Latest news with #Oligocene
Yahoo
7 days ago
- Business
- Yahoo
Scientists Studying Earth's Trees Issued a Stark Warning to Humanity
From towering coastal redwoods to dinosaur-era Wollemi pines and firs that make the perfect Christmas trees, even our most revered woody plants are in grave danger. But the loss of these species isn't just a blow to local forests – it threatens entire ecosystems, research shows. In 2021, the State of the World's Trees report revealed a startling finding: one-third of all tree species are on the brink of extinction, totaling around 17,500 endangered tree species. This is more than double the number of all threatened mammals, birds, amphibians, and reptiles combined. Some tree species are so rare that only a single known individual remains, such as the solitary palm, Hyophorbe amaricaulis, in Mauritius. In a subsequent study from 2022, the same researchers issued a "warning to humanity" about the far-reaching consequences of losing these trees, backed by 45 other scientists from 20 different countries. Conservation biologist Malin Rivers from Botanic Gardens Conservation International and colleagues outline the many impacts these losses will have on our economies, livelihoods, and food. Most of our fruit comes from trees, as do many nuts and medicines, with non-timber products amounting to about US$88 billion worth of trade. In the developing world, 880 million people rely on firewood for fuel, and 1.6 billion people live within 5 kilometers (3 miles) of a forest, relying on them for food and income. All up, trees contribute about US$1.3 trillion annually to the global economy, yet we're destroying billions of them every year – clearing massive tracts of land for farming and development. Trees are each their own little worlds, teeming with all sorts of single- and multicellular-life forms, including other plants, fungi, bacteria, and animals. Lose a tree, and this entire world dies too. They often form the supportive base for the whole web of life around them. In fact, half of all the world's animals and plants rely on treed habitats. "Habitat loss is frequently tree loss, it is at the root of that when we look at extinction concerns for animals or birds," Rivers told Nature World News in 2022. "There is no way we can take care of all the other creatures there if we don't take care of the trees." As with all living systems, losing diversity makes the whole jumble of living connections more vulnerable. This is because less variation means less diversity in immune response, in genes, and responses to environmental conditions, meaning lower chances of surviving the many threats battering the complex web of interactions that is life on Earth. Some tree species provide unique interactions and can't be replaced by other species. This includes the distinctive dragonsblood trees (Dracaena cinnabari), leftover from the ancient Oligocene woodlands, which are host to many other species that are entirely dependent on them, including many other plants and the gecko that pollinates them. So the extinction of a single species can cause a massive domino effect across everything else that interacts with it, even if they're already rare. Species that rely on our dwindling forests have already declined by around 53 percent since 1970, and more forests around the world are showing signs of increasing stress. This doesn't just impact the other life trees interact with either. Trees are interwoven with Earth's soil, atmosphere, and weather, too – cleaning our air, producing oxygen, and making it rain. They store three-quarters of the world's accessible freshwater and more than half its problematic carbon dioxide. Lose enough trees and our planet's cycling of carbon, water, and nutrients will be thrown into disarray. "We're showing that diverse forests store more carbon than monocultures," Rivers told The Guardian. "That's true for many ecological functions, not just carbon capture, but providing habitat to animals, soil stabilization, resilience to pests and diseases, resilience to storms and adverse weather. By losing tree diversity, we'll also lose diversity in all organisms: birds, animals, fungi, microorganisms, insects." A few tree species are getting lucky and are able to take advantage of the rapid environmental changes we've caused, like those creeping into territory that fires have cleared. But many more are being obliterated by the same processes. Much needs to be done to combat this at a collective level, but we all can play a part by recognizing the importance of trees and fighting our own plant blindness. In 2022, researchers pointed out that fewer people than ever are taking up botanical education in the UK at a time when we need plants more than ever. We must all think of the trees. The research was published in Plants, People, Planet. An earlier version of this article was published in September 2022. Dramatic Collapse of Swiss Glacier a Chilling Warning, Experts Say South Africa Is Rising Up Out of The Ocean, Scientists Reveal An Extreme Drop in Oxygen Will Eventually Suffocate Most Life on Earth
IOL News
15-05-2025
- Science
- IOL News
Rock solid friendships for UKZN geology graduates
