Tag: The Conversation

Our human language!

Namely a universal law.

I was attracted to an article that I read in The Conversation last a week ago.

It also taught me that we humans speak according to Zipf’s Law. I had not previously heard of this law.

So let me republish the article with the full permission of The Conversation.

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Whalesong patterns follow a universal law of human language, new research finds

A humpback whale mother and calf on the New Caledonian breeding grounds. Mark Quintin

Jenny Allen, Griffith University; Ellen Garland, University of St Andrews; Inbal Arnon, Hebrew University of Jerusalem, and Simon Kirby, University of Edinburgh

All known human languages display a surprising pattern: the most frequent word in a language is twice as frequent as the second most frequent, three times as frequent as the third, and so on. This is known as Zipf’s law.

Researchers have hunted for evidence of this pattern in communication among other species, but until now no other examples have been found.

In new research published today in Science, our team of experts in whale song, linguistics and developmental psychology analysed eight years’ of song recordings from humpback whales in New Caledonia. Led by Inbal Arnon from the Hebrew University, Ellen Garland from the University of St Andrews, and Simon Kirby from the University of Edinburgh, We used techniques inspired by the way human infants learn language to analyse humpback whale song.

We discovered that the same Zipfian pattern universally found across human languages also occurs in whale song. This complex signalling system, like human language, is culturally learned by each individual from others.

Learning like an infant

When infant humans are learning, they have to somehow discover where words start and end. Speech is continuous and does not come with gaps between words that they can use. So how do they break into language?

Thirty years of research has revealed that they do this by listening for sounds that are surprising in context: sounds within words are relatively predictable, but between words are relatively unpredictable. We analysed the whale song data using the same procedure.

Photo of a humpback whale breaching from the water.
A breaching humpback whale in New Caledonia. Operation Cetaces

Unexpectedly, using this technique revealed in whale song the same statistical properties that are found in all languages. It turns out both human language and whale song have statistically coherent parts.

In other words, they both contain recurring parts where the transitions between elements are more predictable within the part. Moreover, these recurring sub-sequences we detected follow the Zipfian frequency distribution found across all human languages, and not found before in other species.

Whale song recording (2017) Operation Cetaces 916 KB (download)

A chart showing the different frequencies of sound in whale song.
Close analysis of whale song revealed statistical structures similar to those found in human language. Operation Cetaces

How do the same statistical properties arise in two evolutionarily distant species that differ from one another in so many ways? We suggest we found these similarities because humans and whales share a learning mechanism: culture.

A cultural origin

Our findings raise an exciting question: why would such different systems in such incredibly distant species have common structures? We suggest the reason behind this is that both are culturally learned.

Cultural evolution inevitably leads to the emergence of properties that make learning easier. If a system is hard to learn, it will not survive to the next generation of learners.

There is growing evidence from experiments with humans that having statistically coherent parts, and having them follow a Zipfian distribution, makes learning easier. This suggests that learning and transmission play an important role in how these properties emerged in both human language and whale song.

So can we talk to whales now?

Finding parallel structures between whale song and human language may also lead to another question: can we talk to whales now? The short answer is no, not at all.

Our study does not examine the meaning behind whale song sequences. We have no idea what these segments might mean to the whales, if they mean anything at all.

Photo of whale backs and tails visible above the surface of the sea.
A competitive pod of humpback whales on the New Caledonian breeding grounds. Operation Cetaces

It might help to think about it like instrumental music, as music also contains similar structures. A melody can be learned, repeated, and spread – but that doesn’t give meaning to the musical notes in the same way that individual words have meaning.

Next up: birdsong

Our work also makes a bold prediction: we should find this Zipfian distribution wherever complex communication is transmitted culturally. Humans and whales are not the only species that do this.

We find what is known as “vocal production learning” in an unusual range of species across the animal kingdom. Song birds in particular may provide the best place to look as many bird species culturally learn their songs, and unlike in whales, we know a lot about precisely how birds learn song.

Equally, we expect not to find these statistical properties in the communication of species that don’t transmit complex communication by learning. This will help to reveal whether cultural evolution is the common driver of these properties between humans and whales.

Jenny Allen, Postdoctoral research associate, Griffith University; Ellen Garland, Royal Society University Research Fellow, School of Biology, University of St Andrews; Inbal Arnon, Professor of Psychology, Hebrew University of Jerusalem, and Simon Kirby, Professor of Language Evolution, University of Edinburgh

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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The research scientists have led to a prediction: … we should find this Zipfian distribution wherever complex communication is transmitted culturally. Humans and whales are not the only species that do this.

Fascinating!

Nutrition advice

An article on educating us on avoiding misinformation.

Many articles on nutrition are full of errors and for the lay person there’s no easy way to understand what is correct, or not.

That’s why a recent article appealed to me and I thought it worth sharing.

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Nutrition advice is rife with misinformation − a medical education specialist explains how to tell valid health information from pseudoscience

If a health claim about a dietary intervention sounds too good to be true, it probably is. Mizina/iStock via Getty Images Plus

Aimee Pugh Bernard, University of Colorado Anschutz Medical Campus

The COVID-19 pandemic illuminated a vast landscape of misinformation about many topics, science and health chief among them.

Since then, information overload continues unabated, and many people are rightfully confused by an onslaught of conflicting health information. Even expert advice is often contradictory.

On top of that, people sometimes deliberately distort research findings to promote a certain agenda. For example, trisodium phosphate is a common food additive in cakes and cookies that is used to improve texture and prevent spoilage, but wellness influencers exploit the fact that a similarly named substance is used in paint and cleaning products to suggest it’s dangerous to your health.

Such claims can proliferate quickly, creating widespread misconceptions and undermining trust in legitimate scientific research and medical advice. Social media’s rise as a news and information source further fuels the spread of pseudoscientific views.

Misinformation is rampant in the realm of health and nutrition. Findings from nutrition research is rarely clear-cut because diet is just one of many behaviors and lifestyle factors affecting health, but the simplicity of using food and supplements as a cure-all is especially seductive.

I am an assistant professor specializing in medical education and science communication. I also train scientists and future health care professionals how to communicate their science to the general public.

In my view, countering the voices of social media influencers and health activists promoting pseudoscientific health claims requires leaning into the science of disease prevention. Extensive research has produced a body of evidence-based practices and public health measures that have consistently been shown to improve the health of millions of people around the world. Evaluating popular health claims against the yardstick of this work can help distinguish which ones are based on sound science.

A white person's hands holding a smartphone with screen showing a health app, next to a cup of coffee.
To parse pseudoscientific claims from sound advice about health and nutrition, it’s crucial to evaluate the information’s source. tadamichi/Getty Images

Navigating the terrain of tangled information

Conflicting information can be found on just about everything we eat and drink.

That’s because a food or beverage is rarely just good or bad. Instead, its health effects can depend on everything from the quantity a person consumes to their genetic makeup. Hundreds of scientific studies describe coffee’s health benefits and, on the flip side, its health risks. A bird’s-eye view can point in one direction or another, but news articles and social media posts often make claims based on a single study.

Things can get even more confusing with dietary supplements because people who promote them often make big claims about their health benefits. Take apple cider vinegar, for example – or ACV, if you’re in the know.

Apple cider vinegar has been touted as an all-natural remedy for a variety of ailments, including digestive issues, urinary health and weight management. Indeed, some studies have shown that it might help lower cholesterol, in addition to having other health benefits, but overall those studies have small sample sizes and are inconclusive.

