Astronomers have learned that the pull of gravity can sometimes overcome the strong magnetic fields found in great star-forming clouds in space. The resulting weakly magnetized gas flow can feed the growth of new stars.
Astronomers have known for decades that stars like our sun form when giant clouds of gas and dust in space – sometimes called molecular clouds – collapse under their own gravity. But how does the material from interstellar space flow into these clouds, and what controls the collapse? The image above helps illustrate an answer to these questions. It’s a composite, made with data from SOFIA – an airborne telescope designed for infrared astronomy – overlaid on an image from the now-retired Spitzer Space Telescope. This composite shows that the pull of gravity can sometimes overcome the strong magnetic fields found in great star-forming clouds in space. And it shows that, when that happens, weakly magnetized gas can flow – as on a conveyor belt – to feed the growth of newly forming star clusters.
A statement from the Max Planck Institute in Bonn, Germany, explained:
A major finding in the last decade has been that extensive networks of filaments permeate every molecular cloud. A picture has emerged that stars like our own sun form preferentially in dense clusters at the intersection of filaments.
Now look back at the image above, which shows the Serpens South star cluster, a star-forming region located some 1,400 light-years from Earth. In that image, you see a dark filament in the lower left. Now notice the “stripes” on the image, which astronomers call streamlines. They represent magnetic structures, discovered by SOFIA. The astronomers said these magnetic structures act like rivers, channeling material into the great star-forming cloud.
As you can see in the image, these magnetic streamlines have been dragged by gravity to align with the narrow, dark filament on the lower left. Astronomers say this configuration helps material from interstellar space flow into the cloud.
This is different from the upper parts of the image, where the magnetic fields are perpendicular to the filaments; in those regions, the magnetic fields in the cloud are opposing gravity.
The scientists said in a statement from Universities Space Research Association (USRA) that they are:
… studying the dense cloud to learn how magnetic fields, gravity and turbulent gas motions contribute to the creation of stars. Once thought to slow star birth by counteracting gravity, SOFIA’s data reveals magnetic fields may actually be working together with gravity as it pulls the fields into alignment with the filaments, nourishing the birth of stars.
The results were published in the peer-reviewed journal Nature Astronomy on August 17. The lead author of the new study is Thushara Pillai of Boston University and the Max Planck Institute for Radio Astronomy in Bonn, Germany.
In 1835, the French philosopher Auguste Comte wrote of the unknowable nature of stars:
On the subject of stars, all investigations which are not ultimately reducible to simple visual observations are … necessarily denied to us. While we can conceive of the possibility of determining their shapes, their sizes, and their motions, we shall never be able by any means to study their chemical composition or their mineralogical structure … Our knowledge concerning their gaseous envelopes is necessarily limited to their existence, size … and refractive power, we shall not at all be able to determine their chemical composition or even their density…
He was, famously, wrong.
He couldn’t have envisioned the range of tools available to modern astronomers. It’s a beautiful thing that, nowadays, astronomers can not only learn about the compositions of stars via their studies of their spectra, but also probe the deeper mysteries, going all the way to the births of these colossal, self-luminous balls in space.
Bottom line: Astronomers have learned that the pull of gravity can sometimes overcome the strong magnetic fields found in great star-forming clouds in space. The resulting weakly magnetized gas flow can feed the growth of new stars.
Just read that paragraph just before the end of the article: “He couldn’t have envisioned the range of tools available to modern astronomers. It’s a beautiful thing that, nowadays, astronomers can not only learn about the compositions of stars via their studies of their spectra, but also probe the deeper mysteries, going all the way to the births of these colossal, self-luminous balls in space.”
What a long way we have come from just, say, 50 years ago.
It would be easy to get lost in the article in a scientific manner, and that would be entirely appropriate.
But there’s another beautiful way to get lost in the article; by dreaming of outer space and forgetting just for a moment or two this Earthly planet we all live on!
