenching gravitational maneuver and still allow them to coordinate joining up to effectively form a fully functional spacecraft in the end.
But according to the paper’s authors, there will be more than enough time on the 25-year journey out to the observational point to actively rejoin the single Cubesats into a cohesive whole.
What could result from that cohesive whole is a better image of an exoplanet that humanity is likely to get short of a fully-fledged interstellar mission.
Which exoplanet would be the best candidate would be a topic of hot debate if the mission moves forward, as more than 50 so far have been found in the habitable zones of their stars. But that is certainly no guarantee as yet.
The mission hasn’t received any funding nor any indication that it will do so in the near future. And plenty of technologies would still have to be developed before such a mission would even be feasible.
But that is precisely how such missions always start, and this one has more potential impact than most. With luck, at some point in the next few decades, we would receive as crisp of an image of a potentially habitable exoplanet as we are likely to receive in the even medium future.
The team behind this research deserves praise for laying the groundwork for such an idea in the first place.
This article was originally published by Universe Today. Read the original article.
Study Suggests We Have This STI to Thank For The Evolution of Grandmothers
The arms race between the human immune system and gonorrhea might have had the useful side effect of promoting healthy brain tissue later in life.
This tiny boost to cognitive health in our twilight years might have played a small role in ensuring grandmas were sharp-minded enough for evolution to keep them around.
While it’s fiendishly difficult – and may be impossible – to figure out what evolutionary factors are responsible for living beyond ages where we no longer reproduce, researchers at the University of California, San Diego, are closing in on some possible explanations.
In 2015, a team of researchers led by molecular medicine professor Ajit Varki discovered that humans have a unique type of immune receptor that protects against Alzheimer’s disease and sets us apart from other primates.
In a paper published this month, the team found that the spreading of this variant immune receptor in our species wasn’t entirely random, but rather the result of intense selection pressure over a relatively brief period.
The research showed that some of our closest relatives – Neanderthals and Denisovans – did not have this version of immune receptors coded into their genomes. Something drove humans to develop this special immune receptor early in our history as a species, the researchers said.
The likely culprits are infectious human-specific pathogens like Neisseria gonorrhoeae that try to disguise themselves by dressing in the same sugar coating as human cells, which fools patrolling immune cells into thinking the bacteria are harmless.
Gonorrhea got very good at tricking the human immune system into thinking it was just another human cell. But the human immune system found a way to fight back.
The researchers showed that the newly evolved immune receptor could see through the disguise and kill the invading bacteria, while the older variation of the immune receptor could not.
Getting rid of gonorrhea is useful for the survival of the species because this disease can mess with human reproduction.
The new version of the immune receptor is called huCD33. Thanks to the way this version is tweaked into two subtly different structures within our body, it’s been the subject of investigations by evolutionary scientists for some time.
Once evolved, this immune receptor was probably co-oped by brain immune cells, called microglia, for a different purpose: protection against aging, the researchers suggest.
The human immune system usually doesn’t attack itself on purpose, but it needs to when cells start to decay.
The huCD33 receptor, which seems to have evolved as a response to sneaky bacteria, had the added benefit of being able to recognize decaying brain tissue and thereby protect cognitive function in old age.
Microglia use the huCD33 receptor to clear away damaged brain cells and amyloid plaques associated with Alzheimer’s disease. Whether this might have played a role in clearing the way for evolution to add a few more precious years to our lives for the sake of helping out with raising families is a topic open to debate.
Grandparents provide benefits to the human species as they help to look after kids and pass on important cultural knowledge. And gonorrhea may be to thank for that.
This paper was published in Molecular Biology and Evolution.