Advocates of this substance often claim that one particular component of it – the cloudy sediment at the bottom of the bottle termed “the mother” – is especially beneficial because of the bacteria and yeast it contains. But there is no research that backs the claim that it offers any health benefits.

One good rule of thumb is that health hacks that promise quick fixes are almost always too good to be true. And even when supplements do offer some health benefits under specific circumstances, it’s important to remember that they are largely exempt from Food and Drug Administration regulations. That means the ingredients on their labels might contain more or less of the ingredients promised or other ingredients not listed, which can potentially cause harms such as liver toxicity.

It’s also important to keep in mind that the global dietary supplements industry is worth more than US$150 billion per year, so companies – and wellness influencers – selling supplements have a financial stake in convincing the public of their value.

Misinformation about nutrition is nothing new, but that doesn’t make it any less confusing.

How nutrition science gets twisted

There’s no doubt that good nutrition is fundamental for your health. Studies consistently show that a balanced diet containing a variety of essential nutrients can help prevent chronic diseases and promote overall well-being.

For instance, minerals such as calcium and iron support bone health and oxygen circulation in the blood, respectively. Proteins are essential for muscle repair and growth, and healthy fats, like those found in avocados and nuts, are vital for brain health.

However, pseudoscientific claims often twist such basic facts to promote the idea that specific diets or supplements can prevent or treat illness. For example, vitamin C is known to play a role in supporting the immune system and can help reduce the duration and severity of colds.

But despite assertions to the contrary, consuming large quantities of vitamin C does not prevent colds. In fact, the body needs only a certain amount of vitamin C to function properly, and any excess is simply excreted.

Companies sometimes claim their supplement is “scientifically proven” to cure illness or boost brain function, with no credible research to back it up.

Some companies overstate the benefits while underplaying the hazards.

For example, wellness influencers have promoted raw milk over pasteurized milk as a more natural and nutritious choice, but consuming it is risky. Unpasteurized milk can contain harmful bacteria that leads to gastrointestinal illness and, in some cases, much more serious and potentially life-threatening diseases such as avian influenza, or bird flu.

Such dietary myths aren’t harmless. Reliance on nutrition alone can lead to neglecting other critical aspects of health, such as regular medical checkups and lifesaving vaccinations.

The lure of dietary myths has led people with cancer to replace proven science-backed treatments, such as chemotherapy or radiation, with unproven and misleading nutrition programs.

How to spot less-than-solid science

Pseudoscience exploits your insecurities and emotions, taking advantage of your desire to live the healthiest life possible.

While the world around you may be uncertain and out of your control, you want to believe that at the very least, you have control over your own health. This is where the wellness industry steps in.

What makes pseudoscientific claims so confusing is that they use just enough scientific jargon to sound believable. Supplements or powders that claim to “boost immunity” often list ingredients such as adaptogens and superfoods. While these words sound real and convincing, they actually don’t mean anything in science. They are terms created by the wellness industry to sell products.

I’ve researched and written about reliable ways to distinguish science facts from false health claims. To stay alert and find credible information, I’d suggest you follow a few key steps.

First, check your emotions – strong emotional reactions, such as fear and anger, can be a red flag.

Next, check that the author has experience or expertise in the field of the topic. If they’re not an expert, they might not know what they are talking about. It’s always a good idea to make sure the source is reputable – ask yourself, would this source be trusted by scientists?

Finally, search for references that back up the information. If very little or nothing else exists in the science world to back up the claims, you may want to put your trust in a different source.

Following these steps will separate the facts from fake news and empower you to make evidence-based decisions.

Aimee Pugh Bernard, Assistant Professor of Immunology and Microbiology, University of Colorado Anschutz Medical Campus

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Sound advice for the majority of us!

The Edwin Hubble Great Debate

The following is more than fascinating; it is an example of how far science has reached; both figuratively and literally.

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One large Milky Way galaxy or many galaxies? 100 years ago, a young Edwin Hubble settled astronomy’s ‘Great Debate’

The Andromeda galaxy helped Edwin Hubble settle a great debate in astronomy. Stocktrek Images via Getty Images

Chris Impey, University of Arizona

A hundred years ago, astronomer Edwin Hubble dramatically expanded the size of the known universe. At a meeting of the American Astronomical Society in January 1925, a paper read by one of his colleagues on his behalf reported that the Andromeda nebula, also called M31, was nearly a million light years away – too remote to be a part of the Milky Way.

Hubble’s work opened the door to the study of the universe beyond our galaxy. In the century since Hubble’s pioneering work, astronomers like me have learned that the universe is vast and contains trillions of galaxies.

Nature of the nebulae

In 1610, astronomer Galileo Galilei used the newly invented telescope to show that the Milky Way was composed of a huge number of faint stars. For the next 300 years, astronomers assumed that the Milky Way was the entire universe.

As astronomers scanned the night sky with larger telescopes, they were intrigued by fuzzy patches of light called nebulae. Toward the end of the 18th century, astronomer William Herschel used star counts to map out the Milky Way. He cataloged a thousand new nebulae and clusters of stars. He believed that the nebulae were objects within the Milky Way.

Charles Messier also produced a catalog of over 100 prominent nebulae in 1781. Messier was interested in comets, so his list was a set of fuzzy objects that might be mistaken for comets. He intended for comet hunters to avoid them since they did not move across the sky.

As more data piled up, 19th century astronomers started to see that the nebulae were a mixed bag. Some were gaseous, star-forming regions, such as the Orion nebula, or M42 – the 42nd object in Messier’s catalog – while others were star clusters such as the Pleiades, or M45.

A third category – nebulae with spiral structure – particularly intrigued astronomers. The Andromeda nebula, M31, was a prominent example. It’s visible to the naked eye from a dark site.

The Andromeda galaxy, then known as the Andromeda nebula, is a bright spot in the sky that intrigued early astronomers.

Astronomers as far back as the mid-18th century had speculated that some nebulae might be remote systems of stars or “island universes,” but there was no data to support this hypothesis. Island universes referred to the idea that there could be enormous stellar systems outside the Milky Way – but astronomers now just call these systems galaxies.

In 1920, astronomers Harlow Shapley and Heber Curtis held a Great Debate. Shapley argued that the spiral nebulae were small and in the Milky Way, while Curtis took a more radical position that they were independent galaxies, extremely large and distant.

At the time, the debate was inconclusive. Astronomers now know that galaxies are isolated systems of stars, much smaller than the space between them.

Hubble makes his mark

Edwin Hubble was young and ambitious. At the of age 30, he arrived at Mount Wilson Observatory in Southern California just in time to use the new Hooker 100-inch telescope, at the time the largest in the world.

A black and white photo of a man looking through the lens of a large telescope.
Edwin Hubble uses the telescope at the Mount Wilson Observatory. Hulton Archives via Getty Images

He began taking photographic plates of the spiral nebulae. These glass plates recorded images of the night sky using a light-sensitive emulsion covering their surface. The telescope’s size let it make images of very faint objects, and its high-quality mirror allowed it to distinguish individual stars in some of the nebulae.

Estimating distances in astronomy is challenging. Think of how hard it is to estimate the distance of someone pointing a flashlight at you on a dark night. Galaxies come in a very wide range of sizes and masses. Measuring a galaxy’s brightness or apparent size is not a good guide to its distance.

Hubble leveraged a discovery made by Henrietta Swan Leavitt 10 years earlier. She worked at the Harvard College Observatory as a “human computer,” laboriously measuring the positions and brightness of thousands of stars on photographic plates.