I have been having some tiny problems mainly with the Apple Photos app and the good folks over at Ugly Hedgehog were incredibly helpful. This led to me taking my machine into Dick Webster Computers here in Grants Pass for a potential upgrade.
So I am going to republish some earlier posts for the next two days, which I hope will be long enough to come to a conclusion about whether this machine may be upgraded or whether I am looking at a new iMac.
I called in to Dick Webster, a good, local computer repair shop, earlier today. Took my iMac with me.
They told me that that particular iMac cannot have the RAM upgraded to 16GB but they could install a SSD. However, they looked up the Apple Photos app and said there were a number of complaints from others that it was freezing.
I was told to save my money, the iMac was perfectly good and to choose a photo editing application that supplied my needs.
My only outstanding query is whether all the relevant software programs, i.e. the photo editing apps, will run without any bother on 8GB.
There was such a good response to the article on the Hubble that I published on April 27th that it was an easy decision to republish the article that was presented on the BBC website on the 24th, and this time the photographs can be downloaded.
By Jonathan Amos, Science correspondent, 24 April 2020
It’s 30 years ago to the day that the Hubble telescope was launched – and to celebrate its birthday, the veteran observatory has produced another astonishing image of the cosmos.
This one is of a star-forming region close to our Milky Way Galaxy, about 163,000 light-years from Earth.
The larger object is the nebula NGC 2014; its companion is called NGC 2020.
But astronomers have nicknamed the scene the “Cosmic Reef” because it resembles an undersea world.
[There is an audio by Antonella Nota that is a little under 10 minutes long. I cannot embed it into this post for some unclear reason. Go here if you want to listen to it! It’s well worth listening to.]
Antonella Nota: “It’s called the people’s telescope because it brought the Universe to the people”
Famously blighted by blurred vision at the outset of its mission in 1990, Hubble was eventually repaired and upgraded.
The remarkable pictures it has taken of planets, stars, and galaxies have transformed our view of the cosmos.
Indeed, there are those who think Hubble is the most important scientific tool ever built.
It’s still far from retirement.
The US space agency (Nasa), which runs the observatory in partnership with the European Space Agency (Esa), says operations will be funded for as long as they remain productive.
Last year, its data resulted in almost 1,000 scientific papers being published – so it continues to stand at the forefront of discovery.
Engineers obviously keep a watching brief on the health of Hubble’s various systems. Pleasingly, all four instruments onboard – the two imagers and two spectrographs – work at full tilt.
In the past, the telescope’s Achilles heel has been the six gyroscopes that help turn and point the facility, maintaining a rock-steady gaze at targets on the sky.
These devices have periodically failed down the years, and during their final servicing mission in 2009 space shuttle astronauts were tasked with replacing all six.
Three have subsequently shut down again, but Nasa project scientist Dr Jennifer Wiseman says this is not yet an issue for serious concern.
“Nominally, we need three gyroscopes, but we can operate on just one due to the ingenuity of the engineers,” she asserted.
There’s a quiet confidence that Hubble can keep working well into the 2020s. Its supposed “successor” – the James Webb Space Telescope (JWST) – is due for launch next year, but the presence in orbit of this more modern observatory will in truth merely just extend capability; it won’t make Hubble redundant.
That’s because the new facility has been designed to see the cosmos at longer wavelengths of light than Hubble. The duo will be complementary and will on occasion actually pursue targets together to get a fuller perspective.
This is an exciting prospect for astronomers everywhere – but especially for those in Europe where Hubble has been such a rewarding endeavour, says Esa project scientist Dr Antonella Nota.
“From the memorandum of understanding there was a guarantee that European astronomers would get 15% of observing time for the duration of the mission. If I look back at how much time European astronomers got – on average it’s 22%. And it is a peer-reviewed process so we never needed to put a finger on the scales. European astronomers are creative; they’re smart; they’re doing leading-edge science,” she told BBC News.
What has Hubble contributed to science?
It’s a bit of a cliche, but Hubble has truly been a “discovery machine”.
