Writing in The Conversation, Spear describes the exact feeling a lot of us experience in the gauntlet of massive holiday meals that end every year. Specifically, she examines them through the lens of the Japanese word “betsubara,” or “separate stomach.”

The Japanese have not discovered a second cow-like stomach in humans. The term is a silly colloquial way of describing the sudden and seemingly inexplicable desire to find room for dessert when there previously was no room for anything else. The sensation is real, Spear argues, but there’s nothing especially fascinating going on in our stomachs that makes room for sweet treats.

While our stomachs find a way to accommodate any desserts we put in them, our brains play a bigger role than you’d think.

The human stomach isn’t a rigid container that hits max capacity when it fills to the brim. It’s kind of elastic-y. When you eat, it relaxes through a process called gastric accommodation and expands without dramatically increasing pressure. Dessert is usually soft and mushy, low on fiber and protein, so it doesn’t take up a whole lot of space and doesn’t require much mechanical effort to digest. Ice cream is easier to make room for than a second steak, for instance.

Hunger doesn’t shut off once you’re physically full. What takes over is “hedonic hunger,” the urge to eat for pleasure rather than necessity. This is where your brain takes over. Desserts activate the brain’s reward system, releasing dopamine and temporarily quieting signals that tell your stomach you’ve had enough.

You may not need dessert, but your brain wants it — and it will perform all the complicated mental gymnastics necessary to convince you that it’s not just a good idea, but the best idea.

As you eat one type of food, your brain gradually finds it less rewarding. Switching to something sweet or creamy or both refreshes that response. That’s why someone who can’t finish their main course might still be able to find a little room for dessert. Their bellies may not be full, exactly, but they may be experiencing a kind of overstuffed sensory response that needs a little novelty to reset interest.

Fullness signals from hormones like GLP-1 and peptide YY take 20 to 40 minutes to fully kick in. Dessert decisions often happen before that system has caught up. Restaurants know this instinctively, offering menus while our natural reward system can still be exploited. Add cultural aspects, like how dessert is often seen as a celebratory act or part of a ritual, and then toss in a little bit of emotional eating when we need a sugary pick-me-up, and it’s easy to understand why, especially during the holidays, there’s always room for dessert.

The post Humans Have Grown a ‘Second Stomach’ Just for Desserts, Scientist Says appeared first on VICE.

Mark Dyble, an evolutionary anthropologist at the University of Cambridge, built what amounts to a mammal monogamy scale. Instead of relying on labels like “pair-bonded” or “socially monogamous,” he used something harder to spin. Siblings. Specifically, how often siblings share the same two parents. Using that measure, humans placed seventh among the mammals he studied.

“There is a premier league of monogamy, in which humans sit comfortably, while the vast majority of other mammals take a far more promiscuous approach to mating,” Dyble said in a statement.

Across the human societies included in the research, about 66 percent of siblings shared the same parents. That number puts humans in the same range as animals commonly described as socially monogamous, including Eurasian beavers and meerkats. It also places us far above several of our closest evolutionary relatives. Mountain gorillas came in at just over six percent. Chimpanzees landed around four percent, tied with bottlenose dolphins.

Dyble pulled the human data from two sources. One came from ancient DNA recovered at archaeological sites across Europe and Asia, mostly dating to the Neolithic and Bronze Age. The other relied on family trees compiled by ethnographers working with 94 pre-industrial societies. For other mammals, he used existing genetic studies detailed enough to show kinship structure and reproductive skew.

Humans Are Less Monogamous Than Beavers But More Monogamous Than Sheep

At the top of the list sat the California deermouse, which showed a perfect record of 100 percent full siblings. At the bottom were macaques, seals, and sheep, where shared parentage among siblings was rare. Humans landed in the upper tier, closer to wolves than primates.

“The finding that human rates of full siblings overlap with the range seen in socially monogamous mammals lends further weight to the view that monogamy is the dominant mating pattern for our species,” Dyble said.

The approach has limits. DNA only reflects relationships that produced children. Human reproductive behavior is shaped by contraception, social rules, and long sequences of partnerships that don’t always leave genetic traces. Dyble acknowledged that gap, noting that humans maintain “a range of partnerships that create conditions for a mix of full and half-siblings with strong parental investment.”

