from the world's big
Scientists think an insect similar to the modern millipede crawled around Scotland 425 million years ago, making it the first-ever land-dweller.
- An ancient millipede-like creature living in Scotland may have been the first creature to live on land.
- A fossil representing Kampecaris obanensis was first discovered in 1899 on the Scottish isle of Kerrera. It's now been radiometrically dated to 425 million years ago.
- If the new research is correct about the age of the fossil, then scientists have been greatly underestimating how rapidly bugs and plants evolved to transition to life on land.
A pioneering insect<p>One idea about how life began on Earth theorizes that it began in bodies of water. The cocktail of gases in the atmosphere mixed with lightning strikes is thought to have allowed monomers such as amino acids to spontaneously form in the oceans. This is known as the "primordial soup" theory. Out of this life-creating stew, bugs known as <a href="https://www.britannica.com/animal/arthropod" target="_blank">arthropods</a> (which includes insects, spiders, crustaceans, and centipedes) are thought to have been some of the very first animals to venture onto land. </p><p>There's indirect soil-based evidence that other insects like soil worms crawled on land before the myriapods. However, the evidence may only indicate fleeting trips to the land above water. Myriapods, we know, made land their permanent home. The fossil of the ancient millipede-like creature, <a href="https://en.wikipedia.org/wiki/Kampecaris" target="_blank"><em>Kampecaris</em></a><em> obanensis</em>, <a href="http://fossilworks.org/bridge.pl?a=taxonInfo&taxon_no=374000" target="_blank">was first discovered</a> in 1899 on the Scottish isle of Kerrera. Now, it's been radiometrically dated to 425 million years ago. That would make these multi-legged critters the oldest land animal ever to have lived out of water. (At least, that we know of.) Their pioneering journey out of the sea set forth an explosive multiplication of new terrestrial life forms. Just 20 million years after <em>Kampecaris</em> made the move to land, the fossil record shows a plethora of bug deposits. Fast-forward another 20 million years and there is evidence that spiders, insects, and tall trees were thriving in ancient forest communities. </p><p>"It's a big jump from these tiny guys to very complex forest communities, and in the scheme of things, it didn't take that long," <a href="https://news.utexas.edu/2020/05/27/worlds-oldest-bug-is-fossil-millipede-from-scotland/" target="_blank">said geoscientist Michael Brookfield</a> from the University of Texas and the University of Massachusetts in Boston, in a press release. "It seems to be a rapid radiation of evolution from these mountain valleys, down to the lowlands, and then worldwide after that."</p>
Remaining questions<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="12ce877e7e1d97ea8cb8294a8f73bad5"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/SjNQUOYtZC0?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p>We can't be sure that <a href="https://en.wikipedia.org/wiki/Kampecaris" target="_blank"><em>Kampecaris</em></a> is actually the very first creature to have lived on land, as it's possible that there are older undiscovered fossils of both plants and bugs. However, no earlier findings have been made despite the fact that researchers have been investigating some of the most well-preserved fossils from this era. The team thinks this may indicate that they have reached the end of the land fossil record and that this ancient millipede represents the vital turning point at which life moved onto land.</p><p>According to this new study, <em>Kampecaris</em> is about 75 million years younger than the age other scientists have estimated the oldest millipede to be using a technique known as molecular clock dating, which is based on DNA's mutation rate. Similarly, fossils of stemmed plants in Scotland have also been evaluated as being roughly 75 million years younger than researchers once thought. So, if this ancient critter really was the first bug to blaze the trail onto Earth, then scientists have been greatly underestimating how rapidly bugs and plants evolved to transition to life on land. </p><p>"Who is right, us or them?" study co-author Elizabeth <a href="https://news.utexas.edu/2020/05/27/worlds-oldest-bug-is-fossil-millipede-from-scotland/" target="_blank">Catlos said</a>. "We're setting up testable hypotheses – and this is where we are at in the research right now."</p>
Mastering zircons<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzM4MzI2Ni9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTYzNjUxMzQzOH0.pnxG9fxIx8eMJxbj18j4sMkZerjoniCAvmMVQazkemc/img.png?width=980" id="7f6ec" class="rm-shortcode" data-rm-shortcode-id="37946233816f7957836612f030d92ace" data-rm-shortcode-name="rebelmouse-image" alt="modern millepede" />
Javier Fernández Sánchez / Getty Images<p>Despite the potentially huge evolutionary significance of <em>Kampecaris</em>, this was the first study to address the fossil's age. One reason for that could be the challenge of extracting zircons (a microscopic mineral necessary to accurately date fossils) from the ashy rock sediment in which the fossil was preserved. Extraction requires impeccable vision and a flawlessly steady hand, as the zircons can easily be flushed away by accident. There's almost no room to err.</p><p>One of the co-authors of the study, geoscientist Stephanie Suarez, has been mastering the technique for separating the zircon grain from sediment since her time as an undergraduate student. </p><p>"That kind of work trained me for the work that I do here in Houston," Suarez said. "It's delicate work."</p><p>As an undergrad, Suarez used the technique to find that a different millipede specimen that was once thought to be the oldest bug specimen was <a href="https://www.jsg.utexas.edu/news/2017/07/ancient-animal-thought-to-be-first-air-breather-on-land-loses-claim-to-fame/" target="_blank">actually 14 million years younger</a> than estimated. Her technique now passes the Oldest Bug To Walk The Earth title onto a new species; <em>Kampecaris</em>.</p>The study was published in <a href="https://www.tandfonline.com/doi/full/10.1080/08912963.2020.1761351" target="_blank" style="">Historical Biology</a>.