Before the telescope launched in 1990, astronomers didn’t know whether the Universe was 10 billion years old or 20 billion years old.
Hubble’s survey of pulsating stars narrowed the uncertainty, and we now know the age extremely well, at 13.8 billion.
The observatory played a central role in revealing the accelerating expansion of the cosmos – a Nobel Prize-winning breakthrough – and it provided the definitive evidence for the existence of super-massive black holes at the centre of galaxies.
It’s amazing to think that when Hubble launched, scientists had yet to detect the first exoplanet, the name given to a planet orbiting a star other than our Sun. Today, Hubble is pioneering the study of these far-off worlds, examining their atmospheres to try to gauge their nature.
And although the sparkling eight-metre-class ground-based telescopes can now match – and even exceed – Hubble’s skill in certain fields of study, the space telescope remains peerless in going super-deep.
Its so-called Deep Field observations in which it stared at a small patch of sky for days on end to identify the existence of very distant, extremely faint galaxies is one of the towering achievements in astronomy.
These studies have shown us what the Universe was like just a few hundred million years after the Big Bang. Only JWST, with its finely-tuned infrared detectors, will go deeper still.
Kathryn Sullivan was one of the astronauts onboard Space Shuttle Discovery when it released Hubble into its 612km-high orbit on 25 April, 1990 – a day she recounts in a recent book, Handprints On Hubble.
“Hubble’s scientific impact has just been immense. But what I had not really appreciated until I started writing my book was the extent to which Hubble – because of its gorgeous images and their mind-bending implications – has really permeated popular culture,” she told BBC News.
“I see Hubble on the side of U-Haul (rental) trailers, on tattoos, on lunchboxes, on shirts, in advertisements, almost ubiquitously.
“And I think part of that is down to Hubble coming into service just as the internet was becoming the thing we now know it to be.
“That’s put the pictures right in front of people.”
This is the most amazing invention and regular missions to service the telescope including regular updates to the technology have kept it current.
It has produced the most distant and beautiful photographs. It has also refined our knowledge of when the universe came into existence – 13.8 billion years ago.
Today and tomorrow I am posting essays that have nothing to do with dogs! Today, I am sharing George’s gloom about the future, tomorrow I am sharing our human capacity for incredible ingenuity and technology.
Because I sense we are a species of two extremes; the very mad and the very clever!
I don’t have an answer but I can share these two essays.
Our legal action against the government aims to shut down fossil fuels
By George Monbiot, published in the Guardian 4th March 2020
Our survival is not an afterthought. The defence of the living planet cannot be tacked retrospectively onto business as usual. Yet this is how almost all governments operate. They slap the word “sustainable” on damaging projects they have already approved, then insist this means they’ve gone green. If we are to survive and prosper, everything must change. Every decision should begin with the question of what the planet can withstand.
This means that any discussion about new infrastructure should begin with ecological constraints. The figures are stark. A paper published in Nature last year showed that existing energy infrastructure, if it is allowed to run to the end of its natural life, will produce around 660 gigatonnes of CO2. Yet, to stand a reasonable chance of preventing more than 1.5°C of global heating, we can afford to release, in total, no more than 580 gigatonnes. In other words, far from building new fossil power plants, the survival of a habitable planet means retiring the damaging projects that have already been built. Electricity plants burning coal and gas and oil will not secure our prosperity. They will destroy it.
But everywhere special interests dominate. Construction projects are driven, above all, by the lobbying of the construction industry, consultancies and financiers. Gigantic and destructive schemes, such as the Oxford-Cambridge Expressway, are invented by lobbyists for the purpose of generating contracts. Political support is drummed up, the project achieves its own momentum, then, belatedly, a feeble attempt is made to demonstrate that it can somehow become compatible with environmental promises. This is what destroys civilisations: a mismatch between the greed of economic elites and the needs of society.
But last week, something momentous happened. The decision to build a scheme with vast financial backing and terrible environmental impacts was struck down by the Court of Appeal. The judges decided that government policy, on which planning permission for a third runway at Heathrow was based, had failed to take account of the UK’s climate commitments, and was therefore unlawful. This is – or should be – the end of business as usual.
