Image credit: David McClenaghan, CSIRO, via Wikimedia Commons
Bees have long impressed behavioral scientist Lars Chittka. In his lab at Queen Mary University of London, the pollinators have proven themselves capable of counting, using simple tools, and learning from nestmates. What really surprised Chittka, however, were the nuances of the insects’ behavior.
In 2008, for instance, a study from Chittka’s lab looked at how bumblebees reacted to a simulated attack by a fake spider on a flower. The bumblebees later approached suspect flowers cautiously and sometimes left even spider-less flowers quickly “as if they were seeing ghosts,” Chittka recalled. By contrast, the bees were seemingly more upbeat after receiving a sugar treat.
To Chittka, these observations defy a long-held view that insects are robot-like, controlled by hard-wired cognitive programs. Rather, the bees’ behavior seemed to be influenced by subjective experience — a perception of pleasant and unpleasant. Chittka said he increasingly suspects “there’s quite a rich world inside their minds.”
Early in his career, Chittka never protested when his colleagues opened bees’ skulls and inserted electrodes to study their nervous system. But he now wonders whether such procedures might create “potentially very unpleasant situations” for the insects. Like most invertebrates — any animal without an internal skeleton — insects tend to be legally unprotected in research. Regulations intended to minimize suffering in vertebrates like rodents largely don’t apply.
Some countries have already improved the welfare of select invertebrates, such as octopus, squid, crabs, and lobster. But there’s disagreement over whether other invertebrate species — a kaleidoscopically diverse cast of animals — also deserve protection. Some scientists believe species with relatively simple brains, like insects, or perhaps even those with no central nervous system at all, also deserve ethical consideration, although the details are under debate.
None of the experts who spoke with Undark argued that research on these invertebrate species should stop. Some organisms, including widely used species of fruit flies or nematode worms, have long led to breakthroughs in genetics, cell development, and other biological processes, and have played important roles in roughly a fifth of Nobel Prizes for Physiology or Medicine that were based on animal research. Many scientists are also shifting their research from vertebrates to invertebrates to avoid ethical bureaucracy associated with animal welfare regulation.
Still, recent research is prompting some scientists to rethink traditional research ethics. As Adam Hart, an entomologist at the University of Gloucestershire, put it: “I think we are at a point where people are willing to entertain the idea that perhaps ethics isn’t just something for animals with backbones.”
Read the whole story in Undark, Popular Science or in The Atlantic
This picture illustrates a scene from northern Laurentia (North America) in the period a few weeks after the Chicxulub impact showing the onset of freezing weather and skies loaded with sulfur aerosols. The focus is on the last surviving dinosaurs – here a pair of T-Rex chicks, which somehow survived the initial impact phenomena, but which will soon succumb to the cold. Credit: ©James McKay – Creative Commons
“You wouldn’t have lasted long, I don’t think, as a puny human swimming around in this ocean,” muses paleontologist and geologist James Witts while viewing an artist’s depiction of marine life during the Cretaceous Period on his computer screen. Starting around 145 million years ago, this was the last age of the dinosaurs. As on land, the food web of these ancient seas was likely dominated by gigantic reptiles. Along with sharks, many of these now-extinct species may have feasted on bottom-dwelling crustaceans and free-swimming cephalopods and fish.
Today, the fossilized remains of these creatures are buried beneath a conspicuous layer of sediment or rock that geologists call the Cretaceous-Paleogene (K-Pg) boundary. The layer is typically enriched in the element iridium, released by the shattering of the Mount Everest–sized asteroid that smashed into modern-day Mexico one fateful day 66 million years ago and brought the Cretaceous period to a violent end. “It basically happened in the worst possible place,” says Witts, a lecturer at the University of Bristol. Research published earlier this year by him and his colleagues suggests that massive quantities of sulfur from bedrock at the impact site, in the present-day Yucatán peninsula, were blasted into the atmosphere, creating aerosols that blocked sunlight for several months, cooled the climate for decades, and fell down as acid rain—all contributing to the collapse of global ecosystems. The fossil record falls comparatively silent after the K-Pg boundary, as an estimated 76 percent of marine species were wiped out, for instance. And as life recovered over the next million years, only a subset of the lineages that previously roamed the Earth were among its ranks. Like their popular terrestrial counterparts, “the big marine reptiles—they never come back,” says Witts.
