Lab Notes

Electric catfish are the Nile River's most wonderous fauna. The fish’s ability to generate high-voltage electric fields fascinated ancient Egyptians, who featured the fish prominently in their art and used them to treat chronic pain.

Advances in the human understanding of electricity helped eighteenth century scientists to explain the nature of an electric catfish’s shocks and to identify the specialized electric organs that produce them. More recent advances in genomics have helped elucidate the genetic basis and evolutionary history of those amazing organs. Still, despite our millennia of familiarity and centuries of modern scientific study, there’s plenty left to learn about the electric catfish. In particular, are the fish immune to their own shocks?

Georg Welzel and Stefan Schuster from the University of Bayreuth in Germany recently published a study aimed at that very question. They compared the responses of electric catfish and goldfish to different electrical stimuli, observing the movements of the fish after exposure to electrical discharges from both another electric catfish and electrofishing electrodes. While the goldfish were greatly affected by electric shocks from electric catfish and completely immobilized by the electrodes, the electric catfish appeared to be completely unfazed by any shocks. 

Although this study showed that electric catfish are immune to their own shocks, exactly how they achieve that immunity remains unclear. The fish did not physically respond, so their bodies may be insulated against or tolerant to electricity. Regardless of which mechanism they use, these catfish have yet to lose their mystery or magic.

Looming more than four kilometers above sea level, the Tibetan plateau is both the largest and highest plateau on Earth. Home to two of the world’s tallest peaks, Everest and K2, the “Roof of the World” owes its literally breath-taking topography to the geological equivalent of a car crash between the Indian and Eurasian plates — a collision that continues to this day, causing earthquakes and occasionally forcing a revision of Mt. Everest’s official altitude. 

But while scientists mostly agree on the broad strokes of Tibet’s chaotic formation, the details — specifically whether or not the plateau grew taller after its initial formation — have remained something of a geologic riddle. 

Reconstructions of plate movements and stratigraphic evidence suggest that it did, potentially shooting up abruptly between 20 and 10 million years ago and rising a bit more gradually after that. But when scientists used the Tibetan fossil and isotope records to reconstruct the paleolatitude of the region, they found no evidence of elevation gain. Indeed, according to fossil evidence, Tibet might even have sunk by up to a kilometer

Now, University of Copenhagen geologist Giampiero Iaffaldano thinks he’s found a way to reconcile the apparently conflicting evidence. 

To retrace the geologic past of the “Roof of the World,” Iaffaldano looked down to the ocean floor. Seafloor rock preserves snapshots of the Earth’s magnetic field captured at seafloor spreading centers — places where hot rock from the subsurface rises to become new seafloor. Those snapshots can be used to reconstruct the movement of the Earth’s crust in the distant past, and Iaffaldano used them to constrain India’s motion during Tibet’s formation. 

With a better idea of how plate motions unfolded over the last tens of millions of years, Iaffaldano was able to calculate how much force the Indian plate may have experienced as it rammed into Eurasia. By comparing his result to other scientists’ estimates of the amount of force needed for altitude increase, he determined that Tibet probably did rise — just not by very much. 

Critically, the modest altitude gain Iaffaldano suggests — just a few hundred meters — wouldn’t be enough for paleoaltimetry records to accurately resolve. If he’s right, both lines of apparently contradictory evidence for Tibet’s ancient altitude can be neatly accommodated into one unified story.

Earlier this year, Google released an artificial intelligence-based dermatology app called Derm Assist. Based off pictures alone, it is capable of recognizing 288 different skin conditions — with one big caveat: The app, developed out of a 2020 Google study published in Nature Medicine, was built on a 64,387-image database heavily biased toward images of white and light brown skin. 

In fact, only 3.5 percent of people in the images used to train the algorithm had Fitzpatrick skin types V and VI, which include brown, dark brown, and black skin. Most of the images in the database belonged to people with fair skin, darker white skin, or light brown skin, according to the study. 

So if you have dark or black skin, the app is likely to overdiagnose or underdiagnose your skin. This isn't surprising, based on Google's recent history. The company made news earlier this year by unceremoniously firing artificial intelligence ethics researchers Timnit Gebru and Margaret Mitchell. It's clear that Google doesn't want to put in actual effort into developing ethical apps and artificial intelligence. The company itself is only 3.7 percent Black, and just 1.6 percent of its employees are Black women, according to a 2020 diversity report.  

As much as we like to think that medicine and health are objective, they aren't. For example, people who are Black or Latinx were several times more likely to die of COVID-19 than white people, and  and Black people are less likely to be treated by a cardiologist while in an intensive care unit forgo heart failure than white people. Google continues to perpetuate these inequalities through their research applications.

Water filtration is an important step in drinking water infrastructure and wastewater treatment. But filters don't last forever — bacteria can attach to filtration membranes (structures that separate contaminants from water) and form biofilms in a process called biofouling. Biofouling reduces membrane lifetime and water quality. 