This ranking won’t tell anyone how to structure a relationship. It does suggest that, biologically speaking, humans behave more predictably than our cultural narratives imply. On a mammal scale, we cluster closer to beavers than chimpanzees, which is information people can sit with as they like.

The post Where Do Humans Fall on the Mammal ‘Monogamy Scale’? appeared first on VICE.

The conversation exploded after evolutionary biologist Jenny Graves published a commentary in 2004 suggesting the Y had lost most of its ancestral genes over hundreds of millions of years. Her rough estimate proposed that, if that pace continued, the chromosome could eventually disappear.

That was enough to launch years of headlines about the “end of men,” even though Graves never suggested anything that extreme. “It really amazes me that anyone is concerned that men will become extinct in 5 or 6 million years,” she told ScienceAlert, pointing out that humans haven’t even existed for a fraction of that time.

The Y chromosome’s history is undeniably messy. It once carried about 800 genes but retains only a small fraction today. Other mammals have already reinvented their sex-determining systems. Some mole voles lost the Y chromosome altogether and shifted key genes to other chromosomes. Spiny rats did the same and continue reproducing without issue. Graves sees these examples as proof that if a more efficient sex gene emerges in humans, it could spread without changing the visible traits associated with being male. “Maybe it already has in some human population somewhere,” she said.

But another camp sees the Y as far from doomed. Evolutionary biologist Jenn Hughes at MIT’s Whitehead Institute found that the essential genes on the human Y have remained stable for roughly 25 million years. Later studies of primates strengthened her position. Hughes explained that the surviving Y genes play crucial roles throughout the body, which creates strong evolutionary pressure to preserve them. In her view, the Y isn’t fading. It’s holding steady.

Graves pushes back, arguing that stability doesn’t equal permanence. The Y is packed with repeated sequences that can slip or degrade over generations, and conserved genes can still be replaced under the right conditions. She describes the Y’s timeline as “anything from now to never.”

When Hughes and Graves debated the issue publicly in 2011, the audience split evenly. That’s where things remain. The Y chromosome may endure unchanged for millions of years, or evolution may hand its job to another gene someday. Either way, there’s no countdown clock, no crisis, and no reason for men to draft farewell letters.

The post The Y Chromosome Might Disappear: What That Actually Means appeared first on VICE.

“This show is not for you”, says artist and performer Anne Hofstra as the audience take their seats in the theatre space at Amsterdam’s Mediamatic. “It’s for the chickens.”

Before the show even begins you can hear the humble flightless birds clucking and scrabbling around backstage. “When the curtain opens, you will be on the chickens’ stage,” says Hofstra. “Be aware of that. Don’t make big movements or noises. Let’s all radiate a calm energy that is as pleasant as possible to the chickens.”

This is Kip (Dutch for chicken), the play that was on everyone’s lips in the theatre circles of the Dutch capital. Written by playwright Doke Pauwels – and created in collaboration with Hofstra and artist Willem Wits – the play is centred around the idea that we have no idea what it’s like to be a chicken, and therefore don’t know for sure if a chicken would, or wouldn’t, enjoy art.

It all seems to gesture at a wider point about how humans have made plenty of incorrect assumptions about animal intelligence and consciousness, which are probably due a rethink. But while the premise might sound a bit tongue-in-cheek, the preparation included months of research into what chickens actually like, to the best of our human knowledge.

The show begins and Hofstra explains why she picked this animal among all the other options: Chickens have expressionless eyes and a rigid beak, and are therefore very difficult for us to read. Lots of people are a bit scared of birds in general, or simply think that there’s not much going on behind those beady eyes.“Chickens are much smarter than most people think,” she says. For example, continues Hofstra, they have some level of self-awareness, and can evaluate their circumstances and adjust their behaviour. Experiments have shown that a chicken will forego an immediate reward in favour of a delayed larger reward, which shows they have a rational grasp of self-control.

They also possess some logical abilities, like “transitive inference” (the capacity to deduce that if A is bigger than B, and C is bigger than A, then C will also be bigger than B), which is usually only acquired in humans by the age of 7.

Besides, chickens can recognise and distinguish between several other chickens and humans. They have a sense of time and can anticipate future events. They even have their own personalities, emotions and dreams, which means it’s likely they have an imagination. With all this considered, it’s suddenly not so outlandish to think they might enjoy a nice evening at the theatre. “Really interesting,” I hear someone whisper in the crowd.