On Tuesday, we delivered a “letter before action” to the Treasury solicitor. We’ve given the government 21 days to accept our case and change its policy to reflect the climate commitments agreed by Parliament. If it fails to do so, we shall issue proceedings in the High Court to have the policy declared unlawful. We’ll need money, so we’ve launched a crowdfunding appeal to finance the action.
It’s hard to see how the government could resist our case. The Heathrow judgement hung on the government’s national policy statement on airports. This, the judges found, had not been updated to take account of the Paris climate agreement. New fossil fuel plants, such as the gas burners at Drax in Yorkshire the government approved last October, are enabled by something very similar: the national policy statements on energy infrastructure. These have not been updated since they were published in 2011. As a result, they take no account of the Paris agreement, of the government’s new climate target (net zero by 2050, as opposed to an 80% cut) or of Parliament’s declaration of a climate emergency. The main policy statement says that the European Emissions Trading System “forms the cornerstone of UK action to reduce greenhouse gas emissions from the power sector”. As we have left the EU, this, obviously, no longer holds. The planning act obliges the government to review its national policy statements when circumstances change. It has failed to do so. It is disregarding its own laws.
These outdated policy statements create a presumption in favour of new fossil fuel plants. Once a national policy statement has been published, there is little objectors can do to prevent damaging projects from going ahead. In approving the Drax plant, the secretary of state for business and energy at the time (Andrea Leadsom) insisted that the policy statement came first, regardless of the climate impacts. Catastrophic decisions like this will continue to be made until the statements change. They are incompatible with either the government’s new climate commitments or a habitable planet.
While we are challenging the government’s energy policies, another group – the Transport Action Network – is about to challenge its road building schemes on the same basis. It points out that the national policy statement on road networks is also outdated and incompatible with the UK’s climate commitments. The policy statement, astonishingly, insists that “any increase in carbon emissions is not a reason to refuse development consent“, unless the increase is so great that the road would prevent the government from meeting its national targets. No single road project can be disqualified on these grounds. But the cumulative effect of new road building ensures that the UK will inevitably bust its carbon targets. While carbon emissions are officially disregarded, minuscule time savings are used to justify massive and damaging projects.
Transport emissions have been rising for the past five years, partly because of road building. The government tries to justify its schemes by claiming that cars will use less fossil fuel. But because they are becoming bigger and heavier, new cars sold in the UK now produce more carbon dioxide per kilometre than older models.
The perverse and outdated national policy statement locks into place such damaging projects as the A303 works around Stonehenge, the A27 Arundel scheme, the Lower Thames crossing, the Port of Liverpool access road, the Silvertown tunnel in London and the Wensum Link road in Norfolk. A government seeking to protect the lives of current and future generations would immediately strike down the policy that supports these projects, and replace it with one that emphasised walking, cycling and public transport.
A third action has been launched by Chris Packham and the law firm Leigh Day, challenging HS2 on similar grounds. Its carbon emissions were not properly taken into account, and its environmental impacts were assessed before the government signed the Paris agreement.
Already, the Heathrow decision is resonating around the world. Now we need to drive its implications home, by suing for survival. If we can oblige governments to resist the demands of corporate lobbyists and put life before profit, humanity might just stand a chance.
As I spoke about yesterday in my introduction, when my mother remarried my sister and I had a new man about the house, so to speak. He was Richard Mills.
I was 13 or thereabouts and already struggling with my school work (the result of my father’s sudden death). And ‘Dad’ as we called him was finding his feet in the strange world of going from having no children to instantly having two step children!
Anyway, Dad found a theme with me that I enjoyed: building a shortwave radio receiver. It was full of learning for me and over the years I became hooked on listening to radio stations both near and far transmitting in morse code. I also joined the Harrow Radio Society and went across to their weekly meetings by tube and bus. (Despite the Society no longer being at the Harrow address it is amazing that they are still going strong.)