New research establishes an unexpected connection.
- A study provides further confirmation that a prolonged lack of sleep can result in early mortality.
- Surprisingly, the direct cause seems to be a buildup of Reactive Oxygen Species in the gut produced by sleeplessness.
- When the buildup is neutralized, a normal lifespan is restored.
We don't have to tell you what it feels like when you don't get enough sleep. A night or two of that can be miserable; long-term sleeplessness is out-and-out debilitating. Though we know from personal experience that we need sleep — our cognitive, metabolic, cardiovascular, and immune functioning depend on it — a lack of it does more than just make you feel like you want to die. It can actually kill you, according to study of rats published in 1989. But why?
A new study answers that question, and in an unexpected way. It appears that the sleeplessness/death connection has nothing to do with the brain or nervous system as many have assumed — it happens in your gut. Equally amazing, the study's authors were able to reverse the ill effects with antioxidants.
The study, from researchers at Harvard Medical School (HMS), is published in the journal Cell.
An unexpected culprit
The new research examines the mechanisms at play in sleep-deprived fruit flies and in mice — long-term sleep-deprivation experiments with humans are considered ethically iffy.
What the scientists found is that death from sleep deprivation is always preceded by a buildup of Reactive Oxygen Species (ROS) in the gut. These are not, as their name implies, living organisms. ROS are reactive molecules that are part of the immune system's response to invading microbes, and recent research suggests they're paradoxically key players in normal cell signal transduction and cell cycling as well. However, having an excess of ROS leads to oxidative stress, which is linked to "macromolecular damage and is implicated in various disease states such as atherosclerosis, diabetes, cancer, neurodegeneration, and aging." To prevent this, cellular defenses typically maintain a balance between ROS production and removal.
"We took an unbiased approach and searched throughout the body for indicators of damage from sleep deprivation," says senior study author Dragana Rogulja, admitting, "We were surprised to find it was the gut that plays a key role in causing death." The accumulation occurred in both sleep-deprived fruit flies and mice.
"Even more surprising," Rogulja recalls, "we found that premature death could be prevented. Each morning, we would all gather around to look at the flies, with disbelief to be honest. What we saw is that every time we could neutralize ROS in the gut, we could rescue the flies." Fruit flies given any of 11 antioxidant compounds — including melatonin, lipoic acid and NAD — that neutralize ROS buildups remained active and lived a normal length of time in spite of sleep deprivation. (The researchers note that these antioxidants did not extend the lifespans of non-sleep deprived control subjects.)
Image source: Tomasz Klejdysz/Shutterstock/Big Think
The study's tests were managed by co-first authors Alexandra Vaccaro and Yosef Kaplan Dor, both research fellows at HMS.
You may wonder how you compel a fruit fly to sleep, or for that matter, how you keep one awake. The researchers ascertained that fruit flies doze off in response to being shaken, and thus were the control subjects induced to snooze in their individual, warmed tubes. Each subject occupied its own 29 °C (84F) tube.
For their sleepless cohort, fruit flies were genetically manipulated to express a heat-sensitive protein in specific neurons. These neurons are known to suppress sleep, and did so — the fruit flies' activity levels, or lack thereof, were tracked using infrared beams.
Starting at Day 10 of sleep deprivation, fruit flies began dying, with all of them dead by Day 20. Control flies lived up to 40 days.
