#National University of Mexico

[blueiscoool]

Earthquake Reveals Aztec Snakehead Beneath Mexico City

Researchers are conserving a rare snakehead from the Aztecs that still retains its painted colors from hundreds of years ago.

An earthquake last year revealed a big surprise beneath a law school in modern-day Mexico City: a giant, colorful snakehead from the Aztec Empire.

The snakehead dates back more than 500 years, to when the Aztecs controlled the area, which at the time was part of the flourishing capital of Tenochtitlan. The sculpture was discovered after a magnitude-7.6 earthquake struck Mexico City on Sept. 19, 2022; the seismic event caused damage and changes in the topography, revealing the snakehead beneath a building that was part of a law school at the National Autonomous University of Mexico, Mexico's National Institute of Anthropology and History (INAH) said in a Spanish-language statement.

The Aztecs built temples and pyramids and worshipped a number of deities, including Quetzalcoatl, who was often depicted as a snake. However, it's unclear if this sculpture depicts him, the archaeologists said.

The sculpted snake is 5.9 feet (1.8 meters) long, 2.8 feet (0.85 m) wide and 3.3 feet (1 m) high, and it weighs about 1.3 tons (1.2 metric tons), the INAH said. Several colors — including red, blue, black and white — are preserved on the sculpture.

Color was preserved on about 80% of the sculpture's surface. To keep it preserved, an INAH team lifted the snakehead out of the ground with a crane and constructed a humidity chamber around the sculpture. This chamber allows the sculpture to lose humidity gradually, with its color being preserved, María Barajas Rocha, a conservationist with the INAH who worked extensively on the sculpture, said in the statement.

While other snakehead sculptures have been found at Tenochtitlan, this one is particularly important for its preserved colors, said Erika Robles Cortés, an archaeologist with the INAH.

"Thanks to the context in which this piece was discovered, but above all, thanks to the stupendous intervention of the restorers-conservators led by Maria Barajas, it has been possible to stabilize the colors for its preservation in almost all the sculpture, which is extremely important, because the colors have helped us to conceive pre-Hispanic art from another perspective," Robles Cortés told Live Science in an email.

The sculpture's "sheer size is impressive, as well as its artistry," but the survival of the colors is remarkable, said Frances Berdan, a professor emeritus of anthropology at California State University, San Bernardino who was not involved with the excavation. "The survival of black, white, red, yellow, and blue paints is particularly interesting — one gains a good image of the visual impact of such sculptures as they were arrayed about the city center," Berdan said in an email.

In addition to its preserved colors, the snakehead's size is notable, said Bertrand Lobjois, an associate professor of humanities at the University of Monterrey in Mexico who is not involved in the excavation. The "first time I saw this serpent head, I was dazzled by its dimensions," he said in an email.

Lobjois also praised the conservation work that allowed the colors to survive, noting that "the conservation process allows us to appreciate the naturalistic approach of figuration" the Aztec artists used.

This work is ongoing and will continue at the site into next year.

By Owen Jarus.

[themakeupbrush]

Miss Universe Mexico 2023 National Costume

“Guardiana Alebrije”

[mirkobloom77]

‼️🇵🇸🎓🇲🇽 The students of the National Autonomous University of Mexico have joined the student encampments in support of Palestine!

🔸 Source: Dear_white_staffers

[xtruss]

The First Light of Trinity

— By Alex Wellerstein | July 16, 2015 | Annals of Technology

Seventy years ago, the flash of a nuclear bomb illuminated the skies over Alamogordo, New Mexico. Courtesy Los Alamos National Laboratory

The light of a nuclear explosion is unlike anything else on Earth. This is because the heat of a nuclear explosion is unlike anything else on Earth. Seventy years ago today, when the first atomic weapon was tested, they called its light cosmic. Where else, except in the interiors of stars, do the temperatures reach into the tens of millions of degrees? It is that blistering radiation, released in a reaction that takes about a millionth of a second to complete, that makes the light so unearthly, that gives it the strength to burn through photographic paper and wound human eyes. The heat is such that the air around it becomes luminous and incandescent and then opaque; for a moment, the brightness hides itself. Then the air expands outward, shedding its energy at the speed of sound—the blast wave that destroys houses, hospitals, schools, cities.

The test was given the evocative code name of Trinity, although no one seems to know precisely why. One theory is that J. Robert Oppenheimer, the head of the U.S. government’s laboratory in Los Alamos, New Mexico, and the director of science for the Manhattan Project, which designed and built the bomb, chose the name as an allusion to the poetry of John Donne. Oppenheimer’s former mistress, Jean Tatlock, a student at the University of California, Berkeley, when he was a professor there, had introduced him to Donne’s work before she committed suicide, in early 1944. But Oppenheimer later claimed not to recall where the name came from.