It was also a time when there was a great deal of ‘radio surplus’ equipment going for next to nothing and I ‘upgraded’ to an R-1152 receiver.
In time I became sufficiently old to take driving lessons and pass my driving licence. I then got a secondhand car. It helped because then I could drive up to Bushey and spend Sunday mornings at the house of Ron Ray. Ron was a keen amateur. On Sunday mornings Ron had a small group of people who wanted to pass the morse code test and apply for a licence.
I was already a member of the RSGB, the Radio Society of Great Britain, and that surely encouraged me further to study for my amateur licence.
In time, I sat the exam and much to my amazement passed!
So that is the story of me and amateur radio.
Well, almost the full story.
In 1963 I volunteered for the Royal Naval Reserve, London Division. In time I was accepted and chose the join the radio branch, my G3PUK status coming in useful, because I reckoned that when we went to sea, on flat-bottomed minesweepers, it was better to be sick into a bucket between the knees than be sick on deck!
Two days of nostalgia follow! (You have been warned!)
As many of you already know, my father died fairly suddenly on December 20th, 1956. I had turned 12 some six weeks previously.
After about a year my mother remarried. His name was Richard Mills. Richard came to live at the house in Toley Avenue and had the unenviable task of taking on a new ‘son’ and ‘daughter’. (My sister, Elizabeth, some four years younger than I.)
Richard was a technical author in the newly-arrived electronics industry and one day he asked me if I would like to build a short-wave receiver. He coached me in the strange art of soldering wires and radio valves and other components and in the end I had a working receiver. That led, in turn, to me studying for an amateur radio licence. More of that tomorrow.
Simply elegant, Morse code marks 175 years and counting
The elegantly simple code works whether flashing a spotlight or blinking your eyes—or even tapping on a smartphone touchscreen
By Eddie King
Ph.D. Student in Electrical Engineering, University of South Carolina
May 21st, 2019
The first message sent by Morse code’s dots and dashes across a long distance traveled from Washington, D.C., to Baltimore on Friday, May 24, 1844 – 175 years ago. It signaled the first time in human history that complex thoughts could be communicated at long distances almost instantaneously. Until then, people had to have face-to-face conversations; send coded messages through drums, smoke signals and semaphore systems; or read printed words.
Thanks to Samuel F.B. Morse, communication changed rapidly, and has been changing ever faster since. He invented the electric telegraph in 1832. It took six more years for him to standardize a code for communicating over telegraph wires. In 1843, Congress gave him US$30,000 to string wires between the nation’s capital and nearby Baltimore. When the line was completed, he conducted a public demonstration of long-distance communication.
Morse wasn’t the only one working to develop a means of communicating over the telegraph, but his is the one that has survived. The wires, magnets and keys used in the initial demonstration have given way to smartphones’ on-screen keyboards, but Morse code has remained fundamentally the same, and is still – perhaps surprisingly – relevant in the 21st century. Although I have learned, and relearned, it many times as a Boy Scout, an amateur radio operator and a pilot, I continue to admire it and strive to master it.
Morse’s key insight in constructing the code was considering how frequently each letter is used in English. The most commonly used letters have shorter symbols: “E,” which appears most often, is signified by a single “dot.” By contrast, “Z,” the least used letter in English, was signified by the much longer and more complex “dot-dot-dot (pause) dot.”
In 1865, the International Telecommunications Union changed the code to account for different character frequencies in other languages. There have been other tweaks since, but “E” is still “dot,” though “Z” is now “dash-dash-dot-dot.”
The reference to letter frequency makes for extremely efficient communications: Simple words with common letters can be transmitted very quickly. Longer words can still be sent, but they take more time.
The communications system that Morse code was designed for – analogue connections over metal wires that carried a lot of interference and needed a clear on-off type signal to be heard – has evolved significantly.
The first big change came just a few decades after Morse’s demonstration. In the late 19th century, Guglielmo Marconi invented radio-telegraph equipment, which could send Morse code over radio waves, rather than wires.