The K-Pg extinction is the most recent of five events in Earth’s history that scientists consider mass extinctions, defined by paleontologists as events where more than 75 percent of species vanish within a geologically short period of time, typically less than two million years. The four previous mass extinctions were also thought to have involved climatic changes—due to large-scale volcanic eruptions, for example—and in one case obliterated all but 5 percent of species. (See illustration below.) In between these events were smaller extinction episodes and periods of relative stability, with new species often arising at rates that compensated for species losses.
Now, many scientists fear that the next ordeal of this scale is close—this time around, caused by our species, which sprang onto the scene within the last few hundred thousand years. Although we’re still far away from reaching the 75 percent mark, extinction rates are climbing, and many more species appear to be on the brink. Scientists point to the worldwide destruction of natural habitats and the exploitation of wild species, along with climate change, pollution, and ecological disruption caused by the spread of invasive organisms, as driving factors. Indeed, Witts says he reckons that the sheer speed of environmental change today is similar to that caused by the asteroid.
Whether current biodiversity loss—a crisis by any measure—meets the criteria for another mass extinction is hotly debated. Much of the debate hinges on accurately measuring the scale of modern-day and prehuman extinction, which is complicated by an incomplete understanding of present and past biodiversity. Some scientists also question whether diagnosing a mass extinction is even relevant.
“We’re in this really unusual position, where, for the first time, we are trying to put our finger on a geologically superlative event while it’s happening,” says Jacquelyn Gill, a paleoecologist at the University of Maine. However, when it comes to biodiversity loss, “just evoking the fact that our influences could even be on the scale of a comet or some of these other big events in the past—I think that should be giving us pause.”
Read more at The Scientist.com
Image credit: Grist
As a 10th-grader growing up in Bergen, Norway, Mia Chamberlain dreaded when her science class lesson was on climate change. She’d often skip those classes or sneak out of the classroom. She couldn’t handle the fear when confronted with projections of scorching droughts and devastating floods — a future that she would have to live through, despite having grown up in a country as wealthy and safe as Norway. It was like the breathless, stomach-churning feeling of being broken up with, the moment a future vanishes. She couldn’t understand how her science teachers could discuss it with the same detached calm of instructing an algebra class. “It was like sitting through a horror movie that you really don’t want to be watching,” said Chamberlain, who is now 23.
Around that time, nearly 2 million barrels of oil and other fossil fuels were being drilled each day from Norway’s continental shelf, much of it sold elsewhere. Adults around her didn’t seem to understand Chamberlain’s frustration. She felt afraid, lonely, angry, anxious, and deeply unhappy — a tide of emotions she now describes as climate anxiety, a diagnosis that is receiving more and more attention from scientists, psychologists, and now, courts.
Cabernet grapes at the UC Davis Oakville research station in Napa Valley. Credit: Katarina Zimmer
Soon after the devastating Glass Fire sparked in California’s Napa Valley in September 2020, wine chemist Anita Oberholster’s inbox was brimming with hundreds of emails from panicked viticulturists. They wanted to know if they could harvest their grapes without a dreaded effect on their wine: the odious ashtray flavor known as smoke taint.
Oberholster, of the University of California, Davis, could only tell them, “Maybe.”
Industry laboratories were slammed with grape samples to test, with wait times of up to six weeks. Growers didn’t know whether it was worth harvesting their crops. Eight percent of California wine grapes in 2020 were left to rot.
Winemakers are no strangers to the vicissitudes wrought by climate change. Warmer temperatures have been a boon to some in cooler regions who are rejoicing over riper berries — but devastating to others. Scorching heat waves, wildfires and other climate-driven calamities have ruined harvests in Europe, North America, Australia and elsewhere.
And as 2020 showed, climate change can take its toll on grapes without directly destroying them. Wildfires and warmer temperatures can transform the flavor of wine, whose quality and very identity depends on the delicate chemistry of grapes and the conditions they’re grown in. Many growers and winemakers are increasingly concerned that climate change is robbing wines of their defining flavors, even spoiling vintages entirely.