The curtain lifts and three chickens scurry across the stage. Their participation in the play is strictly voluntary, and we are told that two of the five plumed actors didn’t feel like performing today. They’re sat outside in their pen.

Sharing the stage with the birds is Wits, the only human actor in this play, who walks around in a chicken suit the whole time. The stage is set up in two sections divided by a low fence, each side complete with stair-shaped scaffolding that the chickens use as a platform to hop on and off throughout the show.

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Wits has been informed by Hofstra on how to keep the birds’ attention. Throughout the performance, he walks with big strides, waving his arms and lifting his chicken mask over his head from time to time. The stage is includes a large white balloon, reminiscent of a huge egg, that periodically inflates and deflates. That’s my human interpretation, anyway – I can hardly imagine what the chickens saw.

Two of the chickens seem fascinated by everything Wits does. They sit as close to him as they can, right against the fence that separates them. The third chicken, which seems more bold in character than the others, continues to peck at the food bowl undisturbed. Every time the birds’ attention fades away, the curtains close, and Wits and Hofstra try out a new choreography. The human audience, meanwhile, watches in silence.

It feels childish to assume that you can please animals in the same way you please people, like putting on a pretend tea party for your cats. On the other hand, giving up completely on humanising animals as a way to connect with them might make us lose out on something big – particularly when it comes to better understanding our place alongside them in the world.

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In Hofstra’s opinion, just because we can’t fully understand an animal’s experience, that doesn’t mean we shouldn’t try to please them. She says it’s impossible to know if the chickens actually enjoy her work, but that’s not really the point.

Kip is primarily an attempt to think about a world that’s not centred on the human experience – a perspective that’s increasingly important in the face of the potential extinction of most life on earth. And it’s particularly significant to centre the narrative on the chicken, an animal frequently seen as a mere livestock commodity rather than a living, thinking being. If we had more respect for chickens, maybe our conversations around animal cruelty in the meat industry would shift.

In the climax of the show, Wits steps over the fence, lies down on the scaffolding, and reads a letter to the chickens. “Aw,” goes the audience as the birds rush towards him. They seem to be genuinely overjoyed that the actor, who looks like a very big chicken, is now among them. And by the end, they are all sitting on top of him.

The post I Went to a Theatre Show Written Specifically For, Uh, Chickens appeared first on VICE.

The results rewrite the timeline of Australopithecus, a family of early “hominins” that eventually gave rise to our own species, Homo sapiens, and resolve a longstanding debate over the age of fossils from Sterkfontein, an ancient complex cave system that contains more Australopithecus remains than anywhere else on Earth.

Researchers led by Darryl Granger, a professor of earth, atmospheric, and planetary sciences at Purdue University, concluded that “Australopithecus fossils from the richest hominin-bearing deposit…at Sterkfontein in South Africa are considerably older than previously argued by some,” in a study published on Monday in Proceedings of the National Academy of the Sciences.

The results show that the Sterkfontein individuals were contemporaries with Australopithecus afarensis, the species to which the famous “Lucy” specimen belongs, which refutes the “widely accepted concept” that these cave dwellers descended from A. afarensis, reports the study.

“The contemporaneity of the two species now suggests that a more complex family tree prevailed early in the human evolutionary process,” the researchers said in the new work. “The dates highlight the limitations of faunal age estimates previously relied upon for the South African sites.”

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Granger and his colleagues were able to produce this updated age estimate by examining the rock that encases Australopithecus bones, which contains the crystalline mineral quartz. Elements inside these quartz samples, including aluminum and beryllium, have been bombarded with cosmic rays, which are high energy particles that originate beyond the solar system.

These interactions create radioactive variations of those elements called isotopes—in this instance, aluminum-26 and beryllium-10—which decay in a clockwork pattern that is extremely useful for dating fossil remains. This method is more reliable than previous estimates based on stone deposits in the same sediment layer as the fossils, which produced an age of about 2.1 to 2.6 million years.

Because stones and fossils collapsed into some of the ancient cave layers together, some stones may originate from different eras than the fossils next to them. The team emphasized that the discovery demonstrates how intermixed sediment layers are in these sites, a feature that should factor into future research.