Water filtration membranes often have a mesh, called a spacer, that separates different layers of the membrane from each other. Bacteria can attach to this spacer. One way to reduce bacterial adhesion to the spacer is by making it water repellent, or superhydrophobic. In a study published in ACS Applied Bio Materials, scientists used candle soot to create superhydrophobic membrane spacers and keep biofouling cells away. 

Researchers from the Zuckerberg Institute for Water Research in Israel coated the filtration spacer with a chemical called polydimethylsiloxane. They then held the spacer over a candle flame until it was covered with particles of soot. To test the effectiveness of the spacer, the researchers treated them with two species of bacteria and one species of diatom. 

The common bacterium Pseudomonas aeruginosa, and the salt water species Cobetia marina and Navicula perminuta could not form biofilms on the soot covered spacers, unlike on uncoated spacers. These results demonstrate a simple way of creating biofouling-resistant membrane spacers cheaply using household candles. If this technique can translate to the water purification industry, superhydrophobic soot membranes could ead to less waste and lower filtration costs.  

Paper wasps (Polistes fuscatus) are very good at recognizing and remembering individual faces. In the spring, sexually mature females, known as “foundresses,” race to secure a nest site which they may maintain either alone or alongside a coterie of co-foundresses with whom they share brood space. For a given foundress to cooperate with her allies and thwart potential usurpers, she must be able to recognize individual wasps as distinct entities. 

The most thoroughly studied populations of paper wasps are those in and around Ann Arbor, Michigan and Ithaca, New York. Wasps from both locations show a striking amount of diversity in facial markings and possess the ability to learn and remember individual faces. Recently, a new population was discovered in Rothrock, Pennsylvania in which individuals seem to lack the highly variable face patterning present in the NY and MI populations. Is this observation an indication that this population lacks the ability to recognize individuals in the way that other populations do?

In their study, Elizabeth Tibbetts and her team of researchers from the University of Michigan found that the Pennsylvania population does exhibit far less variation in facial markings than the Michigan wasps. By measuring social interactions between familiar and unfamiliar social partners, they discovered no evidence that the Pennsylvania wasps remember other individuals. Furthermore, when subjected to a learning assay, the Pennsylvania population appeared to be incapable of learning to distinguish faces while the Michigan population learned to do so very quickly. They also demonstrated that Pennsylvania population was genetically distinct from the Michigan population, which they attributed to the geographic distance between them. 

It is unclear whether or not the Pennsylvania population has lost the high level of facial pattern variation and individual recognition that has made P. fuscatus famous, or failed to acquire it. What is clear, however, is that paper wasp communication systems are capable of rapid evolution and can vary even within a species. 

Every autumn, monarch butterflies migrate magnificently from northern America and Canada down to the Oyamel forests of Mexico. The butterflies congregate on Oyamel fir, or ‘sacred trees’, so densely that their collective weight can break off branches. Protecting Oyamel forests is critical to protecting monarchs.

However, protecting the Oyamel forest protection is complicated, as illustrated by a study recently published in the journal World Development. The study investigated the complex and dark network beneath the Monarch Butterfly Biosphere Reserve (MBBR) by conducting semi-structured interviews with locals, government workers, and NGO workers. It found that cartel members often log trees from monarch habitat, then work in concert with corrupt government officials, who authorize the conversion of the newly deforested land into avocado plantations. 

The study also highlighted a paradoxical and important concept in ecosystem conservation: that of socioecological frontiers, which are a novel system of human-environment interactions. The MBBR was established to protect Oyamel forest by making it a “people-free” zone, but this seemingly good intention has had negative impacts on local people. Their traditional ecological practices became prohibited, making the forest less healthy. Moreover, local people are caught in an oppressive web of market demands, government corruption, and cartel activity, which all dictate the use of a forest that was previously theirs to sustainably farm.

This study presents a nuanced look into the world of corruption in the MBBR. As an entity supported by UNESCO and the World Wildlife Federation, the reserve may seem innocuous and even admirable from the outside. However, even though it has good intentions, the MBBR may be allowing corrupt government and cartel members to work together to destroy monarch habitat, all whilst simultaneously marginalizing the Indigenous peoples within it.

What happens when a scientific paper is found to be fraudulent, plagiarized, or unreliable? After a potentially lengthy investigative process, the paper will be officially retracted and the journal will write a retraction notice to let readers know why the paper has been pulled. But retractions don’t make a paper disappear altogether. Retracted papers continue to get cited, spreading misinformation through the scientific literature.  

Now, a new study by a group of Stanford University researchers published in PLoS ONE suggests that the attention retracted papers receive from news sites and social media is problematic as well. They found that popular articles, defined as those with an Altmetric attention score of more than 20, “receive substantially more attention than their retraction notice.”  And it gets worse: The researchers found that the attention popular articles receive after they are retracted “does not always reflect their retraction, but may perpetuate” the flawed science they contain.

This suggests that journalists and social media users, as well as scientists, need to be wary of retracted papers. Fortunately, there are tools that can help with this. For scientists the reference manager Zotero will flag retracted papers and warn you before you cite them, and for journalists or members of the public who don’t use a reference manager, searching scite.ai for the title of the paper will let you know if it is problematic.  