The operation was designated as top secret, which was a problem, since the whole point was to create an explosion that could be heard for a hundred miles around and seen for two hundred. How to keep such a spectacle under wraps? Oppenheimer and his colleagues considered several sites, including a patch of desert around two hundred miles east of Los Angeles, an island eighty miles southwest of Santa Monica, and a series of sand bars ten miles off the Texas coast. Eventually, they chose a place much closer to home, near Alamogordo, New Mexico, on an Army Air Forces bombing range in a valley called the Jornada del Muerto (“Journey of the Dead Man,” an indication of its unforgiving landscape). Freshwater had to be driven in, seven hundred gallons at a time, from a town forty miles away. To wire the site for a telephone connection required laying four miles of cable. The most expensive single line item in the budget was for the construction of bomb-proof shelters, which would protect some of the more than two hundred and fifty observers of the test.

The area immediately around the bombing range was sparsely populated but not by any means barren. It was within two hundred miles of Albuquerque, Santa Fe, and El Paso. The nearest town of more than fifty people was fewer than thirty miles away, and the nearest occupied ranch was only twelve miles away—long distances for a person, but not for light or a radioactive cloud. (One of Trinity’s more unusual financial appropriations, later on, was for the acquisition of several dozen head of cattle that had had their hair discolored by the explosion.) The Army made preparations to impose martial law after the test if necessary, keeping a military force of a hundred and sixty men on hand to manage any evacuations. Photographic film, sensitive to radioactivity, was stowed in nearby towns, to provide “medical legal” evidence of contamination in the future. Seismographs in Tucson, Denver, and Chihuahua, Mexico, would reveal how far away the explosion could be detected.

The Trinity test weapon. Courtesy Los Alamos National Laboratory

On July 16, 1945, the planned date of the test, the weather was poor. Thunderstorms were moving through the area, raising the twin hazards of electricity and rain. The test weapon, known euphemistically as the gadget, was mounted inside a shack atop a hundred-foot steel tower. It was a Frankenstein’s monster of wires, screws, switches, high explosives, radioactive materials, and diagnostic devices, and was crude enough that it could be tripped by a passing storm. (This had already happened once, with a model of the bomb’s electrical system.) Rain, or even too many clouds, could cause other problems—a spontaneous radioactive thunderstorm after detonation, unpredictable magnifications of the blast wave off a layer of warm air. It was later calculated that, even without the possibility of mechanical or electrical failure, there was still more than a one-in-ten chance of the gadget failing to perform optimally.

The scientists were prepared to cancel the test and wait for better weather when, at five in the morning, conditions began to improve. At five-ten, they announced that the test was going forward. At five-twenty-five, a rocket near the tower was shot into the sky—the five-minute warning. Another went up at five-twenty-nine. Forty-five seconds before zero hour, a switch was thrown in the control bunker, starting an automated timer. Just before five-thirty, an electrical pulse ran the five and a half miles across the desert from the bunker to the tower, up into the firing unit of the bomb. Within a hundred millionths of a second, a series of thirty-two charges went off around the device’s core, compressing the sphere of plutonium inside from about the size of an orange to that of a lime. Then the gadget exploded.

General Thomas Farrell, the deputy commander of the Manhattan Project, was in the control bunker with Oppenheimer when the blast went off. “The whole country was lighted by a searing light with the intensity many times that of the midday sun,” he wrote immediately afterward. “It was golden, purple, violet, gray, and blue. It lighted every peak, crevasse, and ridge of the nearby mountain range with a clarity and beauty that cannot be described but must be seen to be imagined. It was that beauty the great poets dream about but describe most poorly and inadequately.” Twenty-seven miles away from the tower, the Berkeley physicist and Nobel Prize winner Ernest O. Lawrence was stepping out of a car. “Just as I put my foot on the ground I was enveloped with a warm brilliant yellow white light—from darkness to brilliant sunshine in an instant,” he wrote. James Conant, the president of Harvard University, was watching from the V.I.P. viewing spot, ten miles from the tower. “The enormity of the light and its length quite stunned me,” he wrote. “The whole sky suddenly full of white light like the end of the world.”