The updated age of these ancient human predecessors provides “a fuller picture of hominin presence and evolution in southern Africa, and increases “the geographic range and taxonomic diversity of hominins” during this period, the researchers said in the study. As a result, the research has opened a new window into the predawn of humankind, revealing the complex threads of our species and its extinct ancestors.

The post ‘Cradle of Humankind’ Fossils Are 1 Million Years Older Than We Thought, Scientists Say appeared first on VICE.

The immense family tree was stitched together from existing datasets and contains modern genetic information from around the world as well as samples from extinct human relatives such as Neanderthals and Denisovans. Scientists led by Anthony Wilder Wohns, who conducted the research while earning a PhD at the University of Oxford’s Big Data Institute, were able to confirm major events in human history from this integrated framework, such our species’ migration out of Africa, while also encountering surprises about past populations that will require more research to understand.

The outcome is a “unified genealogy of modern and ancient humans” that demonstrates the power of computational methods “to recover relationships between individuals and populations as well as to identify descendants of ancient samples,” according to a study published on Thursday in Science. Though this particular study is focused on humans, the team noted that the same approach could be used for almost any other species.

“The unified genealogy presented in this work represents a foundation for building a comprehensive understanding of human genomic diversity, including both modern and ancient samples, which enables applications ranging from improving genome interpretation to deciphering our earliest roots,” said Wohns and his colleagues in the study. 

A genome is a blueprint for how to make an organism, and every human carries a unique version of it in our cells. These genetic units contain a massive amount of heterogeneous information that is often generated by different techniques, which has long posed a computational obstacle for scientists hoping to combine various datasets.

One of the innovations of study is a new algorithm that can more efficiently collate all this information into a single genealogy or tree sequence. By revealing relationships between individuals and populations of humans that stretch back deep into our prehistory, the approach mapped out 231 million ancestral lineages of our human family over time, as shown in the below video.

The findings confirmed the timing of many migrations that are known from archaeological evidence, but there were a few unexpected implications in the data as well. For instance, the new family tree hints that humans first arrived in North America 56,000 years ago, much earlier than is currently estimated, and points to human migration to Papua New Guinea a full 100,000 years before the earliest documented evidence of habitation in that region. These tantalizing results do not necessarily mean that those migration timelines should be pushed back, but they do offer a compelling avenue of research going forward.

To that end, the team hopes to continue adding branches to this unprecedented family tree. While this initial version of the project contains genetic information from several thousand individuals, the researchers said this method could potentially accommodate millions of genomes in future iterations, providing an ever-evolving portrait of our vast human family.

“Although much work is still required to build the genealogy of everyone, the methods presented here provide a solution to this fundamental task,” the researchers concluded in the study.

The post Scientists Unveil ‘Unified Genealogy of Modern and Ancient Humans’ appeared first on VICE.

The extent to which other animals are similarly able to recognize themselves in mirrors is an area of heated debate in biology. While there’s consensus that some animals do recognize their reflections, such as chimpanzees, orangutans, and dolphins, studies of other species are not as clear-cut.

Case in point: For years, researchers led by Masanori Kohda, a biologist at Graduate School of Science in Osaka City University, have been on a quest to prove that the fish species Labroides dimidiatus, known as the cleaner wrasse, can recognize itself in a mirror, opening up the possibility that fish can be self-aware.

The team first reported their findings about these wrasses in a 2019 study in PLOS Biology, which caused controversy in the field, and now they are back with a follow-up study in the same journal aimed at proving their point.

Kohda and his colleagues came to the conclusion that wrasse can achieve mirror self-recognition by subjecting them to a famous experiment known as the mark test, in which an artificial mark is placed on the body of an animal while it is anesthetized. If the animal inspects the mark on its body in a mirror, or tries to touch it or remove it, it suggests that it has identified itself in the reflection, rather than mistaking the mirror image for some other individual.

While some mammals and birds have passed the mark test, Kohda and his colleagues were the first to claim that a fish had achieved this cognitive milestone. The researchers selected the cleaner wrasse specifically because the fish eats parasites off the skin of other animals and so is already attuned to recognizing strange marks in its environment.

“The cleaner fish (Labroides dimidiatus) is the only fish that passes the mark test, because other fish have no motivation to touch the mark” as the mark has “no meaning for other fish,” Kohda said in an email.