She was particularly interested in Cepheid variables, which are stars whose brightness pulses regularly, so they get brighter and dimmer with a particular period. She found a relationship between their variation period, or pulse, and their intrinsic brightness or luminosity.

Once you measure a Cepheid’s period, you can calculate its distance from how bright it appears using the inverse square law. The more distant the star is, the fainter it appears.

Hubble worked hard, taking images of spiral nebulae every clear night and looking for the telltale variations of Cepheid variables. By the end of 1924, he had found 12 Cepheids in M31. He calculated M31’s distance as a prodigious 900,000 light years away, though he underestimated its true distance – about 2.5 million light years – by not realizing there were two different types of Cepheid variables.

His measurements marked the end of the Great Debate about the Milky Way’s size and the nature of the nebulae. Hubble wrote about his discovery to Harlow Shapley, who had argued that the Milky Way encompassed the entire universe.

“Here is the letter that destroyed my universe,” Shapley remarked.

Always eager for publicity, Hubble leaked his discovery to The New York Times five weeks before a colleague presented his paper at the astronomers’ annual meeting in Washington, D.C.

An expanding universe of galaxies

But Hubble wasn’t done. His second major discovery also transformed astronomers’ understanding of the universe. As he dispersed the light from dozens of galaxies into a spectrum, which recorded the amount of light at each wavelength, he noticed that the light was always shifted to longer or redder wavelengths.

Light from the galaxy passes through a prism or reflects off a diffraction grating in a telescope, which captures the intensity of light from blue to red.

Astronomers call a shift to longer wavelengths a redshift.

It seemed that these redshifted galaxies were all moving away from the Milky Way.

Hubble’s results suggested the farther away a galaxy was, the faster it was moving away from Earth. Hubble got the lion’s share of the credit for this discovery, but Lowell Observatory astronomer Vesto Slipher, who noticed the same phenomenon but didn’t publish his data, also anticipated that result.

Hubble referred to galaxies having recession velocities, or speeds of moving away from the Earth, but he never figured out that they were moving away from Earth because the universe is getting bigger.

Belgian cosmologist and Catholic priest Georges Lemaitre made that connection by realizing that the theory of general relativity described an expanding universe. He recognized that space expanding in between the galaxies could cause the redshifts, making it seem like they were moving farther away from each other and from Earth.

Lemaitre was the first to argue that the expansion must have begun during the big bang.

The Hubble telescope, which looks like a metal cylinder, floating in space.
Edwin Hubble is the namesake for NASA’s Hubble Space Telescope, which has spent decades observing faraway galaxies. NASA via AP

NASA named its flagship space observatory after Hubble, and it has been used to study galaxies for 35 years. Astronomers routinely observe galaxies that are thousands of times fainter and more distant than galaxies observed in the 1920s. The James Webb Space Telescope has pushed the envelope even farther.

The current record holder is a galaxy a staggering 34 billion light years away, seen just 200 million years after the big bang, when the universe was 20 times smaller than it is now. Edwin Hubble would be amazed to see such progress.

Chris Impey, University Distinguished Professor of Astronomy, University of Arizona

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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So wonderful that in this modern era we can read articles from distinguished scientists in the comfort of our own homes.

The geological history of Planet Earth

We live on a profoundly ancient and beautiful planet.

I follow the photographic website Ugly Hedgehog and have been doing for some time. There has been a post recently from the section Photo Gallery and ‘greymule’ from Colorado called his entry ‘A Couple of Desert Scenes’ and I will display just one of his images from that post.

It makes a wonderful connection to today’s post which is from The Conversation.

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Evidence from Snowball Earth found in ancient rocks on Colorado’s Pikes Peak – it’s a missing link

Rocks can hold clues to history dating back hundreds of millions of years. Christine S. Siddoway

Liam Courtney-Davies, University of Colorado Boulder; Christine Siddoway, Colorado College, and Rebecca Flowers, University of Colorado Boulder

Around 700 million years ago, the Earth cooled so much that scientists believe massive ice sheets encased the entire planet like a giant snowball. This global deep freeze, known as Snowball Earth, endured for tens of millions of years.

Yet, miraculously, early life not only held on, but thrived. When the ice melted and the ground thawed, complex multicellular life emerged, eventually leading to life-forms we recognize today.

The Snowball Earth hypothesis has been largely based on evidence from sedimentary rocks exposed in areas that once were along coastlines and shallow seas, as well as climate modeling. Physical evidence that ice sheets covered the interior of continents in warm equatorial regions had eluded scientists – until now.

In new research published in the Proceedings of the National Academy of Sciences, our team of geologists describes the missing link, found in an unusual pebbly sandstone encapsulated within the granite that forms Colorado’s Pikes Peak.

An illustration of an icy earth viewed from space
Earth iced over during the Cryogenian Period, but life on the planet survived. NASA illustration

Solving a Snowball Earth mystery on a mountain

Pikes Peak, originally named Tavá Kaa-vi by the Ute people, lends its ancestral name, Tava, to these notable rocks. They are composed of solidified sand injectites, which formed in a similar manner to a medical injection when sand-rich fluid was forced into underlying rock.

A possible explanation for what created these enigmatic sandstones is the immense pressure of an overlying Snowball Earth ice sheet forcing sediment mixed with meltwater into weakened rock below.

A hand holds a rock with dark seams through it and other colors.
Dark red to purple bands of Tava sandstone dissect pink and white granite. The Tava is also cross-cut by silvery-gray veins of iron oxide. Liam Courtney-Davies

An obstacle for testing this idea, however, has been the lack of an age for the rocks to reveal when the right geological circumstances existed for sand injection.

We found a way to solve that mystery, using veins of iron found alongside the Tava injectites, near Pikes Peak and elsewhere in Colorado.

A cliff side showing a long strip of lighter color Tava cutting through Pikes Peak Granite. The injectite here is 5 meters tall
A 5-meter-tall, almost vertical Tava dike is evident in this section of Pikes Peak granite. Liam Courtney-Davies

Iron minerals contain very low amounts of naturally occurring radioactive elements, including uranium, which slowly decays to the element lead at a known rate. Recent advancements in laser-based radiometric dating allowed us to measure the ratio of uranium to lead isotopes in the iron oxide mineral hematite to reveal how long ago the individual crystals formed.

The iron veins appear to have formed both before and after the sand was injected into the Colorado bedrock: We found veins of hematite and quartz that both cut through Tava dikes and were crosscut by Tava dikes. That allowed us to figure out an age bracket for the sand injectites, which must have formed between 690 million and 660 million years ago.

So, what happened?

The time frame means these sandstones formed during the Cryogenian Period, from 720 million to 635 million years ago. The name is derived from “cold birth” in ancient Greek and is synonymous with climate upheaval and disruption of life on our planet – including Snowball Earth.

While the triggers for the extreme cold at that time are debated, prevailing theories involve changes in tectonic plate activity, including the release of particles into the atmosphere that reflected sunlight away from Earth. Eventually, a buildup of carbon dioxide from volcanic outgassing may have warmed the planet again.

University of Exeter professor Timothy Lenton explains why the Earth was able to freeze over.

The Tava found on Pikes Peak would have formed close to the equator within the heart of an ancient continent named Laurentia, which gradually over time and long tectonic cycles moved into its current northerly position in North America today.