In its first milliseconds, the Trinity fireball burned through photographic film. Courtesy National Archives and Records Administration

Trinity was filmed exclusively in black and white and without audio. In the main footage of the explosion, the fireball rises out of the frame before the cameraman, dazed by the sight, pans upward to follow it. The written accounts of the test, of which there are many, grapple with how to describe an experience for which no terminology had yet been invented. Some eventually settle on what would become the standard lexicon. Luis Alvarez, a physicist and future participant in the Hiroshima bombing, viewed Trinity from the air. He likened the debris cloud, which rose to a height of some thirty thousand feet in ten minutes, to “a parachute which was being blown up by a large electric fan,” noting that it “had very much the appearance of a large mushroom.” Charles Thomas, the vice-president of Monsanto, a major Manhattan Project contractor, observed the same. “It looked like a giant mushroom; the stalk was the thousands of tons of sand being sucked up by the explosion; the top of the mushroom was a flowering ball of fire,” he wrote. “It resembled a giant brain the convolutions of which were constantly changing.”

In the months before the test, the Manhattan Project scientists had estimated that their bomb would yield the equivalent of between seven hundred and five thousand tons of TNT. As it turned out, the detonation force was equal to about twenty thousand tons of TNT—four times larger than the expected maximum. The light was visible as far away as Amarillo, Texas, more than two hundred and eighty miles to the east, on the other side of a mountain range. Windows were reported broken in Silver City, New Mexico, some hundred and eighty miles to the southwest. Here, again, the written accounts converge. Thomas: “It is safe to say that nothing as terrible has been made by man before.” Lawrence: “There was restrained applause, but more a hushed murmuring bordering on reverence.” Farrell: “The strong, sustained, awesome roar … warned of doomsday and made us feel that we puny things were blasphemous.” Nevertheless, the plainclothes military police who were stationed in nearby towns reported that those who saw the light seemed to accept the government’s explanation, which was that an ammunition dump had exploded.

Trinity was only the first nuclear detonation of the summer of 1945. Two more followed, in early August, over Hiroshima and Nagasaki, killing as many as a quarter of a million people. By October, Norris Bradbury, the new director of Los Alamos, had proposed that the United States conduct “subsequent Trinity’s.” There was more to learn about the bomb, he argued, in a memo to the new coördinating council for the lab, and without the immediate pressure of making a weapon for war, “another TR might even be FUN.” A year after the test at Alamogordo, new ones began, at Bikini Atoll, in the Marshall Islands. They were not given literary names. Able, Baker, and Charlie were slated for 1946; X-ray, Yoke, and Zebra were slated for 1948. These were letters in the military radio alphabet—a clarification of who was really the master of the bomb.

Irradiated Kodak X-ray film. Courtesy National Archives and Records Administration

By 1992, the U.S. government had conducted more than a thousand nuclear tests, and other nations—China, France, the United Kingdom, and the Soviet Union—had joined in the frenzy. The last aboveground detonation took place over Lop Nur, a dried-up salt lake in northwestern China, in 1980. We are some years away, in other words, from the day when no living person will have seen that unearthly light firsthand. But Trinity left secondhand signs behind. Because the gadget exploded so close to the ground, the fireball sucked up dirt and debris. Some of it melted and settled back down, cooling into a radioactive green glass that was dubbed Trinitite, and some of it floated away. A minute quantity of the dust ended up in a river about a thousand miles east of Alamogordo, where, in early August, 1945, it was taken up into a paper mill that manufactured strawboard for Eastman Kodak. The strawboard was used to pack some of the company’s industrial X-ray film, which, when it was developed, was mottled with dark blotches and pinpoint stars—the final exposure of the first light of the nuclear age.

[kuramirocket]

Lead study Mexican author Luis Rodríguez, a professor emeritus at the Institute of Radio Astronomy and Astrophysics at the National Autonomous University of Mexico

In 2023, the James Webb Space Telescope (JWST) helped identify hundreds of free-floating "rogue" planets that don't orbit a parent star. Now, astronomers have found that a pair of these planets may be producing enigmatic, hard-to-interpret radio signals.

The rogue planets spotted by JWST lie in the Orion Nebula, a long-time observational hotspot for astronomers. In total, they number over 500. This discovery bonanza was possible thanks to JWST's ability to pick up infrared radiation emitted by these relatively young planets.

Bizarrely, though, about 80 of these planets exist as pairs. Similar in mass to Jupiter, the planets orbit each other at distances ranging from 25 to 400 times the distance between Earth and the sun. These tangoing duos, called Jupiter-mass binary objects (JuMBOs), pose a huge mystery for astronomers, because the existence of these worlds challenges current theories of planet formation. Some scientists think these objects may not even be planets but rather previously unknown entities that are larger than planets but smaller than brown dwarfs, which are sometimes called "failed stars" because they blur the line between planets and stars.