The scientists sought out markers that would indicate cell damage in their sleepless subjects. They saw no difference in brain tissue and elsewhere between the well-rested and sleep-deprived fruit flies, with the exception of one fruit fly.
However, in the guts of sleep-deprived fruit flies was a massive accumulation of ROS, which peaked around Day 10. Says Vaccaro, "We found that sleep-deprived flies were dying at the same pace, every time, and when we looked at markers of cell damage and death, the one tissue that really stood out was the gut." She adds, "I remember when we did the first experiment, you could immediately tell under the microscope that there was a striking difference. That almost never happens in lab research."
The experiments were repeated with mice who were gently kept awake for five days. Again, ROS built up over time in their small and large intestines but nowhere else.
As noted above, the administering of antioxidants alleviated the effect of the ROS buildup. In addition, flies that were modified to overproduce gut antioxidant enzymes were found to be immune to the damaging effects of sleep deprivation.
The research leaves some important questions unanswered. Says Kaplan Dor, "We still don't know why sleep loss causes ROS accumulation in the gut, and why this is lethal." He hypothesizes, "Sleep deprivation could directly affect the gut, but the trigger may also originate in the brain. Similarly, death could be due to damage in the gut or because high levels of ROS have systemic effects, or some combination of these."
The HMS researchers are now investigating the chemical pathways by which sleep-deprivation triggers the ROS buildup, and the means by which the ROS wreak cell havoc.
"We need to understand the biology of how sleep deprivation damages the body so that we can find ways to prevent this harm," says Rogulja.
Referring to the value of this study to humans, she notes,"So many of us are chronically sleep deprived. Even if we know staying up late every night is bad, we still do it. We believe we've identified a central issue that, when eliminated, allows for survival without sleep, at least in fruit flies."
Atop certain glaciers are herds of small mossy balls that somehow move together when no one's looking.
- Weird but cute, "glacier mice" are actually balls of moss, dirt, and more.
- The balls move, oddly, in packs through some unknown means.
- A new study tracked 30 glacier mice but still couldn't figure out what's going on.
Scientists have known about them at least since the 1950s, when Jón Eythórsson named them "jökla-mýs," which translates as "glacier mice." However, they're not actually mice. They're smallish balls of moss, and there are lots of them atop Alaska's Root Glacier. They can also be found on ice in Iceland, Svablard, and even South America, presumably places with just the right conditions, though researchers don't know what those conditions are.
The really odd thing about them is that they apparently move in some unexplained way, though no one has observed them doing so. It's just that repeated visits find them in different places.
And that's not the coolest part. "The whole colony of moss balls, this whole grouping, moves at about the same speeds and in the same directions," geologist Tim Bartholomaus of University of Idaho (UI) tells NPR. "Those speeds and directions can change over the course of weeks."
Bartholomaus and two colleagues have published their research on glacier mice in Polar Biology.
Mice but not mice
Image source: Steve Coulson/ The University Center at Svalbard
The "glacier mice" nickname has stuck perhaps because glaciologists are so fond of the fuzzy things. They are pillow-like, soft, squeezable objects, comprised of different species of moss, but that is not all.
A 2012 study found entire thriving habitats inside the mice. "I had expected to find some animals, but not so many," said study author and arctic biologist Steve Coulsonto to the New York Times. His research revealed springtails (six-legged insects), tardigrades (of course), and simple nematode worms. In a single mouse, there were 73 springtails, 200 tardigrades, and 1,000 nematodes.
Co-author of the new study, wildlife biologist Sophie Gilbert of UI describes them:
"They really do look like little mammals, little mice or chipmunks or rats or something running around on the glacier, although they run in obviously very slow motion."
Clues and an unsolved mystery
Some glacier mice are found perched on ice pedestals.
Image source: Fanny Dommanget/The University Center at Svalbard
Her report recounts the efforts made by Bartholomaus and his co-authors, which also included biologist Scott Hotaling of Washington State University, to figure out how the mice are getting around.
The 2012 study outfitted some mice with accelerometers and confirmed that they do rotate, but that's as far as its authors went into the balls' means of travel.
For Bartholomaus and his cohorts, there were some clues going into this.
For example, occasionally, balls are found perched on a pedestal of ice as seen above, perhaps shading that spot from melting sunlight until it finally melts and the ball rolls away.
Another clue is the intact nature of the healthy moss that serves as each ball's surface — it's a sign that they all have their turn in the sun. "These things must actually roll around or else that moss on the bottom would die," says Gilbert.
One obvious explanation was quickly ruled out — they're not simply rolling downhill, because many of them were found to be on level surfaces.