“This is because this fish is a cleaner fish that will pay attention to small parasites on other fish bodies and try to pick up and remove them,” he added, noting that the color mark is designed to resemble a parasite.

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The team’s initial results sparked pushback among some experts, prompting PLOS Biology to publish a primer suggesting that the fish experiment fell short of establishing mirror self-recognition, written by primatologist Frans de Waal, the C. H. Candler Professor of Psychology at Emory University and distinguished professor emeritus at the University of Utrecht.

In the years since this debate, Kohda and his colleagues ran their experiment again with new measures intended to address the critiques of the previous work. The researchers said that their updated results “increase our confidence that cleaner fish indeed pass the mark test, although only if it is presented in ecologically relevant contexts” in the new study, published on Thursday in PLOS Biology.

In the initial 2019 study, Kohda and his colleagues injected brown pigment into the throats of four fish while they were anesthetized, and then exposed them to a mirror. Three of the four test subjects scraped their throats against the tank substrate, as if trying to remove it. The team also performed alternate tests in which a transparent pigment was injected, which prompted no scraping behavior from the fish when presented with a mirror. When the brown pigment was injected and no mirror was present, the fish also did not exhibit the scraping response. Kohda and his colleagues therefore concluded that the fish had recognized themselves in the mirror based on their reaction to the brown pigment in their reflections.

Some of the main criticisms leveled at the 2019 study involved its small sample size of four individual fish and its conclusions that the fish were genuinely self-inspecting in the mirrors. De Waal also pointed out that the marking technique might have been physically irritating to the fish, which could muddy their reaction to their reflections by introducing a competing stimulus.

To counter those concerns in the new study, Kohda’s team increased the sample size to 18 individuals and experimented with different injection techniques to clarify whether the fish were scraping their throats due to irritation or self-recognition, or a combination of the two sensations. Instead of only injecting the brown pigment at a depth of one millimeter under the skin, they also tried placing it at a more invasive depth of three millimeters.

In this version of the test, the mark was barely visible and the fish scraped their throats regardless of whether or not a mirror was present, suggesting that they were reacting to the potentially irritating sensation of the deeper injection. However, fish with the shallower one-millimeter mark only scraped their throats when a mirror was present, hinting that the visual cue of the brown spot provoked the behavior rather than any sensations.

In addition, fish injected with green and blue spots, which don’t resemble parasites, did not exhibit the scraping behavior in front of the mirror. This finding further strengthens the evidence that the wrasse really do recognize themselves in the mirror, because they only took action to remove the spots that resembled parasites. Furthermore, Kohda and his team report that their experiment “shows the highest rate of passing with this large sample size,” with only one “failing fish” out of the 18 that took the test, according to the study.

In an email, de Waal said that many of his concerns with the initial 2019 study were sufficiently addressed by the new research, which he called “quite convincing.”

“I believe this experiment takes care of some of the questions I had last time,” de Waal noted. “I suggested then that *feeling* the mark might contribute to the self-recognition in the mirror as it involves two senses (sight and physical pain) instead of just one.”

“This new series of experiments takes care of this issue, showing that the reaction is color-dependent (which you wouldn’t expect if feeling the mark helps) and that a more painful (deeper) mark triggers a response w/o mirror, whereas the usual mark doesn’t,” he continued. “With these new experiments the evidence for [mirror self-recognition] is about as strong as it can get, and moreover shows that the marks need to be ecologically relevant in that they need to be of the color that cleaner fish generally respond to.”

That said, de Waal reiterated that cognitive abilities exist on a gradient, which is a perspective he had highlighted in his response to the 2019 study. While the mark test is one valuable way to probe intelligence in animals, de Waal suggests that there is some human-centric bias toward it simply because we are so familiar with reflections and mirrors and can relate to this form of self-awareness. He points to other techniques that are primed to study the concept of agency in animals, or to tests that play to the adaptations of the test subjects. For instance, scientists have demonstrated that dogs will smell their own scent longer in an “olfactory mirror” test.

“I still feel we would benefit from a gradualist perspective instead of the all-or-none approach to self-awareness,” de Waal said. “Why would awareness be the only cognitive trait in the animal world that appeared all of a sudden without any precedent and only in a tiny group of species, such as the hominids (humans and apes)? From an evolutionary perspective that’s an unreasonable assumption, but popular in some circles.”