The JWST data showed that JuMBOs generated infrared radiation, but the new study's authors wanted to see if these dancing objects produced radio waves. That's because different classes of cosmic objects produce distinct patterns of radio emissions. For instance, planets like Jupiter spew several types of radio signals, including gigahertz-frequency emissions thousands of times higher-pitched than an FM signal, partly because of their magnetic fields.

Spotting such signatures from the JuMBOs could help resolve their identity. The observations could also explain "why some objects have detectable radio emission and others do not," lead study author Luis Rodríguez, a professor emeritus at the Institute of Radio Astronomy and Astrophysics at the National Autonomous University of Mexico, told Live Science in an email.

To find radio wave "snapshots" of the Orion Nebula where the JuMBOs reside, the scientists combed through archives of observations maintained by the U.S. National Radio Astronomy Observatory (NRAO). They found just one pair that apparently emits radio waves: JuMBO 24. Itself an oddity among the oddball objects, it's the heaviest of the JuMBOs, and also the one with the tightest space between its component planets.

A decade's worth of data the research team collated showed that the radio waves remained steady but strong, with a power of roughly a quarter of a ton of TNT and frequencies of 6 to 10 gigahertz. The radio waves also weren't circularly polarized, meaning they lacked spiral, twisting electric fields, the team reported in their study, published Jan. 8 in The Astrophysical Journal Letters.

But these features aren't what astronomers expect of signals created by planets." Circular polarization is an unambiguous indicator of the presence of magnetic fields," Rodríguez said. Without this, the team can't say definitively that the signals come from JuMBO 24 (assuming the planets have magnetic fields). Besides, radio emissions from other exoplanets are more variable and less intense.

Even if JuMBO 24 isn't a pair of planets but rather another type of cosmic duo, the signals are unusual. Signals from brown dwarfs are very different from the newly identified radio beams. The beams' brightness and frequency even ruled out the possibility of pulsars, the rapidly spinning cores of dead stars that produce pulses of radio waves at regular intervals.

The researchers also estimated the likelihood that the signals originate from an object behind JuMBO 24 and found it to be exceedingly slim, at just 1 in 10,000. And, in case you were wondering, the signals probably don't originate from aliens.  "The fact that both components emit at similar levels favors a natural mechanism," Rodríguez said.

With the research at an impasse, the team is applying to the NRAO's Very Large Array in New Mexico to collect data from free-floating planets. Until then, the radio signals will remain a mystery.

[disengaged]

nightmare shift today

[thepastisalreadywritten]

14 September 2023

[absmarchive]

Why we should learn from Mexican feminists

[quizranker]

Mexico Top University IQ Test #iqtest #freeiqtest #quiz #quiztime #quizg...

[mexicanistnet]

Royal and Pontifical University of Mexico, born in 1551, shaped by imperial whims, survived closures, and morphed into the National University. A saga of conquest, commitment, and bureaucratic flair unfolds over 471 years.

[thedigitalmuseum]

Art Sense Ep. 115: Museums of Tomorrow Roundtable

In April of this year, the Museums of Tomorrow Roundtable brought nearly two dozen museum directors from around the world together in Silicon Valley to discuss the evolving role of technology in museums. As dialogs between museum directors and technology leaders in Silicon Valley evolved, it became apparent that planning for the use of artificial intelligence had become a critical need.

On today’s episode, I’m honored to be joined by four museum executives who are an active part of these conversations about the future of museums:

Thomas P Campbell Director and CEO of the Fine Arts Museums of San Francisco

Seb Chan Director & CEO at the Australian Centre for the Moving Image in Melbourne, Australia

Amanda de la Garza Director General of Visual Arts at the National Autonomous University of Mexico in Mexico City and head of its University Museum of Contemporary Art

Suhanya Raffel  Executive Director, M+ Museum in Hong Kong

[radicalgraff]

"Palestinian resistance is not terrorism"

Stencil seen in the National Autonomous University of Mexico (UNAM) in Mexico City

[zvaigzdelasas]

US rice exports to Haiti, which account for the bulk of supplies of the country’s key food staple, contain unhealthy levels of arsenic and cadmium, heavy metals that can increase risks of cancer and heart disease, according to a recent study by the University of Michigan.

Haiti is among America’s top buyers of rice, alongside Mexico and Japan, and cheap imports are more affordable than local options in the Caribbean nation, the poorest state in the western hemisphere.