The origin of Tava rocks has been debated for over 125 years, but the new technology allowed us to conclusively link them to the Cryogenian Snowball Earth period for the first time.

The scenario we envision for how the sand injection happened looks something like this:

A giant ice sheet with areas of geothermal heating at its base produced meltwater, which mixed with quartz-rich sediment below. The weight of the ice sheet created immense pressures that forced this sandy fluid into bedrock that had already been weakened over millions of years. Similar to fracking for natural gas or oil today, the pressure cracked the rocks and pushed the sandy meltwater in, eventually creating the injectites we see today.

Clues to another geologic puzzle

Not only do the new findings further cement the global Snowball Earth hypothesis, but the presence of Tava injectites within weak, fractured rocks once overridden by ice sheets provides clues about other geologic phenomena.

Time gaps in the rock record created through erosion and referred to as unconformities can be seen today across the United States, most famously at the Grand Canyon, where in places, over a billion years of time is missing. Unconformities occur when a sustained period of erosion removes and prevents newer layers of rock from forming, leaving an unconformable contact.

Unconformity in the Grand Canyon is evident here where horizontal layers of 500-million-year-old rock sit on top of a mass of 1,800-million-year-old rocks. The unconformity, or ‘time gap,’ demonstrates that years of history are missing. Mike Norton via Wikimedia, CC BY-SA

Our results support that a Great Unconformity near Pikes Peak must have been formed prior to Cryogenian Snowball Earth. That’s at odds with hypotheses that attribute the formation of the Great Unconformity to large-scale erosion by Snowball Earth ice sheets themselves.

We hope the secrets of these elusive Cryogenian rocks in Colorado will lead to the discovery of further terrestrial records of Snowball Earth. Such findings can help develop a clearer picture of our planet during climate extremes and the processes that led to the habitable planet we live on today.

Liam Courtney-Davies, Postdoctoral Research Associate in Geological Sciences, University of Colorado Boulder; Christine Siddoway, Professor of Geology, Colorado College, and Rebecca Flowers, Professor of Geological Sciences, University of Colorado Boulder

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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All I can add is fascinating.

The summer of 2024 in the Northern Hemisphere.

Once more, an article on the changing climate.

Recently, the BBC News reported that:

Global efforts to tackle climate change are wildly off track, says the UN, as new data shows that warming gases are accumulating faster than at any time in human existence.

Current national plans to limit carbon emissions would barely cut pollution by 2030, the UN analysis shows, leaving efforts to keep warming under 1.5C this century in tatters.

The update comes as a separate report shows that greenhouse gases have risen by over 11% in the last two decades, with atmospheric concentrations surging in 2023.

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What the jet stream and climate change had to do with the hottest summer on record − remember all those heat domes?

Shuang-Ye Wu, University of Dayton

Summer 2024 was officially the Northern Hemisphere’s hottest on record. In the United States, fierce heat waves seemed to hit somewhere almost every day.

Phoenix reached 100 degrees for more than 100 days straight. The 2024 Olympic Games started in the midst of a long-running heat wave in Europe that included the three hottest days on record globally, July 21-23. August was Earth’s hottest month in the National Oceanic and Atmospheric Administration’s 175-year record.

Overall, the global average temperature was 2.74 degrees Fahrenheit (1.52 degrees Celsius) above the 20th-century average.

That might seem small, but temperature increases associated with human-induced climate change do not manifest as small, even increases everywhere on the planet. Rather, they result in more frequent and severe episodes of heat waves, as the world saw in 2024.

The most severe and persistent heat waves are often associated with an atmospheric pattern called a heat dome. As an atmospheric scientist, I study weather patterns and the changing climate. Here’s how heat domes, the jet stream and climate change influence summer heat waves and the record-hot summer of 2024.

What the jet stream has to do with heat domes

If you listened to weather forecasts during the summer of 2024, you probably heard the term “heat dome” a lot.

A heat dome is a persistent high-pressure system over a large area. A high-pressure system is created by sinking air. As air sinks, it warms up, decreasing relative humidity and leaving sunny weather. The high pressure also serves as a lid that keeps hot air on the surface from rising and dissipating. The resulting heat dome can persist for days or even weeks.

The longer a heat dome lingers, the more heat will build up, creating sweltering conditions for the people on the ground.

A 3D image of the US showing a heat dome above it.
High pressure in the middle layers of the atmosphere acts as a dome or cap, allowing heat to build up at the Earth’s surface. NOAA

How long these heat domes stick around has a lot to do with the jet stream.

The jet stream is a narrow band of strong winds in the upper atmosphere, about 30,000 feet above sea level. It moves from west to east due to the Earth’s rotation. The strong winds are a result of the sharp temperature difference where the warm tropical air meets the cold polar air from the north in the mid-latitudes.

The jet stream does not flow along a straight path. Rather, it meanders to the north and south in a wavy pattern. These giant meanders are known as the Rossby waves, and they have a major influence on weather.

An illustration shows how ridges create high pressure to the south of them and troughs create low pressure to the north of them.
Ridges and troughs created as the jet stream meanders through the mid-latitudes create high (H) and low (L) pressure systems. Reds indicate the fastest winds. NASA/Goddard Space Flight Center Scientific Visualization Studio

Where the jet stream arcs northward, forming a ridge, it creates a high-pressure system south of the wave. Where the jet stream dips southward, forming a trough, it creates a low-pressure system north of the jet stream. A low-pressure system contains rising air in the center, which cools and tends to generate precipitation and storms.

Most of our weather is modulated by the position and characteristics of the jet stream.

How climate change affects the jet stream

The jet stream, or any wind, is the result of differences in surface temperature.

In simple terms, warm air rises, creating low pressure, and cold air sinks, creating high pressure. Wind is the movement of the air from high to low pressure. Greater differences in temperature produce stronger winds.

For the Earth as a whole, warm air rises near the equator, and cold air sinks near the poles. The temperature difference between the equator and the pole determines the strength of the jet stream in each hemisphere.

However, that temperature difference has been changing, particularly in the Northern Hemisphere. The Arctic region has been warming about three times faster than the global average. This phenomenon, known as Arctic amplification, is largely caused by the melting of Arctic sea ice, which allows the exposed dark water to absorb more of the Sun’s radiation and heat up faster.

Because the Arctic is warming faster than the tropics, the temperature difference between the two regions is lessened. And that slows the jet stream.

As the jet stream slows, it tends to meander more, causing bigger waves. The bigger waves create larger high-pressure systems. These can often be blocked by the deep low-pressure systems on both sides, causing the high-pressure system to sit over a large area for a long period of time.

A stagnant polar jet stream can trapped heat over parts of North America, Europe and Asia at the same time. This example happened in July 2023. UK Met Office

Typically, waves in the jet stream pass through the continental United States in around three to five days. When blocking occurs, however, the high-pressure system could stagnate for days to weeks. This allows the heat to build up underneath, leading to blistering heat waves.

Since the jet stream circles around the globe, stagnating waves could occur in multiple places, leading to simultaneous heat waves at the mid-latitude around the world. That happened in 2024, with long-lasting heat waves in Europe, North America, Central Asia and China.

Jet stream behavior affects winter, too

The same meandering behavior of the jet stream also plays a role in extreme winter weather. That includes the southward intrusion of frigid polar air from the polar vortex and conditions for severe winter storms.

Many of these atmospheric changes, driven by human-caused global warming, have significant impacts on people’s health, property and ecosystems around the world.