Indeed, both Kohda and de Waal emphasized that these tests challenge the notion that humans are the only species capable of higher cognitive abilities such as self-consciousness.

“We do not know how many animals are intelligent exactly, and regard humans as the best intelligent organism in the world, that God made,” Kohda said. “But this is a large misunderstanding.”

“We do not properly understand animals!” he added.

To that end, Kohda and his colleagues plan to follow up on the study by trying to establish how the cleaner wrasse recognize themselves in the mirror, which he said is a “much more interesting question.” The researchers suspect that the fish are able to identify themselves by their faces, similar to humans, though it will take more experimentation to verify that hypothesis.

In the meantime, the new study reveals that these cleaner fish may have evolved a sophisticated sense of themselves that is potentially on par with animals that are much more familiar to humans, such as chimpanzees and orangutans.

“There will still be scientists who don’t want to take this seriously, but clearly, if a primate had shown all of these responses no one would be skeptical,” de Waal said. “These fish are remarkable!”

The post Fish Might Really Be Self-Aware, New Study Finds appeared first on VICE.

Scientists have been tracking the rise of marine heat waves, which are short-lived pulses of intense heat in specific regions, but less is known about the general long-term pattern of extreme marine heat across the entire ocean surface. To bridge this knowledge gap, a pair of marine ecologists built a map of sea surface temperatures that dates back 150 years, which revealed that a “new normal” of extreme heat in the global oceans began in 2014, according to a study published on Tuesday in PLOS Climate.

The results are a “wake-up call,” said study co-author Kyle Van Houtan, who conducted the research while he was chief scientist at Monterey Bay Aquarium, in a call. 

“You cannot overestimate the stabilizing and significant force of the ocean in making our planet habitable for all of our lives,” added Van Houtan, who is now president and CEO of Loggerhead Marinelife Center in Florida. “It’s telling us, right now, that it is out of balance. It is extremely hot.” 

Van Houtan and first author Kisei Tanaka, who is a research marine biologist at the National Oceanic and Atmospheric Administration (NOAA) in Hawaii, were inspired to develop the new study at Monterey Bay Aquarium after examining the decline of kelp forests off the coast of California. While combing through historical records of these marine forests, the team realized that there was no coordinated index or map of extreme heat data, based on sea surface temperatures, that extended back in time to the late 19th century.

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To create this comprehensive historical benchmark, Tanaka and Van Houtan drew on two datasets that date to 1870. The researchers reviewed temperatures logged between 1870 and 1919, and recorded what the peak temperature was for each month to create a map of extreme heat during that 50-year period.

“These are rigorous contemporary indices,” said Takana in an email. “We didn’t make these indices, but we apply them in a unique way. We used the 1870-1919 baseline to highlight the centennial-scale of these global datasets, but anyone can come up with different baselines to define their new normals.”

The historical baseline that the team established showed that extreme surface temperatures occurred in about two percent of the world’s ocean around the turn of the 20th century. By contrast, more than 50 percent of the global ocean have crossed this extreme heat threshold every consecutive year since 2014—with the number reaching 57 percent in 2019, the last year covered in the study—marking what Tanaka and Van Houtan called “a point of no return.”

Moreover, the team discovered that some regions have long since crossed this point where extreme heat is a new normal: For instance, the South Atlantic reached this threshold in 1998 and the Indian Ocean crossed it in 2007.

“This is important because if you take a step back and you look at the public discourse on climate change, it’s about future uncertainty,” Van Houtan said. “What our study finds is this is not some hypothetical future event or phenomena that may or may not occur. This is something that’s a historical fact. It’s already happened. We’re living in an extremely hot world in the ocean as of 2014, and in some regions of the ocean, a couple of decades earlier.” 

Given the alarming acceleration of extreme heat in such huge swaths of the ocean, it’s not surprising that marine ecosystems are struggling to adjust to a much hotter environment. In some cases, rising temperatures are driving migrating species to new territories in cooler waters at higher latitudes. Other vital ecosystems, such as coral reefs, are dying off as temperatures exceed their survival thresholds, causing once-vibrant biological hotspots to become inhospitable to many species.