According to the study, average arsenic and cadmium concentrations were nearly twice as high in imported rice compared to the Haitian-grown product, with some imported samples exceeding international limits.

Nearly all imported rice samples exceeded the US Food and Drug Administration’s recommendation for children’s consumption. [...]

The study, which attributed the dominance of imported rice to lower import tariffs and long-term contracts signed during [US-supported] political turmoil in the late 1980s and 1990s, said Haiti imports nearly 90 per cent of its rice, almost exclusively from the US.[...]

When researchers ran the study in 2020, they found that Haitians on average consumed 85kg of rice per year, compared to 12kg in the US

23 Feb 24

[vylewa]

Over the last few weeks, I have been spending my time working on my save file because I'm gearing up to start a Let's Play series on Youtube. As I've been building the stories for the characters in my save file, I started thinking about the Sims universe as a whole and how I want my Sims to travel between worlds. It got me thinking that some worlds feel like they're just a short 4-hour car ride away, while others feel like you'd need a plane to get there.

So, I decided to map out my sims universe. I got a lot of inspiration from different Reddit posts as well as the EA descriptions of each world. This has been so helpful for me as I plan out the buildings I want to place in each world. It has been so helpful with finding inspiration for creating builds. I hope you can find this helpful too.

I'm really happy about my Sims universe turned out. I'd love to hear what you think about it! Are there any worlds you disagree with me on? Also, when are we getting an African world, EA?

North America

New Crest reminds me of suburban New York, mostly because you can still the city skyline from there.

Brindleton Bay reminds me so much of New England.

San Myshuno is quite obviously New York.

Willow Creek gives me a New Orleans vibe.

Magnolia Promenade is somewhere in the south because of the name (magnolias grow in the mostly in Southern United States - Mississippi, Louisiana, Alabama, Florida, Georgia, and South Carolina). I placed it close to Willow Creek for story telling purposes.

Chestnut Ridge gives me a strong Texas vibe.

Del Sol Valley is undoubtedly Los Angeles.

Oasis Springs I think of as Palm Springs with the desert and all, also the Langraabs live there.

San Sequoia I think of as San Francisco mainly because of the Golden Gate Bridge and Bay area, I have all my tech gurus living up there.

Strangerville is straight up Area 51 with all the weird stuff going on there.

Granite Falls gives me a National Park vibe, so I chose my favorite, Yellowstone which is mostly in Wyoming.

Copperdale seems to be in the rocky mountains, I placed it in Montana because of the old mining town description. Butte, Montana used to be a huge mining town.

Moonwood Mill reminds so much of the thick woods in the Pacific West somewhere Washington or Oregon.

Glimmerbrook I imagine is close to Moonwood Mill and the witches and the werewolves are always beefing.

Evergreen Harbor gives me a strong Pacific West port city like Vancouver (I know Vancouver is not in the US, but you get the drift).

Sulani reminds me so much of Hawaii, the beautiful beaches, volcanoes, and mountains and the culture portrayed by Sulanians.

Ciduad Enamorada reminds me so much of Mexico City, Mexico.

South America

Selvadorara gives a strong Amazonian vibe so I placed it in Brazil.

Europe

Britchester because of Britchester uinversity reminds me of Universtiy of Oxford, or University of Cambridge so I placed it in the UK.

Henford-on-Bagley gives off a strong English country vibe so I placed it South Central England.

Windenburg gives off a German vibe because of the style of buildings placed in the world.

Forgotten Hollow I think of as somewhere in Transylvania so I placed it in Romania.

Tartosa is undoubtedly mediterranean so I placed it in Italy.

Asia

Tomarang with the tuk tuks and the tiger sanctuary reminds me of Indonesia.

Mt. Komorebi, my absolute favorte world, is Japan. I can't wait to visit someday.

P.S. Batuu is not included in my sims universe because it is in space, I don't anticipate my sims ever traveling there, but if I ever feel otherwise, I will include it in here.

[xtruss]

Atomic Secrets: The Scientists Who Built The Atom Bomb 💣

Science and the military converged under a cloak of secrecy at Los Alamos National Laboratory. As part of the Manhattan Project, Los Alamos — both its very existence and the work that went on there — was hidden from Americans during World War II.

Many of the thousands of scientists on the project were not officially aware of what they were working on. Though they were not permitted to talk to anyone about their work, including each other, by 1945 some had figured out that they were in fact building an atomic bomb.