Shuang-Ye Wu, Professor of Geology and Environmental Geosciences, University of Dayton

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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I maybe approaching my own end of life but millions of others are younger than me. When I see a woman with a young baby in her arms I cannot stop myself from wondering what that generation is going to do.

The changing climate

Here is one explanation.

There is no question the world’s weather systems are changing. However, for folk who are not trained in this science it is all a bit mysterious. So thank goodness that The Conversation have not only got a scientist who does know what he is talking about but also they are very happy for it to be republished.

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Atmospheric rivers are shifting poleward, reshaping global weather patterns

Atmospheric rivers are long filaments of moisture that curve poleward. Several are visible in this satellite image. Bin Guan, NASA/JPL-Caltech and UCLA

Zhe Li, University Corporation for Atmospheric Research

Atmospheric rivers – those long, narrow bands of water vapor in the sky that bring heavy rain and storms to the U.S. West Coast and many other regions – are shifting toward higher latitudes, and that’s changing weather patterns around the world.

The shift is worsening droughts in some regions, intensifying flooding in others, and putting water resources that many communities rely on at risk. When atmospheric rivers reach far northward into the Arctic, they can also melt sea ice, affecting the global climate.

In a new study published in Science Advances, University of California, Santa Barbara, climate scientist Qinghua Ding and I show that atmospheric rivers have shifted about 6 to 10 degrees toward the two poles over the past four decades.

Atmospheric rivers on the move

Atmospheric rivers aren’t just a U.S West Coast thing. They form in many parts of the world and provide over half of the mean annual runoff in these regions, including the U.S. Southeast coasts and West Coast, Southeast Asia, New Zealand, northern Spain, Portugal, the United Kingdom and south-central Chile.

California relies on atmospheric rivers for up to 50% of its yearly rainfall. A series of winter atmospheric rivers there can bring enough rain and snow to end a drought, as parts of the region saw in 2023.

Atmospheric rivers occur all over the world, as this animation of global satellite data from February 2017 shows. NASA/Goddard Space Flight Center Scientific Visualization Studio

While atmospheric rivers share a similar origin – moisture supply from the tropics – atmospheric instability of the jet stream allows them to curve poleward in different ways. No two atmospheric rivers are exactly alike.

What particularly interests climate scientists, including us, is the collective behavior of atmospheric rivers. Atmospheric rivers are commonly seen in the extratropics, a region between the latitudes of 30 and 50 degrees in both hemispheres that includes most of the continental U.S., southern Australia and Chile.

Our study shows that atmospheric rivers have been shifting poleward over the past four decades. In both hemispheres, activity has increased along 50 degrees north and 50 degrees south, while it has decreased along 30 degrees north and 30 degrees south since 1979. In North America, that means more atmospheric rivers drenching British Columbia and Alaska.

A global chain reaction

One main reason for this shift is changes in sea surface temperatures in the eastern tropical Pacific. Since 2000, waters in the eastern tropical Pacific have had a cooling tendency, which affects atmospheric circulation worldwide. This cooling, often associated with La Niña conditions, pushes atmospheric rivers toward the poles.

The poleward movement of atmospheric rivers can be explained as a chain of interconnected processes.

During La Niña conditions, when sea surface temperatures cool in the eastern tropical Pacific, the Walker circulation – giant loops of air that affect precipitation as they rise and fall over different parts of the tropics – strengthens over the western Pacific. This stronger circulation causes the tropical rainfall belt to expand. The expanded tropical rainfall, combined with changes in atmospheric eddy patterns, results in high-pressure anomalies and wind patterns that steer atmospheric rivers farther poleward.

An animation of satellite data shows sea surface temperatures changing over months along the equator in the eastern Pacific Ocean. When they're warmer than normal, that indicates El Niño forming. Cooler than normal indicates La Nina.
La Niña, with cooler water in the eastern Pacific, fades, and El Niño, with warmer water, starts to form in the tropical Pacific Ocean in 2023. NOAA Climate.gov

Conversely, during El Niño conditions, with warmer sea surface temperatures, the mechanism operates in the opposite direction, shifting atmospheric rivers so they don’t travel as far from the equator.

The shifts raise important questions about how climate models predict future changes in atmospheric rivers. Current models might underestimate natural variability, such as changes in the tropical Pacific, which can significantly affect atmospheric rivers. Understanding this connection can help forecasters make better predictions about future rainfall patterns and water availability.

Why does this poleward shift matter?

A shift in atmospheric rivers can have big effects on local climates.

In the subtropics, where atmospheric rivers are becoming less common, the result could be longer droughts and less water. Many areas, such as California and southern Brazil, depend on atmospheric rivers for rainfall to fill reservoirs and support farming. Without this moisture, these areas could face more water shortages, putting stress on communities, farms and ecosystems.

In higher latitudes, atmospheric rivers moving poleward could lead to more extreme rainfall, flooding and landslides in places such as the U.S. Pacific Northwest, Europe, and even in polar regions.

A long narrow band of moisture sweeps up toward California, crossing hundreds of miles of Pacific Ocean.
A satellite image on Feb. 20, 2017, shows an atmospheric river stretching from Hawaii to California, where it brought drenching rain. NASA/Earth Observatory/Jesse Allen

In the Arctic, more atmospheric rivers could speed up sea ice melting, adding to global warming and affecting animals that rely on the ice. An earlier study I was involved in found that the trend in summertime atmospheric river activity may contribute 36% of the increasing trend in summer moisture over the entire Arctic since 1979.

What it means for the future

So far, the shifts we have seen still mainly reflect changes due to natural processes, but human-induced global warming also plays a role. Global warming is expected to increase the overall frequency and intensity of atmospheric rivers because a warmer atmosphere can hold more moisture.

How that might change as the planet continues to warm is less clear. Predicting future changes remains uncertain due largely to the difficulty in predicting the natural swings between El Niño and La Niña, which play an important role in atmospheric river shifts.

As the world gets warmer, atmospheric rivers – and the critical rains they bring – will keep changing course. We need to understand and adapt to these changes so communities can keep thriving in a changing climate.

Zhe Li, Postdoctoral Researcher in Earth System Science, University Corporation for Atmospheric Research

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Those last two paragraphs of the above article show the difficulty in coming up with clear predictions of the future. As was said: ‘How that might change as the planet continues to warm is less clear. Predicting future changes remains uncertain due largely to the difficulty in predicting the natural swings between El Niño and La Niña, which play an important role in atmospheric river shifts.‘

Ancient times

This attracted me very much, and I wanted to share it with you.

The opening paragraph of this article caught my eye so I read it fully. As it was published in The Conversation then that meant I could republish it.

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Centuries ago, the Maya storm god Huracán taught that when we damage nature, we damage ourselves

An illustration of K’awiil, the Maya god of storm, on pottery. K2970 from the Justin Kerr Maya archive, Dumbarton Oaks, Trustees for Harvard University, Washington, D.C.

James L. Fitzsimmons, Middlebury

The ancient Maya believed that everything in the universe, from the natural world to everyday experiences, was part of a single, powerful spiritual force. They were not polytheists who worshipped distinct gods but pantheists who believed that various gods were just manifestations of that force.

Some of the best evidence for this comes from the behavior of two of the most powerful beings of the Maya world: The first is a creator god whose name is still spoken by millions of people every fall – Huracán, or “Hurricane.” The second is a god of lightning, K’awiil, from the early first millennium C.E.