The shipping industry loved this new way to communicate with ships at sea, either from ship to ship or to shore-based stations. By 1910, U.S. law required many passenger ships in U.S. waters to carry wireless sets for sending and receiving messages.
Aviators also use Morse code to identify automated navigational aids. These are radio beacons that help pilots follow routes, traveling from one transmitter to the next on aeronautical charts. They transmit their identifiers – such as “BAL” for Baltimore – in Morse code. Pilots often learn to recognize familiar-sounding patterns of beacons in areas they fly frequently.
There is a thriving community of amateur radio operators who treasure Morse code, too. Among amateur radio operators, Morse code is a cherished tradition tracing back to the earliest days of radio. Some of them may have begun in the Boy Scouts, which has made learning Morse variably optional or required over the years. The Federal Communications Commission used to require all licensed amateur radio operators to demonstrate proficiency in Morse code, but that ended in 2007. The FCC does still issue commercial licenses that require Morse proficiency, but no jobs require it anymore.
Because its signals are so simple – on or off, long or short – Morse code can also be used by flashing lights. Many navies around the world use blinker lights to communicate from ship to ship when they don’t want to use radios or when radio equipment breaks down. The U.S. Navy is actually testing a system that would let a user type words and convert it to blinker light. A receiver would read the flashes and convert it back to text.
Perhaps the most notable modern use of Morse code was by Navy pilot Jeremiah Denton, while he was a prisoner of war in Vietnam. In 1966, about one year into a nearly eight-year imprisonment, Denton was forced by his North Vietnamese captors to participate in a video interview about his treatment. While the camera focused on his face, he blinked the Morse code symbols for “torture,” confirming for the first time U.S. fears about the treatment of service members held captive in North Vietnam.
Navy pilot Jeremiah Denton, a prisoner of war, blinks Morse code spelling out ‘torture’ during a forced interview with his captors.
There are still many ways people can learn Morse code, and practice using it, even online. In emergency situations, it can be the only mode of communications that will get through. Beyond that, there is an art to Morse code, a rhythmic, musical fluidity to the sound. Sending and receiving it can have a soothing or meditative feeling, too, as the person focuses on the flow of individual characters, words and sentences. Overall, sometimes the simplest tool is all that’s needed to accomplish the task.
I do hope you read this article in full because it contains much interesting information. Many people will not have a clue about The Morse Code and, as you can see above, it is still relevant.
Finally, I can still remember the The Morse Code after all these years!
Science confirms what we instinctively understand!
That the way a dog looks deep into our eyes is more than emotional froth!
Follower of this blog, Anita, left a comment to yesterday’s post. This is what she wrote (my emphasis):
This has been a wonderful compilation of awesome photos. You must do it again sometime. Dogs are so wonderful and such great companions. They do have eyes that see straight through our very souls and ready to love us at the drop of a hat.
One of our dogs here at home, Oliver, has those eyes. When he stares into my own eyes it feels as though at some mystical level Oliver and I are connected.
So imagine my surprise when reading yesterday the lead essay in The Smithsonian about the evolution of the domesticated dog and me coming across this:
The relationship has become so close that even our brains are in sync. Witness a study showing that dogs hijack the human brain’s maternal bonding system. When humans and dogs gaze lovingly into one another’s eyes, each of their brains secretes oxytocin, a hormone linked to maternal bonding and trust.
In other words, science confirms what I experience as being real!! (Undoubtedly shared by many of you!)
Long ago, before your four-legged best friend learned to fetch tennis balls or watch football from the couch, his ancestors were purely wild animals in competition—sometimes violent—with our own. So how did this relationship change? How did dogs go from being our bitter rivals to our snuggly, fluffy pooch pals?
The new drama Alpha answers that question with a Hollywood “tail” of the very first human/dog partnership.