“All organisms have a physiological limit,” Van Houtan said. “They have constraints, and extremes hit on those constraints. The more often they occur, the more constrained organisms and species—plants and animals in the ocean and on land—are going to be adversely affected. And that’s what we’re seeing.”

This mass disruption of marine environments is, of course, a troubling trend in its own right, but these changes also have major implications for human lives and livelihoods. Tanaka and Van Houtan found that extreme heat is intruding into many ocean regions that are economically important, which will restrict production from fisheries and other industries. Tanaka has already had a front-row seat to one of these disruptions, during his PhD at the University of Maine. 

“The Gulf of Maine was experiencing one of the fastest-warming rates globally, and lobster was the biggest fishery in the US by value,” he said. “Naturally, I did my dissertation on climate change and US lobster fisheries.” 

“The 2012 Gulf of Maine heatwave gave us a really eye-opening case study of how climate-driven changes in the commercially valuable species biogeography threw off the entire lobster fisheries system,” Tanaka continued. “This is just one case study, but we can expect similar outcomes from future extreme heat events.”

In this way, the new study adds to the overwhelming evidence that human-driven climate change is not only wreaking havoc on marine species, it is also a major threat to human societies across the globe.

“Any discussion of climate change that doesn’t begin and end with the ocean probably needs to be reframed,” Van Houtan said. “It’s 97 percent of the water on our planet. It generates the primary source of protein for two to three billion people every day. It provides medicine and good stable jobs.” 

“It is the beating heart of our climate system, and it needs to be at the forefront of any climate discussion,” he concluded.

Update: This article has been updated to include comments from study lead author Kisei Tanaka.

The post Extreme Heat is the ‘New Normal’ in Earth’s Oceans, Study Warns appeared first on VICE.

Now, a team led by Robert Cowie, research professor at the University of Hawaii’s Pacific Biosciences Research Center, argues that “the Sixth Mass Extinction has begun on land and in freshwater seems increasingly likely,” according to a recent article published in Biological Reviews.

“We consider that the Sixth Mass Extinction has probably started and present arguments to counter those who would deny this,” said the team, which also included biologists Philippe Bouchet and Benoît Fontaine of the Muséum National d’Histoire Naturelle in Paris, France, in the article.

“Denying it is simply flying in the face of the mountain of data that is rapidly accumulating, and there is no longer room for skepticism, wondering whether it really is happening,” added the authors.

Cowie and his colleagues refer to a multitude of studies cataloging the extinction of species across clades, but the article is primarily built around their research into mollusks, an invertebrate family that includes snails, clams, and slugs. This focus counteracts the disproportionate attention that vertebrates, such as birds and mammals, receive in the International Union for Conservation of Nature (IUCN) Red List of Threatened Species, among other conservation efforts.

“The IUCN information on the extinction of birds and mammals is probably quite accurate,” said Cowie in a call. “However, they have not evaluated any but a tiny, tiny fraction of invertebrates such as insects and snails and spiders and crustaceans, which constitute 95 percent of animal diversity.”

As a result, invertebrates provide “more of a random sample of biodiversity,” he noted.

Past studies have used IUCN data to refute the notion that we are entering a Sixth Mass Extinction. Cowie and his colleagues pushed back on this assumption by compiling extinction rates of land snails and slugs. Extrapolating from those data, the team concluded that anywhere from 7.5 and 13 percent of species may have become extinct since the year 1500, a figure that is in line with many other estimates that suggest catastrophic biodiversity losses due to human pressures.

“The bottom line is that all these estimates that people have made indicate a much higher rate of extinction now than in the past,” Cowie said.

This extinction crisis is far more pronounced on land than in the oceans, according to the article, though many marine species are also threatened as the result of human activity. Extinctions are also generally occurring much more rapidly in island ecosystems, such as Hawaii, compared to continental biomes.

In addition to raising alarms about a possible mass extinction, Cowie and his colleagues address a range of counterarguments that they say downplay the severity of human pressures on world species, or even suggest that humans should harness these ecological changes for our own benefit.

The team argues that this kind of “laissez-faire attitude to the current extinction crisis is morally wrong,” according to the article, and advocates for more urgent measures to address the loss of species due to human activity.