As a scholar of the Indigenous religions of the Americas, I recognize that these beings, though separated by over 1,000 years, are related and can teach us something about our relationship to the natural world.

Huracán, the ‘Heart of Sky’

Huracán was once a god of the K’iche’, one of the Maya peoples who today live in the southern highlands of Guatemala. He was one of the main characters of the Popol Vuh, a religious text from the 16th century. His name probably originated in the Caribbean, where other cultures used it to describe the destructive power of storms.

The K’iche’ associated Huracán, which means “one leg” in the K’iche’ language, with weather. He was also their primary god of creation and was responsible for all life on earth, including humans.

Because of this, he was sometimes known as U K’ux K’aj, or “Heart of Sky.” In the K’iche’ language, k’ux was not only the heart but also the spark of life, the source of all thought and imagination.

Yet, Huracán was not perfect. He made mistakes and occasionally destroyed his creations. He was also a jealous god who damaged humans so they would not be his equal. In one such episode, he is believed to have clouded their vision, thus preventing them from being able to see the universe as he saw it.

Huracán was one being who existed as three distinct persons: Thunderbolt Huracán, Youngest Thunderbolt and Sudden Thunderbolt. Each of them embodied different types of lightning, ranging from enormous bolts to small or sudden flashes of light.

Despite the fact that he was a god of lightning, there were no strict boundaries between his powers and the powers of other gods. Any of them might wield lightning, or create humanity, or destroy the Earth.

Another storm god

The Popol Vuh implies that gods could mix and match their powers at will, but other religious texts are more explicit. One thousand years before the Popol Vuh was written, there was a different version of Huracán called K’awiil. During the first millennium, people from southern Mexico to western Honduras venerated him as a god of agriculture, lightning and royalty.

A drawing showing a reclining god-like figure with a large snake around him.
The ancient Maya god K’awiil, left, had an ax or torch in his forehead as well as a snake in place of his right leg. K5164 from the Justin Kerr Maya archive, Dumbarton Oaks, Trustees for Harvard University, Washington, D.C.

Illustrations of K’awiil can be found everywhere on Maya pottery and sculpture. He is almost human in many depictions: He has two arms, two legs and a head. But his forehead is the spark of life – and so it usually has something that produces sparks sticking out of it, such as a flint ax or a flaming torch. And one of his legs does not end in a foot. In its place is a snake with an open mouth, from which another being often emerges.

Indeed, rulers, and even gods, once performed ceremonies to K’awiil in order to try and summon other supernatural beings. As personified lightning, he was believed to create portals to other worlds, through which ancestors and gods might travel.

Representation of power

For the ancient Maya, lightning was raw power. It was basic to all creation and destruction. Because of this, the ancient Maya carved and painted many images of K’awiil. Scribes wrote about him as a kind of energy – as a god with “many faces,” or even as part of a triad similar to Huracán.

He was everywhere in ancient Maya art. But he was also never the focus. As raw power, he was used by others to achieve their ends.

Rain gods, for example, wielded him like an ax, creating sparks in seeds for agriculture. Conjurers summoned him, but mostly because they believed he could help them communicate with other creatures from other worlds. Rulers even carried scepters fashioned in his image during dances and processions.

Moreover, Maya artists always had K’awiil doing something or being used to make something happen. They believed that power was something you did, not something you had. Like a bolt of lightning, power was always shifting, always in motion.

An interdependent world

Because of this, the ancient Maya thought that reality was not static but ever-changing. There were no strict boundaries between space and time, the forces of nature or the animate and inanimate worlds.

People walking through knee-deep water on a flooded street with building on either side and electric wires overhead.
Residents wade through a street flooded by Hurricane Helene, in Batabano, Mayabeque province, Cuba, on Sept. 26, 2024. AP Photo/Ramon Espinosa

Everything was malleable and interdependent. Theoretically, anything could become anything else – and everything was potentially a living being. Rulers could ritually turn themselves into gods. Sculptures could be hacked to death. Even natural features such as mountains were believed to be alive.

These ideas – common in pantheist societies – persist today in some communities in the Americas.

They were once mainstream, however, and were a part of K’iche’ religion 1,000 years later, in the time of Huracán. One of the lessons of the Popol Vuh, told during the episode where Huracán clouds human vision, is that the human perception of reality is an illusion.

The illusion is not that different things exist. Rather it is that they exist independent from one another. Huracán, in this sense, damaged himself by damaging his creations.

Hurricane season every year should remind us that human beings are not independent from nature but part of it. And like Hurácan, when we damage nature, we damage ourselves.

James L. Fitzsimmons, Professor of Anthropology, Middlebury

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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It is such a powerful message, that when we damage nature, we damage ourselves.

But I am unaware, no we are both unaware of a solution, and there doesn’t appear to be a government desire to make this the number one topic.

Please, if there is anyone who reads this post and has a more positive message then we would be very keen to hear from you.

The Heart Wall in London

I love this!

I am writing this having listened to a programme on BBC Radio 4. (Was broadcast on Radio 4 on Tuesday, August 13th.) It shows how many, many people can have a really positive response to a dastardly negative occurrence such as the Covid outbreak or a pandemic.

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Photo by Nick Fewings on Unsplash

Why are those lost to COVID not formally memorialised? How politics shapes what we remember

Mark Honigsbaum, City, University of London

Every Friday, volunteers gather on the Albert Embankment at the River Thames in London to lovingly retouch thousands of red hearts inscribed on a Portland stone wall directly opposite the Houses of Parliament. Each heart is dedicated to a British victim of COVID. It is a deeply social space – a place where the COVID bereaved come together to honour their dead and share memories.

The so-called National Covid Memorial Wall is not, however, officially sanctioned. In fact, ever since activists from COVID-19 Bereaved Families for Justice (CBFFJ) daubed the first hearts on the wall in March 2021 it has been a thorn in the side of the authorities.

Featured in the media whenever there is a new revelation about partygate, the wall is a symbol of the government’s blundering response to the pandemic and an implicit rebuke to former prime minister Boris Johnson and other government staff who breached coronavirus restrictions.

As one writer put it, viewed from parliament the hearts resemble “a reproachful smear of blood”. Little wonder that the only time Johnson visited the wall was under the cover of darkness to avoid the TV cameras. His successor Rishi Sunak has been similarly reluctant to acknowledge the wall or say what might take its place as a more formal memorial to those lost in the pandemic.

Though in April the UK Commission on COVID Commemoration presented Sunak with a report on how the pandemic should be remembered, Sunak has yet to reveal the commission’s recommendations.

Lady Heather Hallett, the former high court judge who chairs the public inquiry into COVID, has attempted to acknowledge the trauma of the bereaved by commissioning a tapestry to capture the experiences of people who “suffered hardship and loss” during the pandemic. Yet such initiatives are no substitute for state-sponsored memorials.

What is remembered and what is forgotten?

This political vacuum is odd when you consider that the United Kingdom, like other countries, engages in many other commemorative activities central to national identity. The fallen of the first world war and other military conflicts are commemorated in a Remembrance Sunday ceremony held every November at the Cenotaph in London, for example.

But while wars lend themselves to compelling moral narratives, it is difficult to locate meaning in the random mutations of a virus. And while wars draw on a familiar repertoire of symbols and rituals, pandemics have few templates.

For instance, despite killing more than 50 million globally, there are virtually no memorials to the 1918-1919 “Spanish” influenza pandemic. Nor does the UK have a memorial to victims of HIV/AIDS. As the memory studies scholar Astrid Erll puts it, pandemics have not been sufficiently “mediated” in collective memory.