For the study, the researchers tagged 30 of the mice with a loop of wire and colored beads that identified each ball. They tracked their position for 54 days in 2009, and again in 2010, 2011, and 2012.
Bartholomaus explains, "By coming back year after year, we could figure out that these individual moss balls were living at least, you know, five, six years and potentially much, much longer."
Although the researchers expect the movements of the balls would be individualized and random, that's not what they found. The balls moved about an inch a day, and together, like a herd of animals.
Also, they periodically changed direction. "When we visited them all, they were all just sort of moving relatively slowly and initially toward the south," Bartholomaus said. "Then they all started to speed up and kind of start to deviate toward the west. And then they slowed down again and progressed even farther to the west."
Wind, maybe? Measurements of the dominant winds in the area ruled that out. Sunlight patterns also failed to account for the movement of the packs.
So, what's going on? Admits Barholomaus, "We still don't know. I'm still kind of baffled."
Given scientists' affection for the little balls, other people are also rolling the idea around in their minds. Ruth Mottram of the Danish Meteorological Institute suggests to NPR, "I think that probably the explanation is somewhere in the physics of the energy and the heat around the surface of the glacier, but we haven't quite got there yet."
Another theory put forward is that the moss on a ball's underside grows and pushes it over and forward, cueing up the next moss to begin growing in the same way. If growth rates from ball to ball are similar, this could explain their herd-like movement.
The mystery is reminiscent of the "sailing stones" of Death Valley that perplexed scientists for years unit their secret was revealed: They're pushed around by the wind as they temporarily float on wet melting ground ice.
Each pile of dung contains a cornucopia of seeds, perfect for reforesting.
- Tapirs produce towering piles of feces full of large-tree seeds other animal can't pass.
- Stashing tasty fecal morsels for later, dung beetles bury the seeds.
- Tapirs prefer burned-out areas, making them ideal re-foresters.
The Amazon rainforest has been in trouble for some time. In the last 40 years, more than 18% of Brazil's rainforest, for example, has been decimated by logging, farming, mining, and cattle ranching. That's an area about the size of California. If it isn't deliberate deforestation for commercial purposes, it's fires. Last years's unprecedented rainforest conflagrations, 85% more severe than the previous year's, were absolutely devastating, burning away some 10.123 square kilometers of forest. This year looks worse — in the first four months of 2020 alone, 1,202 square kilometers have been incinerated.
Often poking their way though the charred remains are trunk-nosed lowland tapirs (Tapirus terrestris), and that's a great thing. "Tapirs in Brazil are known as the gardeners of the forests," says ecologist Lucas Paolucci of Amazon Environmental Research Institute in Brazil. They're prodigious defecators whose feces is packed with a remarkable assortment of seeds from the plants they ingest. Paolucci has great hopes for the role that tapirs, along with dung beetles, their partners in grime, can play in reforesting the Amazon. It's something they're already doing on their own.
Tapir poop in a zoo
Image source: Kulmalukko/Wikimedia
The tapir is South America's largest native mammal, looking a bit like a pig with a trunk. It's actually more closely related to a horse or rhinoceros, and is believed to have been around for tens of millions of years.
Paolucci found tapir's massive mounds of dung — "bigger than my head" — hard to miss. Inside each pile is a treasure trove of seeds including those from large, carbon-storing trees that are just too big to pass through the digestive tracts of smaller mammals. This makes them invaluable disseminators of exactly the sort of trees needed to rebuild a forest.
Tapirs seem to prefer the burned-out areas in which they're most needed, too. In 2016, Paolucci joined other researchers in studying the type of areas tapirs like to frequent. In eastern Mato Grasso, they tracked the goings-on in three plots of forest land. Two of these plots had been subjected to controlled burns from 2004 to 2010. One of then was burned every year, while the other was torched every three. The third plot was left unburned as a control.
Patrolling the plots, the researchers recorded the locations of 163 tapir-dung piles, confirming their source with camera-trap recordings of the perpetrators. The tapirs, it turned out, spend much more time in the burned out forest plots than the untouched one. Paolluccis suggests they may prefer the warm sunshine in areas not covered by forest canopy.
When the researchers extracted and counted up the seeds in those piles, an impressive array was cataloged: 129,204 seeds representing 24 plant species. Biodiversity writ in poo.
Image source: Jasper_Lensselink_Photography/Shutterstock
Seeing the tapirs' deposits leading to widespread new growth meant that something, or someone, else, had been spreading them out for planting: Dung beetles, of the superfamily Scarabaeoidea. Paolucci conducted an experiment that confirmed that dung beetles break off piles of tapir dung, roll them away, and bury them for later munching. The seeds in their snacks are in effect planted where they can grow.