A SHARED passion for geology has become the bedrock of a lasting friendship between UKZN students, Tamera Heeralal and Marinja Bester. This week their shared journey of late night studying, hot chocolate and challenging offshore work culminated in a well-deserved milestone; both graduated with Master's degrees in Geology from the University of KwaZulu-Natal. But it's also the beginning of a new chapter, as the two friends now take separate paths in the world of work. Tamera Heeralal, told the Independent on Saturday that her dad played a key role in her love for geology, especially marine geology. 'He always had National Geographic documentaries on, and I was especially fascinated by the ones about the ocean and seismologists tracking seismic activity. I remember turning to him and saying, 'I want to be just like them.'' She was drawn to the power and mystery of the earth, especially those unfolding beneath the surface; while her fascination with ocean research has been a driving force throughout her career. 'We've mapped the moon in more detail than our own oceans, which I found truly intriguing,' she said. Her thesis focused on submerged shorelines offshore Hottentots Bay, Namibia where she investigated the geomorphology and seismic stratigraphy of the area. 'Using pseudo-3D seismic profiles, multibeam bathymetry, backscatter data, and analysing over 6,400 drill cores, I aimed to better understand the evolution of the coastal shelf. The key findings of my research included the identification of paleo-surfaces and gravel beach formations, which indicated ancient sea level stands. I was able to reconstruct sedimentary sequences that correlate with sea level fluctuations spanning from the late Oligocene to the Holocene.' The outcome provided insights into the marine 'transgressions and regressions' which shaped the shoreline through various geological periods. Her work also sheds light on the dynamic processes that have influenced coastal evolution and offers a clearer understanding of past environmental changes in the region. 'This research is significant because it provides insights into how coastlines responded to past sea-level changes — a topic that is increasingly relevant in the context of rising sea levels due to global warming. By understanding how shorelines were preserved or eroded in the past, we can better predict how they might behave in the future.' When she's not collecting lava samples from an active volcano or monitoring earthquakes on land, Heeralal continues her exploration of the ocean floor by mapping it with high-resolution multibeam echosounders and collecting seismic data to reveal what lies beneath the seabed. 'It's not exactly how I imagined it as a child, but it's no less exciting. I get to contribute to our understanding of the seafloor in a way that respects and preserves the biodiversity of our oceans.' She speaks fondly of her friend Marinja saying that over the past eight years they've become family and the bond was cemented when they relocated to Cape Town to work for the same company. 'With no family around, our bond grew even stronger. We spent most of our time working offshore together, sharing everything from seasickness to laughter, our love for K-pop, and even quiet moments of reflection. After the madness of our master's journeys, we now get to graduate together, a full-circle moment I'll always cherish,' Heeralal says. Marinja Bester agrees that their friendship is as solid as a rock. She credits the many sleepovers and late-night cups of hot chocolate for giving them the courage to finish their research. 'We worked on the same survey ship, on the same team, shared a cabin, shared our seasickness debacles, the rough weather, the beautiful wildlife sceneries, shared many sunsets and sunrises and the best of all was sharing meals and secret midnight snacks onboard.' Bester always had a 'knack for geology' and as a child she would collect rocks while hiking with her family. Years later she learned that her parents secretly tossed some of them out when her backpack became too heavy. 'My natural love for the earth and the ocean and the inner workings and formation of it was a long-standing interest of mine. Putting together my love for rocks and the ocean, studying marine geology seemed like the natural way to go for me,' she said. Her thesis focused on data collected along the southern Namibian coastline just north of the Orange River mouth. The coastline, says Bester, is unique due to the formation of beach barriers and spit structures that have been preserved at water depths ranging between 55 m and 100 m below sea level. 'The analysis is primarily configured using remote sensing approaches, alongside drilled core samples to ground truth the seismic stratigraphy and provide age constraints. In the seismic stratigraphy data captured of this area, where the cross-section of the units below the seafloor can be seen, the units show movements of units growing towards the shore or outward to sea patterns are observed by their internal structures which were individually marked.' Bester says studying these depositional patterns reveal the historical coastline behaviour and sea-level fluctuations and allows scientists to correlate this with known events that have been documented in previous research. 'This way we can create a comprehensive geological model of the coastline under specific controls such as sea-level changes, sediment supply and underlying bedrock control. In these particular conditions we observe the formation of prograded barrier spits, downstepping barriers and mixed sand-gravel shorefaces. This also leads to the conclusion of the significant role geological controls play in barrier system development and preservation. Essentially, these preserved barrier spit formations act as a natural record book.' Studying geology changed the way Bester views the concept of time. 'Observing the earth and ocean gives me a moment to slow down and take a deep breath and remember that life doesn't have to be a rush going a million miles a minute. These beautiful creations and structures were formed over millions of years. This allows me to 'stop and smell the roses'.'