As a rule, they do not feature in famous paintings, novels or films or in the oral histories passed down as part of family lore. Nor are they able to draw on familiar cultural materials such as poppies, gun carriages, catafalques and royal salutes. Without such symbols and schemata, Erll argues, we struggle to incorporate pandemics into our collective remembering systems.

This lacuna was brought home to me last September when tens of thousands of Britons flocked to the south bank of the Thames to pay their respects to Britain’s longest serving monarch. By coincidence, the police directed the queue for the late Queen’s lying-in-state in Westminster Hall over Lambeth Bridge and along Albert Embankment.

But few of the people I spoke to in the queue seemed to realise what the hearts signified. It was as if the spectacle of a royal death had eclipsed the suffering of the COVID bereaved, rendering the wall all but invisible.

Waiting for answers

Another place where the pandemic could be embedded in collective memory is at the public inquiry. Opening the preliminary hearing last October into the UK’s resilience and preparedness for a pandemic, Lady Hallett promised to put the estimated 6.8 million Britons mourning the death of a family member or friend to COVID at the heart of the legal process. “I am listening to them; their loss will be recognised,” she said.

But though Lady Hallett has strategically placed photographs of the hearts throughout the inquiry’s offices in Bayswater and has invited the bereaved to relate their experiences to “Every Story Matters”, the hearing room is dominated by ranks of lawyers. And except when a prominent minister or official is called to testify, the proceedings rarely make the news.

This is partly the fault of the inquiry process itself. The hearings are due to last until 2025, with the report on the first stage of the process not expected until the summer of 2024. As Lucy Easthope, an emergency planner and veteran of several disasters, puts it: “one of the most painful frustrations of the inquiry will be temporal. It will simply take too long.”

The inquiry has also been beset by bureaucratic obfuscation, not least by the Cabinet Office which attempted (unsuccessfully in the end) to block the release of WhatsApp messages relating to discussions between ministers and Downing Street officials in the run-up to lockdown.

To the inquiry’s critics, the obvious parallel is with the Grenfell inquiry, which promised to “learn lessons” from the devastating fire that engulfed the west London tower in 2017 but has so far ended up blurring the lines of corporate responsibility and forestalling a political reckoning.

The real work of holding the government to account and making memories takes place every Friday at the wall and the other places where people come together to spontaneously mourn and remember absent loved ones. These are the lives that demand to be “seen”. They are the ghosts that haunt our amnesic political culture.

Mark Honigsbaum, Senior Lecturer in Journalism, City, University of London

This article is republished from The Conversation under a Creative Commons license. Read the original article.

plus Wikipedia have a long article on the National Covid Memorial Wall. That then takes us to the website for the wall.

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As was written in the last sentence of the article; ‘They are the ghosts that haunt our amnesic political culture.‘

Humans are a strange lot and I most certainly count myself in!

Essentially, life is about play

We take our decision from watching the animal kingdom.

A recent post in The Conversation provides the article for today’s blog post.

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At its core, life is all about play − just look at the animal kingdom

Throw it to me! Mike Linnane / 500px via Getty Images

David Toomey, UMass Amherst

At Cambridge University Library, along with all the books, maps and manuscripts, there’s a child’s drawing that curators have titled “The Battle of the Fruit and Vegetable Soldiers.”

The drawing depicts a turbaned cavalry soldier facing off against an English dragoon. It’s a bit trippy: The British soldier sits astride a carrot, and the turbaned soldier rides a grape. Both carrot and grape are fitted with horses’ heads and stick appendages.

A child's drawing of two soldiers ridind a grape and a carrot
‘The Battle of the Fruit and Vegetable Soldiers,’ a drawing on the back of a manuscript page from Charles Darwin’s ‘On the Origin of Species,’ attributed to Darwin’s young son Francis. Cambridge University Library, CC BY-ND

It’s thought to be the work of Francis Darwin, the seventh child of British naturalist Charles Darwin and his wife, Emma, and appears to have been made in 1857, when Frank would have been 10 or 11. And it’s drawn on the back of a page of a draft of “On the Origin of Species,” Darwin’s masterwork and the foundational text of evolutionary biology. The few sheets of the draft that survive are pages Darwin gave to his children to use for drawing paper.

Darwin’s biographers have long recognized that play was important in his personal and familial life. The Georgian manor in which he and Emma raised their 10 children was furnished with a rope swing hung over the first-floor landing and a portable wooden slide that could be laid over the main stairway. The gardens and surrounding countryside served as an open-air laboratory and playground.

Play also has a role in Darwin’s theory of natural selection. As I explain in my new book, “Kingdom of Play: What Ball-bouncing Octopuses, Belly-flopping Monkeys, and Mud-sliding Elephants Reveal about Life Itself,” there are many similarities – so many that if you could distill the processes of natural selection into a single behavior, that behavior would be play.

No goal, no direction

Natural selection is the process by which organisms that are best adapted to their environments are more likely to survive, and so able to pass on the characteristics that helped them thrive to their offspring. It is undirected: In Darwin’s words, it “includes no necessary and universal law of advancement or development.”

Through natural selection, the rock pocket mouse has evolved a coat color that hides it from predators in the desert Southwest.

In contrast to foraging and hunting – behaviors with clearly defined goals – play is likewise undirected. When a pony frolics in a field, a dog wrestles with a stick or chimpanzees chase each other, they act with no goal in mind.

Natural selection is utterly provisional: The evolution of any organism responds to whatever conditions are present at a given place and time. Likewise, animals at play are acting provisionally. They constantly adjust their movements in response to changes in circumstances. Playing squirrels, faced with obstacles such as falling branches or other squirrels, nimbly alter their tactics and routes.

Natural selection is open-ended. The forms of life are not fixed, but continually evolving. Play, too, is open-ended. Animals begin a play session with no plan of when to end it. Two dogs play-fighting, for instance, cease playing only when one is injured, exhausted or simply loses interest.

Natural selection also is wasteful, as Darwin acknowledged. “Many more individuals of each species are born than can possibly survive,” he wrote. But in the long term, he allowed, such profligacy could produce adaptations that enable an evolutionary line to become “more fit.”

Keepers noticed that Shanthi, a 36-year-old elephant at the Smithsonian national zoo, liked to make noise with objects, so they gave her horns, harmonicas and other noisemakers.

Play is likewise profligate. It requires an animal to expend time and energy that perhaps would be better devoted to behaviors such as foraging and hunting that could aid survival.

And that profligacy is also advantageous. Animals forage and hunt in specific ways that don’t typically change. But an animal at play is far more likely to innovate – and some of its innovations may in time be adapted into new ways to forage and hunt.

Competing and cooperating

As Darwin first framed it, the “struggle for existence” was by and large a competition. But in the 1860s, Russian naturalist Pyotr Kropotkin’s observations of birds and fallow deer led him to conclude that many species were “the most numerous and the most prosperous” because natural selection also selects for cooperation.

Scientists confirmed Kroptokin’s hypothesis in the 20th century, discovering all manner of cooperation, not only between members of the same species but between members of different species. For example, clown fish are immune to anemone stings; they nestle in anemone tentacles for protection and, in return, keep the anemones free of parasites, provide nutrients and drive away predators.

Play likewise utilizes both competition and cooperation. Two dogs play-fighting are certainly competing, yet to sustain their play, they must cooperate. They often reverse roles: A dog with the advantage of position might suddenly surrender that advantage and roll over on its back. If one bites harder than intended, it is likely to retreat and perform a play bow – saying, in effect, “My bad. I hope we can keep playing.”