Europe is a cold and dangerous place 20,000 years ago when the film’s hero, a young hunter named Keda, is injured and left for dead. Fighting to survive, he forgoes killing an injured wolf and instead befriends the animal, forging an unlikely partnership that—according to the film—launches our long and intimate bond with dogs.
Just how many nuggets of fact might be sprinkled throughout this prehistoric fiction?
We’ll never know the gritty details of how humans and dogs first began to come together. But beyond the theater the true story is slowly taking shape, as scientists explore the real origins of our oldest domestic relationship and learn how both species have changed along canines’ evolutionary journey from wolves to dogs.
When and where were dogs domesticated?
Pugs and poodles may not look the part, but if you trace their lineages far enough back in time all dogs are descended from wolves. Gray wolves and dogs diverged from an extinct wolf species some 15,000 to 40,000 years ago. There’s general scientific agreement on that point, and also with evolutionary anthropologist Brian Hare’s characterization of what happened next. ’The domestication of dogs was one of the most extraordinary events in human history,” Hare says.
But controversies abound concerning where a long-feared animal first became our closest domestic partner. Genetic studies have pinpointed everywhere from southern China to Mongolia to Europe.
Scientists cannot agree on the timing, either. Last summer, research reported in Nature Communications pushed likely dates for domestication further back into the past, suggesting that dogs were domesticated just once at least 20,000 but likely closer to 40,000 years ago. Evolutionary ecologist Krishna R. Veeramah, of Stony Brook University, and colleagues sampled DNA from two Neolithic German dog fossils, 7,000 and 4,700 years old respectively. Tracing genetic mutation rates in these genomes yielded the new date estimates.
“We found that our ancient dogs from the same time period were very similar to modern European dogs, including the majority of breed dogs people keep as pets,” explained Dr. Veeramah in a release accompanying the study. This suggests, he adds, “that there was likely only a single domestication event for the dogs observed in the fossil record from the Stone Age and that we also see and live with today.”
Comparing these genomes with many wolves and modern dog breeds suggested that dogs were domesticated in Asia, at least 14,000 years ago, and their lineages split some 14,000 to 6,400 years ago into East Asian and Western Eurasian dogs .
But because dog fossils apparently older than these dates have been found in Europe, the authors theorize that wolves may have been domesticated twice, though the European branch didn’t survive to contribute much to today’s dogs. Greger Larson, director of the Wellcome Trust Palaeogenomics & Bio-Archaeology Research Network at Oxford University, suggests that the presence of older fossils in both Europe and Asia, and the lack of dogs older than 8,000 years in between those regions, supports such a scenario.
“Our ancient DNA evidence, combined with the archaeological record of early dogs, suggests that we need to reconsider the number of times dogs were domesticated independently. Maybe the reason there hasn’t yet been a consensus about where dogs were domesticated is because everyone has been a little bit right,′ Larson said in a statement accompanying the study.
Perhaps more intriguing than exactly when or where dogs became domesticated is the question of how. Was it really the result of a solitary hunter befriending an injured wolf? That theory hasn’t enjoyed much scientific support.
One similar theory argues that early humans somehow captured wolf pups, kept them as pets, and gradually domesticated them. This could have happened around the same time as the rise of agriculture, about 10,000 years ago. The oldest fossils generally agreed to be domestic dogs date to about 14,000 years, but several disputed fossils more than twice that age may also be dogs or at least their no longer entirely wolf ancestors.
Since more recent genetic studies suggest that the date of domestication occurred far earlier, a different theory has gained the support of many scientists. “Survival of the friendliest” suggests that wolves largely domesticated themselves among hunter-gatherer people.
“That the first domesticated animal was a large carnivore, who would have been a competitor for food—anyone who has spent time with wild wolves would see how unlikely it was that we somehow tamed them in a way that led to domestication,” says Brian Hare, director of the Duke University Canine Cognition Center.
But, Hare notes, the physical changes that appeared in dogs over time, including splotchy coats, curly tails, and floppy ears, follow a pattern of a process known as self-domestication. It’s what happens when the friendliest animals of a species somehow gain an advantage. Friendliness somehow drives these physical changes, which can begin to appear as visible byproducts of this selection in only a few generations.