“That’s the big worry,” says Karen MacNeil, a wine expert living in Napa Valley and author of The Wine Bible. “That’s the heartbeat of wine — it’s connected to its place.”
The greatest challenge that climate change brings to winemaking is unpredictability, MacNeil says. Producers used to know which varieties to grow, how to grow them, when to harvest the berries and how to ferment them to produce a consistent, quality wine — but today, every step is up in the air. This growing recognition is spurring researchers and winemakers to find ways to preserve beloved grape varieties and their unique qualities under the shifting and capricious conditions of today’s warming world.
To learn about the threats to our favorite beverage, we spoke with wine experts from two renowned wine regions — Bordeaux in France and California — to understand how climate change is uprooting their traditional vines and wines, and traveled to the University of California, Davis, and nearby Napa Valley in late 2021 to speak with scientists, growers and winemakers.
We were treated to an inside look at how every stage of winemaking is transforming to preserve desired flavors and aromas — and yes, got to taste a lot of wine, from the finest Cabernet Sauvignon to samples spoiled by smoke and scorching heat.
Read the rest of the story, co-reported with Ula Chrobak, in Knowable Magazine and The Atlantic.
Image credit: Ebrahim, EmojiOne via Wikimedia Commons
I recently started asking scientists I interview if they have any questions about the journalistic process. It turns out that they have a lot! So I wrote about common issues scientists have with journalists and how to improve this vital relationship; read my story in The Scientist.
Image: A view inside the department of zoology and animal ecology at Kharkiv National University. The institution’s main building lost many of its windows due to a shockwave following a rocket attack on nearby official infrastructure. Credit: Glib Mazepa
My latest is about the impact of Russia’s invasion on Ukraine’s scientific community, and efforts to keep science going amid the horror that’s unfolded since. I’m so grateful to everyone who shared their story – from universities providing humanitarian aid, scientists scrambling to rescue years’ worth of research, and clinical trial leaders finding other ways for patients to get needed treatments. Please read, at The Scientist!
Image: Nancy Thomas
Once upon a time, people near the valley of Nemea in southern Greece lived in mortal fear of a lion lurking in the surrounding hills and preying on the populace. Only mighty Hercules, challenged by the king of nearby Tiryns, could slay the beast.
The son of Zeus cornered the powerful carnivore in a cave and choked it to death with his bare arms. Thereafter, the people lived in peace, and Hercules continued his famed adventures.
Of course, the Nemean lion story is a mere fable, part of an eclectic cast of gods, heroes, and fantastic beasts that populated the myths of antiquity. There are certainly no wild lions in Europe today.
But early 20th-century archaeologists in mainland Greece thought that there might be some truth to the existence of lions in the region in ancient times. Why else do these creatures feature so prominently—and realistically—in art from the late Bronze Age, as well as myths and actual reports by later scholars from the Classical period, such as Aristotle and Herodotus?
Though such theories were long dismissed by other researchers, in 1978, two prominent German zooarchaeologists made a startling discovery. During an excavation of Tiryns—the same city whose legendary king dared Hercules into action—they chanced upon a feline heel bone near a human skeleton. It was unmistakably from a lion, they concluded, and possibly of the same species that inhabits parts of the African continent today.
The bone was only the first of dozens to surface in Tiryns and elsewhere over the following decades. Though some details remain unclear, many archaeologists and historians now use this evidence to conclude that modern lions once lived alongside people in parts of what is today Europe, including Greece, for hundreds of years. Today lion bones offer a rare glimpse into the Bronze Age world and the fraught relationship humans had with these fierce predators, animals that inspired legends and creative works for centuries.
“Now it’s possible to say that some [lion images] could have been recalled from real experiences on the [Greek] mainland,” says art historian Nancy Thomas. The finds, she adds, cast “a whole different light on the art … and how hunting real lions could have played into the elite structure development that was going on in Greece at the time.”
Keep reading in Sapiens
Image: WelshDave, Wikimedia Commons
Hedgerows are as British as fish and chips. Without these walls of woody plants cross-stitching the countryside into a harmonious quilt of pastures and crop fields, the landscape wouldn’t be the same. Over the centuries, numerous hedges were planted to keep in grazing livestock, and some of today’s are as historic as many old churches, dating back as far as 800 years. Today, Britain boasts about 700,000 kilometers (435,000 miles) of them, a length that surpasses that of its roads.