River otters at the Oregon Zoo repeatedly separate and reunite while playing in a tub of ice.

Natural selection and play also may both employ deception. From butterflies colored to resemble toxic species to wild cats that squeal like distressed baby monkeys, many organisms use mimicry to deceive their prey, predators and rivals. Play – specifically, play-fighting – similarly offers animals opportunities to learn about and practice deception.

To live is to play

Darwin wrote that natural selection creates “endless forms most beautiful and most wonderful.” Play also creates beauty in countless ways, from the aerial acrobatics of birds of prey to the arcing, twisting leaps of dolphins.

In 1973, Ukrainian-American geneticist Theodosius Dobzhansky published an essay with the take-no-prisoners title “Nothing in Biology Makes Sense Except in the Light of Evolution.” Many biologists would agree. Perhaps the most satisfying definition of life attends not to what it is but to what it does – which is to say, life is what evolves by natural selection.

And since natural selection shares so many features with play, we may with some justification maintain that life, in a most fundamental sense, is playful.

David Toomey, Professor of English, UMass Amherst

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Prof. Toomey’s analysis is spot-on.

All of life involves some form of play.

Our amazing trees.

Beyond our imagination.

Until quite recently I had imagined that a tree was just a tree. Then Jean and I got to watch a YouTube video on trees and it blew our minds. Here is what we watched:

That led us on to watching Judi Dench’s video of trees:

Which is a longish introduction to a piece on The Conversation about trees.

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Trees don’t like to breathe wildfire smoke, either – and they’ll hold their breath to avoid it

Trees and other plants can’t escape wildfire smoke. Patrick T. Fallon/AFP via Getty Images

Delphine Farmer, Colorado State University and Mj Riches, Colorado State University

When wildfire smoke is in the air, doctors urge people to stay indoors to avoid breathing in harmful particles and gases. But what happens to trees and other plants that can’t escape from the smoke?

They respond a bit like us, it turns out: Some trees essentially shut their windows and doors and hold their breath.

As atmospheric and chemical scientists, we study the air quality and ecological effects of wildfire smoke and other pollutants. In a study that started quite by accident when smoke overwhelmed our research site in Colorado, we were able to watch in real time how the leaves of living pine trees responded.

How plants breathe

Plants have pores on the surface of their leaves called stomata. These pores are much like our mouths, except that while we inhale oxygen and exhale carbon dioxide, plants inhale carbon dioxide and exhale oxygen.

A highly magnified view of stomata in a maize leaf. Umberto Salvagnin/Flickr, CC BY

Both humans and plants inhale other chemicals in the air around them and exhale chemicals produced inside them – coffee breath for some people, pine scents for some trees.

Unlike humans, however, leaves breathe in and out at the same time, constantly taking in and releasing atmospheric gases.

Clues from over a century of research

In the early 1900s, scientists studying trees in heavily polluted areas discovered that those chronically exposed to pollution from coal-burning had black granules clogging the leaf pores through which plants breathe. They suspected that the substance in these granules was partly created by the trees, but due to the lack of available instruments at the time, the chemistry of those granules was never explored, nor were the effects on the plants’ photosynthesis.

Most modern research into wildfire smoke’s effects has focused on crops, and the results have been conflicting.

For example, a study of multiple crop and wetland sites in California showed that smoke scatters light in a way that made plants more efficient at photosynthesis and growth. However, a lab study in which plants were exposed to artificial smoke found that plant productivity dropped during and after smoke exposure – though those plants did recover after a few hours.

There are other clues that wildfire smoke can impact plants in negative ways. You may have even tasted one: When grapes are exposed to smoke, their wine can be tainted.

What makes smoke toxic, even far from the fire

When wildfire smoke travels long distances, the smoke cooks in sunlight and chemically changes.

Mixing volatile organic compounds, nitrogen oxides and sunlight will make ground-level ozone, which can cause breathing problems in humans. It can also damage plants by degrading the leaf surface, oxidizing plant tissue and slowing photosynthesis.

Illustration of a burning tree with particles showing their size.
Smoke has particles much smaller than the width of a hair and gases that evolve in sunlight. Jen Burgess/IsolineStudios for BC Centre for Disease Control

While scientists usually think about urban regions as being large sources of ozone that effect crops downwind, wildfire smoke is an emerging concern. Other compounds, including nitrogen oxides, can also harm plants and reduce photosynthesis.

Taken together, studies suggest that wildfire smoke interacts with plants, but in poorly understood ways. This lack of research is driven by the fact that studying smoke effects on the leaves of living plants in the wild is hard: Wildfires are hard to predict, and it can be unsafe to be in smoky conditions.

Accidental research – in the middle of a wildfire

We didn’t set out to study plant responses to wildfire smoke. Instead, we were trying to understand how plants emit volatile organic compounds – the chemicals that make forests smell like a forest, but also impact air quality and can even change clouds.

Fall 2020 was a bad season for wildfires in the western U.S., and thick smoke came through a field site where we were working in the Rocky Mountains of Colorado.

On the first morning of heavy smoke, we did our usual test to measure leaf-level photosynthesis of Ponderosa pines. We were surprised to discover that the tree’s pores were completely closed and photosynthesis was nearly zero.

We also measured the leaves’ emissions of their usual volatile organic compounds and found very low readings. This meant that the leaves weren’t “breathing” – they weren’t inhaling the carbon dioxide they need to grow and weren’t exhaling the chemicals they usually release.

Side-by-side photos show the air was smoky, similar to a foggy or smoggy day, but no so think that you can't see the forest ahead.
A clear day at the Colorado test site, on the left, compared to the smoky day when trees responded to the poor air quality, on the right. Mj Riches, CC BY-SA

With these unexpected results, we decided to try to force photosynthesis and see if we could “defibrillate” the leaf into its normal rhythm. By changing the leaf’s temperature and humidity, we cleared the leaf’s “airways” and saw a sudden improvement in photosynthesis and a burst of volatile organic compounds.

What our months of data told us is that some plants respond to heavy bouts of wildfire smoke by shutting down their exchange with outside air. They are effectively holding their breath, but not before they have been exposed to the smoke.

We hypothesize a few processes that could have caused leaves to close their pores: Smoke particles could coat the leaves, creating a layer that prevents the pores from opening. Smoke could also enter the leaves and clog their pores, keeping them sticky. Or the leaves could physically respond to the first signs of smoke and close their pores before they get the worst of it.

It’s likely a combination of these and other responses.

The long-term impact is still unknown

The jury is still out on exactly how long the effects of wildfire smoke last and how repeated smoke events will affect plants – including trees and crops – over the long term.

With wildfires increasing in severity and frequency due to climate change, forest management policies and human behavior, it’s important to gain a better understanding of the impact.

Delphine Farmer, Professor of Chemistry, Colorado State University and Mj Riches, Postdoctoral Researcher in Environmental and Atmospheric Science, Colorado State University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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The biggest tree in the world is reputed to be the General Sherman tree in California. Here is the introduction from WikiPedia:

General Sherman is a giant sequoia (Sequoiadendron giganteum) tree located at an elevation of 2,109 m (6,919 ft) above sea level in the Giant Forest of Sequoia National Park in Tulare County, in the U.S. state of California. By volume, it is the largest known living single-stem tree on Earth.

Amazing!