In 1943 J. Robert Oppenheimer was named the director of the Bomb Project at Los Alamos, a self-contained area protected -- and completely controlled -- by the U.S. Army. Special driver's licenses had no names on them, just ID numbers. Credit: Courtesy of the Los Alamos National Laboratory Archives

Robert Oppenheimer's wife Kitty was not above scrutiny. All who were affiliated with the project -- and their spouses -- were thoroughly screened and had a security file with the FBI. Credit: Courtesy of the F.B.I.

Less than a year after Oppenheimer proposed using the remote desert site for the laboratory, Los Alamos was already home to a thousand scientists, engineers, support staff… and their families. By the end of the war the population was over 6,000, and the compound included amenities like this barber shop. Credit: Time Life/Getty Images

Atomic Bomb Project employees having lunch at Los Alamos. Though food was often in scant supply, residents made the best of life in their isolated community by putting on plays and organizing Saturday night square dances. Some singles’ parties in the dormitories reportedly served a brew of lab alcohol and grapefruit juice, cooled with dry ice out of a 32-gallon GI can. Credit: Copyright Bettmann/CORBIS

Completely self-contained, the Los Alamos facility did not officially exist in its early years except as a post office box. Scientists’ families were mostly kept in the dark about the nature of the project, learning the truth only after the bomb was dropped on Hiroshima. Credit: Courtesy of the Los Alamos National Laboratory Archives

Credited with inventing the cyclotron, University of California-Berkeley physicist Ernest Lawrence (squatting, center) looks on as Robert Oppenheimer points out something on the 184” particle accelerator. Harvard University supplied the cyclotron that was used to develop the atomic bomb. Credit: Copyright CORBIS

The Trinity bomb was the first atomic bomb ever tested. It was detonated in the Jornada del Muerto (Dead Man’s Walk) Desert, near Alamogordo, New Mexico, on July 16, 1945. The test was a resounding success. The United States would drop similar bombs on Japan just three weeks later. Credit: Courtesy of the Los Alamos National Laboratory Archives

Oppenheimer and General Leslie Groves inspect the melted remnants of the 100-foot steel tower that held the Trinity bomb. Ensuring that the testing of a bomb with unknown strength would remain completely secret, the government chose a location that was so remote they had to import their water from over 150 miles away. Credit: Copyright CORBIS

Oppenheimer and General Leslie Groves stand in front of a map of Japan, just five days before the bombing of Hiroshima. Credit: Copyright CORBIS

Though there was no evidence that Oppenheimer had betrayed his country in any way, several officials called his loyalty into question in the Cold War environment of 1954. After being subjected to months of hearings, “the most famous physicist in the world” eventually lost his government security clearance. Credit: Reprinted courtesy of TIME Magazine

[kuramirocket]

Mexican scientist, Gerardo Ceballos, winner of the 16th edition BBVA Foundation Frontiers of Knowledge Awards in Ecology and Conservation Biology

The BBVA Foundation Frontiers of Knowledge Award in Ecology and Conservation Biology has gone in this sixteenth edition to two Mexican scientists who have documented and quantified the scale of the Sixth Mass Extinction, that is, the massive loss of biodiversity brought about by human activity. Gerardo Ceballos (National Autonomous University of Mexico, UNAM) and Rodolfo Dirzo (Stanford University) are hailed by the committee as “trailblazing researchers in ecological science and conservation,” whose joint work in Latin America and Africa “has established that current species extinction rates in many groups of organisms are much higher than throughout the preceding two million years.” In effect, by documenting losses of animals and plants in some of the Earth’s most biodiverse habitats, both have contributed to showing that today’s biodiversity crisis is, as the citation states, “an especially rapid period of species loss occurring globally and across all groups of organisms, and the first to be tied directly to the impacts of a single species, namely, us.”

The two awardee ecologists have catalyzed the global study of “defaunation,” a term Dirzo coined to describe the alterations causing the disappearance of animals in the structure and function of ecosystems. His research, says the citation, has revealed how the elimination of a single species can trigger pernicious “cascading effects” by disrupting the web of interactions it maintains with other organisms. This, in turn, has adverse effects on human wellbeing through the reduction of the goods and services they perform. His work has helped provide the “necessary scientific basis” to further the adoption of evidence-led conservation measures.

“The experimental work done by professors Ceballos and Dirzo has led the way in quantifying the extent of species loss,” explains a Research Professor in the Department of Integrative Ecology at Doñana Biological Station (CSIC) and secretary of the award committee. “And what is truly shocking about their results is that this species extinction rate, or ‘defaunation process’, as it is known, is advancing today at a speed several orders of magnitude above the rate recorded over the last two million years. This shows that we are up against a truly intimidating challenge; one that these two researchers have documented and assessed across thousands of vertebrate, invertebrate and plant species.”