“Evidence for this comes from another process of domestication, one involving the famous case of domesticated foxes in Russia. This experiment bred foxes who were comfortable getting close to humans, but researchers learned that these comfortable foxes were also good at picking up on human social cues,” explains Laurie Santos, director of the Canine Cognition Center at Yale University. The selection of social foxes also had the unintended consequence of making them look increasingly adorable—like dogs.
Hare adds that most wolves would have been fearful and aggressive towards humans—because that’s the way most wolves behave. But some would have been friendlier, which may have given them access to human hunter-gatherer foodstuffs..
“These wolves would have had an advantage over other wolves, and the strong selection pressure on friendliness had a whole lot of byproducts, like the physical differences we see in dogs,” he says. “This is self-domestication. We did not domesticate dogs. Dogs domesticated themselves.”
A study last year provided some possible genetic support for this theory. Evolutionary biologist Bridgette von Holdt, of Princeton University, and colleagues suggest that hypersocial behavior may have linked our two species and zero in on a few genes that may drive that behavior.
“Generally speaking, dogs display a higher level of motivation than wolves to seek out prolonged interactions with humans. This is the behavior I’m interested in,” she says.
Von Holdt’s research shows that the social dogs she tested have disruption to a genomic region that remains intact in more aloof wolves. Interestingly, in humans genetic variation in the same stretch of DNA causes Williams-Beuren syndrome, a condition characterized by exceptionally trusting and friendly behaviors. Mice also become more social if changes occur to these genes, previous studies have discovered.
The results suggest that random variations to these genes, with others yet unknown, may have played a role in causing some dogs to first cozy up with humans.
“We were able to identify one of the many molecular features that likely shape behavior,” she adds.
How have dogs changed since becoming our best friends?
Though the origins of the dog/human partnership remain unknown, it’s becoming increasingly clear that each species has changed during our long years together. The physical differences between a basset hound and wolf are obvious, but dogs have also changed in ways that are more than skin (or fur) deep.
But, Yale’s Laurie Santos says, dogs may have compensated in other interesting ways. They’ve learned to use humans to solve problems.
“Several researchers have presented dogs and wolves with an impossible problem (e.g., a puzzle box that can’t be opened or a pulling tool that stops working) and have asked how these different species react,” Santos explains. “Researchers have found that wolves try lots of different trial and error tactics to solve the problem— they get at it physically. But at the first sign of trouble, dogs do something different. They look back to their human companion for help. This work hints that dogs may have lost some of their physical problem-solving abilities in favor of more social strategies, ones that rely on the unique sort of cooperation domesticated dogs have with humans. This also matches the work showing that dogs are especially good at using human social cues.”
The relationship has become so close that even our brains are in sync. Witness a study showing that dogs hijack the human brain’s maternal bonding system. When humans and dogs gaze lovingly into one another’s eyes, each of their brains secretes oxytocin, a hormone linked to maternal bonding and trust. Other mammal relationships, including those between mom and child, or between mates, feature oxytocin bonding, but the human/dog example is the only case in which it has been observed at work between two different species.
The intimacy of this relationship means that, by studying dogs, we may also learn much about human cognition.
We may never know the exact story of how the first dogs and humans joined forces, but dogs have undoubtedly helped us in countless ways over the years. Still, only now may we be realizing that by studying them, they can help us to better understand ourselves.
I can do no better than to repeat those last two sentences of the essay by Brian Handwerk:
We may never know the exact story of how the first dogs and humans joined forces, but dogs have undoubtedly helped us in countless ways over the years. Still, only now may we be realizing that by studying them, they can help us to better understand ourselves.
For, boy of boy, do we humans need help when it comes to better understanding ourselves!
In gratitude to Roger Davis, long-time friend from my UK days, who forwarded me the link to the following. (Caution, the video does contain some coarse language probably unsuitable for those below the age of 16.)