Forbes
04-05-2025
- Science
- Forbes
The Tooth Of The Matter: How Sharks Lost Half Their Ecological Roles
Analyzing over 9,000 fossil shark teeth reveals that today's sharks occupy less ecological space ... More than their ancient counterparts. (Maggie Martorell/Miami Herald/Tribune News Service via Getty Images) Sharks are one of the ocean's oldest survivors, with a fossil record stretching back at least 250 million years. But their story isn't just merely about survival… it's about transformation. A global study by scientists Dr. Jack A. Cooper and Dr. Catalina Pimiento, analyzing more than 9,000 fossilized shark teeth from 537 species across the Cenozoic era (i.e. the last 66 million years), has shed light on how shark diversity, particularly in terms of function, has changed over time — and what that means for our oceans today. Instead of focusing on just species numbers, the duo turned to shark teeth to understand functional diversity, or the variety of ecological roles sharks have played, based on differences in size, feeding strategy and tooth shape. By examining six specific dental traits known to link closely with function, the two researchers mapped out how shark ecosystems evolved, and shrank, throughout deep time. The teeth came from museums around the world and all the scientific literature they could get their hands on, spanning a global range and capturing an evolutionary story told in enamel. For about 60 million years, from the Paleocene through the Miocene (roughly 66 to 10 million years ago), sharks thrived in a wide variety of ecological niches. During this time, 66% to 87% of the potential ecological 'functional space' was occupied. That means sharks weren't just numerous — they were doing lots of different things. Some were small suction feeders, others were massive predators, and many filled in-between roles that helped balance marine food webs. Notably, this period featured high levels of functional redundancy, where multiple species performed similar roles. That kind of overlap isn't wasteful. Think of it like a buffer against extinction: if one species disappears, another can step in to keep the ecosystem running. But this balance took a major hit about 30 million years ago during the Oligocene. Functional redundancy dropped by about 45%, making the ecosystem more fragile. The loss of overlap meant that each remaining species held a more unique, irreplaceable role. This left the whole system more vulnerable, and the trend didn't improve. From the late Miocene onward, about 10 million years ago, shark functional diversity began a steady decline. Today, sharks have lost 44% of the functional richness they once had. Many of the roles once filled by mid-sized suction feeders and large-bodied predators are simply… gone. What's striking is that extinct sharks were doing more than their modern relatives in terms of ecological variety. They spanned a broader range of functional roles than the sharks we see in today's oceans. The loss of those species — and their roles — means our current shark populations are not only smaller in number, but also less functionally diverse. This matters, Cooper and Pimiento explain, because functional diversity is closely tied to ecosystem health. The fewer roles sharks fill, the less resilient our oceans become. For about 60 million years, from the Paleocene through the Miocene (roughly 66 to 10 million years ... More ago), sharks thrived in a wide variety of ecological niches. During this time, 66% to 87% of the potential ecological 'functional space' was occupied. That means sharks weren't just numerous — they were doing lots of different things. Some, like Haimirichia amonensis, were small suction feeders likely adapted to snapping up soft-bodied prey like squid. Others, such as the massive Otodus megalodon, were apex predators capable of preying on large marine mammals. In between were species like Hemipristis serra, with serrated teeth suited for slicing through flesh, indicating a role as a powerful mid-sized predator. There were also bottom-dwellers like Galeorhinus cuvieri, which probably hunted crustaceans and small fish, and long-snouted filter-feeders like Pseudomegachasma, which may have filtered plankton from the water. Together, these species helped maintain a balance in the marine food web by occupying a broad spectrum of feeding strategies, sizes, and ecological roles. Importantly, this decline didn't happen overnight. It's (thankfully?) been unfolding for millions of years. But the pressure modern sharks face from overfishing, habitat destruction and climate change is piling on top of an already weakened system. It's like kicking a structure that's already crumbling at the foundation. What's left today is a thinner slice of the rich ecological tapestry that sharks once wove through the oceans. And if we continue to lose the few remaining threads, the consequences could ripple far beyond sharks themselves. Cooper and Pimiento hope their work acts as both a warning and a guide. By understanding how shark functional diversity has changed through time, scientists can better predict which roles are most at risk and which species are keystones worth prioritizing for conservation. Protecting the sharks of today isn't just about saving individual species, they argue, but about preserving the roles they play and the balance they bring to marine ecosystems. Sharks have weathered mass extinctions, sea-level shifts and global climate swings. But their long history on our blue marble planet also shows us that their current decline isn't part of a natural cycle, but a breaking point. The oceans of the past were richer, not just in life but in function. If we want to keep the ocean ecosystems we rely on, we'll need to make sure sharks can keep doing the jobs they've done for millions of years.