Another committee member, a Research Professor in the Department of Biogeography and Global Change at the National Museum of Natural Sciences (CSIC) in Madrid, uses an analogy to highlight the importance of the awardees' work: “Imagine we are flying in a plane sitting next to the window. And looking out, we see bits of the plane falling off. It may not nosedive straight away, but the first thought that crosses the passenger’s mind is: how long can this plane keep flying without its component parts? Something similar occurs with ecosystems. As they lose their “parts'' or species, they also lose vital functions, and it is these functions that provide essential services. The work of Dirzo and Ceballos is a valuable addition to the understanding of how such losses affect the resilience and sustainability of our ecosystems, shedding light on the urgent need for conservation actions to preserve the integrity of these systems that are critical to our survival.”

An accelerating extinction rate driven by our own species

Ceballos and Dirzo's endeavors have advanced in tandem through most of their professional careers, with results in many cases complementing one another’s. But the origin of their collaboration lies back in the early 1980s, when both were studying at the University of Wales (United Kingdom), Dirzo pursuing his doctorate courses and Ceballos completing his master’s degree. They first connected over their shared concern at the increasingly evident impact on nature of human activity. “We started having conversations not just on scientific matters, but about how worried we were about the anthropogenic impact on the natural world we were seeing all around us,” Dirzo recalls.

Further ahead, Ceballos turned his research attention to the study of wildlife and the magnitude of the advancing extinction, while Dirzo centered his efforts on ecological interactions between plants and animals, and the consequences of this extinction.

Ceballos’ work on assessing current rates of extinction led him to explore comparisons with the rates of the past. “Evolution operates as a process of species extinction and generation,” he relates. In normal periods, more species appear than disappear, such that diversity gradually expands. There have been five mass extinction events in the last 600 million years, the last of which brought the demise of the dinosaurs. All had in common that they were catastrophic – wiping out 70% or more of the world’s species – had their origins in natural disasters, like a meteorite collision, and were extremely rapid in geological terms, lasting hundreds of thousands or millions of years.”

After a detailed analysis of numerous species, a research team led by Ceballos concluded – in a paper published in Science Advances in 2015 – that vertebrate extinction rates are from 100 to 1,000 times greater than those prevailing over the last few million years. “What this means is that the vertebrate species that have died out in the past 100 years should have taken 10,000 years to become extinct. That is the magnitude of the extinction,” he explains. His work pointed one way only; to the fact that the sixth mass extinction was already upon us, a scenario that for Ceballos has three major implications: “The first is that we are losing all that biological history. The second is that we are losing living creatures that have accompanied us through time and have been key in driving forward human evolution. And the third is that all these species are assembled in ecosystems that provide us with the environmental services that support life on Earth, like the right combination of gases in the atmosphere, drinking water, fertilization… Without these environmental services civilization as we know it cannot be sustained.”

The grave impact of extinction on ecosystem services

Species extinction is the last stage in the process, but Ceballos insists that population extinction is no less worrying, since it is these populations that provide environmental services on a local or regional scale. He gives an example: “It doesn’t matter if there are jaguars in Brazil if they have died out in Mexico, because the environmental services they performed in Mexico will have disappeared with them.”

Ceballos and his colleagues explored this concept in a study of prairie dog populations, which in the 1990s were thought to be pests and were the target of eradication campaigns. Through this study, published in 1999 in the Journal of Arid Environments, they were able to prove that, rather than pests, they actually play a vital role in maintaining their ecosystem, the grasslands of the southwest of the United States and north of Mexico.

“We found that prairie dogs were essential to the upkeep of ecosystem services, because if they are lost it sets off a chain of extinctions across the many other species who depend on them.” With these rodents gone, the soil becomes less fertile, erosion increases and the scrubland advances, wiping out the plants that serve as forage for livestock. “The impact on environmental services is colossal,” he affirms.

For the Mexican ecologist, the biodiversity crisis we are experiencing is of a magnitude similar to the crisis of climate change and both problems are closely interrelated: “We have to couple the issue of species extinction with the issue of climate change, and understand that it is a threat to humanity’s future.”

From deforestation to “defaunation”: the “cascading effect” of species loss

Rodolfo Dirzo states, "I was soon asking myself: these fascinating things I study, the ecology and evolution of plants and animals and their interactions, may not be around to study in future if we don’t start to do something about what is happening to natural systems.” This concern, which he shares with Ceballos, has guided Dirzo’s steps throughout his career, from Mexico to the United States.