“I feel obligated to express opinions about what we feel should be done given this crisis situation,” Cowie said. “I’m not just going to present the data and say be done with it. I’m going to say what we should do to resolve this issue, because it’s an important issue.”

Ultimately, the team acknowledges that conservation efforts can feel futile in the face of this massive problem, and suggests that more energy should be spent on efforts to gather specimens of disappearing species before they are lost forever.

“We don’t think there’s a positive ending; we think it’s kind of a disaster,” Cowie concluded. “We feel that the most important thing we can do for the future is to preserve as many of these species as possible in museums, so that in 200, 300, or 500 years from now, people will still be able to say this is what the Earth once had. I strongly believe that.”

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The groundbreaking discovery provides “definitive evidence of human occupation of North America” during the Last Glacial Maximum (LGM), when ice sheets extended as far south as New York City, while also shedding light on the “coexistence” of these communities with extinct animals such as giant ground sloths and mammoths, according to a paper published on Thursday in Science. 

Though these tracks have been known about for years, a team of scientists have now constrained their exceptional age by radiocarbon-dating two layers of preserved aquatic seeds deposited above and below them.

“If you’d asked most people in the archaeological community a few years ago what the earliest site in the Americas would look like, we would have said we’d need hearths that could be dated; a few human teeth would be great so we could do genetics work; and some other human bones would be fabulous, and definitely some older-looking stone tools,” said Sally Reynolds, a mammalian paleontology at Bournemouth University who co-authored the study, in a call.

“Yet here we have the story of the earliest human presence in North America being told without stones, bones, or hearths, but by footprints and two seed layers,” she continued. “It shows you that in science, one has to be very open to the wealth of evidence that you sometimes get when you do archeological excavations.” 

The White Sands footprints are known as “ghost tracks” because they are only visible in certain light and moisture conditions. Reynolds and her colleagues have been studying the fossils for the past five years, and have already published research indicating that humans in this area stalked and harassed sloths, offering a rare look at the behavior of both species during this period. 

However, the new study is the first to definitively confirm the unprecedented age of these footprints, a finding that has widespread implications for reconstructing the mysterious origins of humans on the North American continent. 

The advance of ice during the LGM blocked migration routes from Asia into North America, prompting many scientists to doubt that our species could have arrived on the continent earlier than about 16,500 years ago, when these barriers receded. However, tantalizing potential traces of humans before that timeframe have turned up here and there, suggesting that a small population may have migrated to the continent before the LGM. 

Reynolds and her colleagues, including lead author Matthew Bennett also of Bournemouth University, have now presented the most robust evidence that humans were able to slip through to the continent before the glacial portcullis was drawn up.

“Our work has shown that the ice sheets were probably controlling entry into North America, but that we had made it in one glacial cycle earlier,” Reynolds said. “Working back from that, we think that at around 30,000 years ago, humans would have traveled from Siberia over the Bering land bridge.”

“This migration route only existed when there was some ice to lower the sea levels, but not enough ice to close the two ice sheets, so that constrains some of our timing,” she added. “It is a very exciting step change in how we understand the stages of this most important migration into North America.”

In addition to stretching back the empirical timeline of humans on the continent, the footprints contain insights about the people who lived in White Sands so many millennia ago. A lot of the tracks were made by children, which is a bias that exists in other human footprint sites around the world. Like kids today, these youngsters were probably running around, stomping, and playing more than adults, thereby leaving more footprints behind. Likewise, many of the tracks also belong to teenagers who might have been carrying out tasks on behalf of older members of their community, or just idling around together.

The presence of mammoth and sloth tracks alongside the human footprints also implies that humans during this period were hunting enormous prey. While overhunting by humans has been implicated in the later extinctions of these large animals, the White Sands tracks suggest that this earlier population managed their prey sustainably over a period of about 2,000 years, probably because it was so much smaller than later migrations.

Now that the researchers have snagged such compelling proof that humans inhabited North America prior to the LGM, they are eager to search for more traces of these trailblazers in places like Alaska, a major gateway to the continent, as well as in White Sands, where these ghost tracks have just opened a new window into our shared human past.

“It’s just mind blowing the level of information we could actually get from this site, and I’m really excited at what the future will bring,” concluded Reynolds. “That’s why we’re also pleased that we might be able to tell the world about this and then move on, because we’re so excited to focus on the future work.”

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