Early last year, Paolucci retrieved 20 kilograms of tapir poop from the Amazon, breaking it apart into 700-gram clumps. He returned these clumps to the Amazon after stuffing each one with plastic pellets to serve as as dummy seeds. After 24 hours, Paolucci collected the clumps and counted the pellets gone missing, a simple way to calculate the number of new plants the dung beetles had planted that day. He hopes to publish the details of his study next year.
While tapirs and their dung-beetle buddies clearly can help reforest the Amazon, they, like everything else trying to live in the rainforest region, are themselves endangered by the raging forest fires. If they're lost, going with them will be a fantastic means of spreading large-tree seeds through the region.
Entomologist William Romoser of Ohio University says NASA images depict insect- and reptile-like creatures on Mars.
- Entomologist William Romoser gave a presentation this week in which he claimed NASA photos show evidence of creatures, some still living, on the red planet.
- Romoser has worked as a professor of entomology at Ohio University for four decades.
- It's likely that the real phenomenon in Romoser's work is pareidolia — the tendency to "see" recognizable shapes among random visual data.
(NASA/JPL; William Romoser/Ohio University)<p>"Once a clear image of a given form was identified and described, it was useful in facilitating recognition of other less clear, but none-the-less valid, images of the same basic form," Romoser <a href="https://www.sciencealert.com/an-entomologist-is-trying-to-convince-us-that-mars-is-covered-in-bugs" target="_blank">said</a>.</p><p>To analyze the photos, Romoser played with factors like saturation, brightness and contrast, but he didn't add or remove any content from the photos, according to a <a href="https://www.ohio.edu/news/2019/11/ohio-entomologist-photos-show-evidence-life-mars" target="_blank">press release</a> from Ohio University.</p>
(NASA/JPL; William Romoser/Ohio University)<p>"An exoskeleton and jointed appendages are sufficient to establish identification as an arthropod. Three body regions, a single pair of antennae, and six legs are traditionally sufficient to establish identification as 'insect' on Earth. These characteristics should likewise be valid to identify an organism on Mars as insect-like. On these bases, arthropodan, insect-like forms can be seen in the Mars rover photos."<br></p>
(NASA/JPL; William Romoser/Ohio University)<p>Romoser said some of the creatures he saw in the images resemble carpenter bees and snakes. It's a bold (and probably false) claim. It's also not the first time Romoser has reported "evidence" of life on Mars. </p><p>In 2017 and 2018, he published <a href="https://www.researchgate.net/profile/William_Romoser2" target="_blank">two reports</a> describing "unidentified aerial phenomena" on the red planet. As Amanda Kooser wrote for <em><a href="https://www.cnet.com/news/scientist-claims-to-spot-insects-on-mars-but-i-think-theyre-just-rocks/" target="_blank">CNET</a></em>, the more likely phenomenon driving Romoser's findings is pareidolia, which is our tendency to "see" recognizable shapes in just about anything, from <a href="https://www.telegraph.co.uk/news/newstopics/howaboutthat/10790063/Jesus-Christs-face-shows-up-in-a-California-pancake.html" target="_blank">pancakes</a>, to the <a href="https://www.google.com/search?q=woman+sees+jesus+in&rlz=1C5CHFA_enUS871US871&oq=woman+sees+jesus+in+&aqs=chrome..69i57.5312j0j7&sourceid=chrome&ie=UTF-8" target="_blank">flames of the Notre Dame fire</a>, to photos from the Mars rovers.</p><p>Back on Earth, Romoser has spent 45 years as an entomology professor at Ohio University, where he co-founded the Tropical Disease Institute. He also worked as a researcher for the U.S. Army Medical Research Institute of Infectious Diseases, and has authored and co-authored four editions of the widely-used textbook, "<em>The Science of Entomology</em>."</p>
(NASA/JPL; William Romoser/Ohio University)<p>At the very least, Romoser said this week, his findings suggest scientists should keep looking for life on Mars.</p><p>"The evidence of life on Mars presented here provides a strong basis for many additional important biological as well as social and political questions," he added. "It also represents a solid justification for further study."</p><p>Next year, the <a href="https://www.cnet.com/news/nasa-will-hunt-for-fossils-on-mars/" target="_blank">Mars 2020 rover</a> plans to do just that, only its main focus will be searching for past microbial life.</p>