In recent years, ecologists — especially in Britain, Ireland and continental Europe, but also in places that have more recently adopted hedgerows, such as California — have come to view these man-made structures as important ecosystems in their own right. They form a vital reservoir of biodiversity in human-dominated landscapes where many species might otherwise struggle to survive. By nurturing pollinating insects, they can enhance the yield of crops. And they do it all while pulling carbon out of the atmosphere.
This growing ecological appreciation is invigorating efforts in many regions to expand hedgerows, or hedges, and so help combat both the biodiversity and climate crises. More hedgerows, ecologists and policymakers hope, could provide a mutually beneficial way for farming to coexist with nature.
“Most people just drive or walk past hedgerows and maybe don’t think about them very much,” says Jo Staley, an ecologist at the UK Centre for Ecology and Hydrology, a nonprofit research institute. “But when you start to learn a bit about them, you see the potential.”
Read the whole story at Knowable Magazine
Image: Martin Picard
Mitochondria have shelflike internal membrane folds called cristae. Picard’s research group observed that when mitochondria touch, their cristae can line up on either side of the membrane.
During his doctoral research on the ties between aging and mitochondria, Martin Picard frequently saw micrographs of those energy-producing organelles. Yet it wasn’t until fairly late in his graduate work that he first watched sped-up video of mitochondria moving inside live human cells, and the sight came as a revelation.
Tagged with fluorescent dye, the mitochondria were neon squiggles crawling through the soupy interior of the cells — stretching and contracting, fusing together and splitting up again, sidling up to one another and parting ways. Their apparent eagerness to network reminded Picard of the social exchanges among complex creatures like fish and ants. “They just look a little more primitive,” he said.
Now, after years of work in his own laboratory and others that has underscored the importance of those dynamic mitochondrial interactions, he is pressing that comparison more literally. Recently, in Neuroscience & Biobehavioral Reviews, Picard, a mitochondrial psychobiologist at Columbia University, and the neuroscientist Carmen Sandi of the Swiss Federal Institute of Technology Lausanne argued that mitochondria need to be understood as the first known social organelles.
As evidence, they cite a long line of discoveries showing that mitochondria are surprisingly interdependent and that their functions go far beyond their familiar role as cellular powerhouses: Mitochondria also make certain types of hormones, help drive immune responses, and shape the developmental fate of cells. To these diverse ends, like ants in a colony, mitochondria divide up tasks, form groups, synchronize activities and respond to both their environment and each other. A “social lens,” Picard and Sandi wrote, may be essential not only for explaining the behavior of individual mitochondria, but for revealing the mitochondrial collectives that influence human health.
Despite some reservations about the label “social,” other scientists generally agree that understanding the bustling signaling networks that mitochondria establish within and between cells could help unlock secrets about health and disease. “If we understand how the mitochondria are acting together, and we learn how to manipulate it,” said James Eberwine, a molecular neurobiologist at the University of Pennsylvania, “we’re going to gain so much more insight into biology.”
Read the whole story in Quanta Magazine
Image: Abu Shawka, Wikimedia Commons
New research suggests that early modern humans used fire to transform a dense, closed-canopy “Afromontane” forest (depicted above) into a bushy, open-canopy “miombo” woodland around northern Lake Malawi in Africa.
Humanity’s environmental impact did not start with the bang of agriculture or industrialization but a whisper initiated long ago—one that scientists are finally learning to hear.
New archaeological and paleoenvironmental findings now date human activity that transformed our natural surroundings to more than 80,000 years ago, after early modern humans settled on the northern shores of Lake Malawi at the lower tip of eastern Africa’s Great Rift Valley. These humans dramatically modified the landscape and ecosystem by burning forests to yield a sprawling bushland that remains today, according to a report published on May 5th 2021 in Science Advances.
The finding marks the oldest evidence yet of humans profoundly changing their environment with fire. And it could represent the earliest known case of people deliberately doing so, the researchers hypothesize.
Read the whole story in Scientific American