By analogy with deforestation, he came up with the term “defaunation” to refer to the imbalance entailed by the absence of animals. “Everyone has a mental picture when they hear the word deforestation. They understand that what they are seeing is a problem, the erosion of ecosystems due to loss of vegetation. And it occurred to me that the word “defaunation” could be a way to highlight that, just as Earth’s ecosystems face a serious problem of deforestation, another serious threat lies in the depletion and possible extinction of animal species.”

The scientist began studying the effects of this phenomenon and published his findings in a chapter of the book Plant-Animal Interactions: Evolutionary Ecology in Tropical and Temperate Regions in 1991.

“Species do not live in an ecological vacuum,” he points out, insisting that it is not just species disappearances we have to worry about, but the extinction of species populations and, above all, species interactions, which should accordingly be a core focus of conservation actions.

Elephant poaching and the risk of pandemics

These effects, Dirzo explains, give rise to a phenomenon that he refers to as “winners and losers.” When these large animals die out locally, they are evidently losers, while smaller animals like rodents take advantage of their absence and therefore become winners. But these smaller animals also carry pathogens like Leptospira, Leishmania and even the bacteria that causes bubonic plague. So if populations of these pathogen-carrying animals increase, there is a greater chance that they will transmit diseases to humans. “We could be put at risk of suffering a new pandemic,” he affirms, “given the proliferation of these diseases and the current mobility of human beings.”

The researcher has verified these effects through experiments carried out in Africa. He and his team installed electrified fences in some very well-conserved parts of the savannah to stop large animals from entering. They then left other areas unfenced, so they could compare two identical ecosystems, one with large wildlife and one without. “We found that when an area is closed off to these animals, the savannah vegetation changes dramatically.” Further, the rodent population triples, as does the risk of diseases that can be transmitted to humans. In this way, he says, we get “a cascade that runs from elephant poaching to the real risk of a new human pandemic.”

In fact, it is not even necessary for a whole local population to die out for it to pose an ecological problem. If there are not enough individuals to maintain viable populations, the species in question can no longer interact with other organisms and fulfill its ecosystem function. It becomes what is known, says Dirzo, as a “living dead species.”

Hunting is just one human activity that can drive species populations totally or partially extinct and trigger such grave effects as a pandemic. Dirzo lists five key factors that drive defaunation: land use change for pasture or urban development; the overexploitation of resources; pollution – by anything from noxious chemical products to marine plastic waste; the introduction of non-native or invasive species in ecosystems where they don’t belong; and climate change. “But none of these five factors,” he adds, “operates in isolation: they are all interlinked, and this makes the challenge of dealing with biological extinction all the more complex.”

Laureate bio notes

Gerardo Ceballos (Toluca, Mexico, 1958) graduated in biology from the Universidad Autónoma Metropolitana-Iztapalapa (Mexico) and went on to earn master’s degrees from the University of Wales (United Kingdom) and the University of Arizona (United States), where he received his PhD in 1988. The following year, he took up a position at the National Autonomous University of Mexico (UNAM), where he is currently a Senior Researcher at the Institute of Ecology. He is the author of 55 books and numerous scientific papers, and some 200 applied studies in conservation and management that have featured in technical reports supported by institutions like the World Bank, the U.S. Agency for International Development or the State of Mexico Government. He is one of the forces behind Mexico’s endangered species legislation and the designation of over 20 natural protected areas covering more than 1.5 million hectares.

Rodolfo Dirzo (Cuernavaca, Mexico, 1951) completed a BSc in Biology at the Universidad Autónoma del Estado de Morelos (Mexico) then went on to obtain an MSc and PhD from the University of Wales (United Kingdom). Between 1980 and 2004 he held various teaching and research positions at the National Autonomous University of Mexico (UNAM), serving as a professor, Director of the Los Tuxtlas Biological Station and Chair of the Department of Evolutionary Ecology. In 2004 he joined the faculty at Stanford University, where he is currently Bing Professor in Environmental Science, Professor of Earth System Science, Senior Fellow at the Woods Institute for the Environment and Associate Dean for Integrative Initiatives in Environmental Justice. Dirzo has also taught in Argentina, Brazil, Canada, Chile, Colombia, Costa Rica, Nicaragua and Puerto Rico.

Nominators

A total of 47 nominations were received in this edition. The awardee researchers were nominated by Gretchen Cara Daily, Bing Professor of Environmental Science at Stanford University (United States) and 2018 Frontiers of Knowledge Laureate in Ecology and Conservation Biology.