Invasive mammalian predators threaten wildlife and even cause extinctions of their prey in many places around the globe. The impact of invasive mammalian predators on islands is especially strong, because many island species evolve in an environment free of predatory mammals, and lack antipredator behaviors. They become easy prey.

New Zealand is a good example of this; it is one of the countries with most bird extinctions due to  introduced mammalian predators such as rats and weasels. As such, the country is invested in predator control using innovative techniques. 

A new study conducted in New Zealand and published in Science Advances details how a group of researchers made use of the mammalian predators' keen senses of smell to fool them, by using "misinformation" in the form of fake prey scents. The experiment was designed to make predators (ferrets, cats and hedgehogs) less efficient at hunting using a paste made from the carcasses and feathers of quails, gulls, and chickens — three common bird species. The idea was to habituate the predators to smelling these birds without encountering them, thus tricking the predators into ignoring other bird smells as well.

The researchers exposed the predators to the smell of the paste for five weeks before native birds began to nest, then monitored their attacks on native bird nests for eight weeks after that. The experiment reduced the frequency of nest attacks and increased the number of eggs hatching 1.7-fold, at minimum doubling the odds of successful hatching during the experiment. Furthermore, using these numbers, the researchers modelled the potential population increases for native birds if the treatment was used for 25 years, and found that it could increase bird populations by 127 percent.

The experiment showed that using misinformation can affect predator behavior, making them lose interest in endangered species. Furthermore, the technique is cheaper than conventional lethal predator control methods such as trapping and poisoning. 

Hypoxia is a potentially deadly lack of oxygen and is especially lethal for brain cells. When there is not enough oxygen in the brain, extra hydrogen sulfide is produced, a gas commonly found in sewers and geysers and known for the odor of rotten eggs. As hydrogen sulfide accumulates in the brain, it stops neurons from producing energy, thereby killing them. 

To figure out how to treat hypoxia, a group of researchers wanted to understand how toxic levels of hydrogen sulfide are processed in the brain. First, they exposed a group of mice to the gas intermittently for several days in a row. After the initial exposure, the mice entered a hibernation-like state, in which they became immobile and their body temperatures dropped. However, their brains quickly adapted to the elevated levels of hydrogen sulfide and they were back to acting completely normal after breathing the gas on the fifth day. After that, the mice were able to tolerate severe hypoxia.

When studying the animals’ brains after this experiment, the researchers found elevated levels of a specific enzyme called sulfide: quinone oxidoreductase (SQOR) that metabolizes hydrogen sulfide. To verify that higher levels of this enzyme translated to better hypoxia tolerance, the scientists artificially increased SQOR levels in a separate group of mice and found that they were also much less affected by hypoxia than the untreated control group.

Unfortunately, human brains naturally have low levels of SQOR, making us particularly susceptible to hydrogen sulfide accumulation. However, this new research gives scientists a clear path towards protecting our brains from the effects of hypoxia by developing a drug that either increases levels of the SQOR enzyme or mimics its function. From strokes to cardiac arrests to severe brain injuries, such a drug could save many lives.

Beer is one of the oldest drinks that humans have made. And in a recent study, a pair of scientists from the Université de Reims Champagne-Ardenne have drawn attention to a dazzling event that occurs every time we pour a cold one in a glass, by focusing on a key ingredient, carbon dioxide (CO₂).

Beer is a liquid supersaturated with carbon dioxide gas. While contained in a sealed bottle, a high pressure keeps CO₂ dissolved in the liquid in a larger amount than would normally exist at atmospheric pressure. But when the bottle is opened, CO₂ quickly escapes into the air producing a wave of bubbles and foam.

No matter if you brew it at home or buy it the bubbles of carbon dioxide in your beer can be just as important as, of course, beer taste and texture. Bubbling can impact the bite and fizziness that you experience as the bubbles pop in your mouth as you take a sip. And not only that, “[also] the visual aspect and the release of aromas above the glass,” lead author Gérard Liger-Belair said.

The scientists compared bubbling in beer with the same feature of champagne. They found that pouring a chilled Heineken over a tilted glass produced about 1.5 million bubbles – not very different from champagne, which produced slightly over 1 million bubbles. However, the number of bubbles produced was dependent on the size of microcrevices in the glass. Microcrevices are sites on the surface of a glass wall that are only visible with a microscope, and they are where bubbles originate. They can span from 1 to 10 micrometers in size, roughly as small as a grain of sand.

Another key finding was that champagne contained about five times more dissolved CO₂ than beer. And surprisingly, the amount of CO₂ dissolved in beer was only a little over that of carbonated water. In addition, beer bubbles were smaller than champagne bubbles and move through the drink differently.  Smaller bubbles are preferred in champagne, according to Liger-Belair, “Mainly because small ascending bubbles rise more slowly which is more elegant.”

Regardless of your beverage of choice, perhaps now you will be more interested to resist your first sip of beverage to enjoy the playful and spectacular bubble dynamics in your glass.

Since its successful landing this February, the Perseverance rover has been prowling Mars in search of signs of life, past or present. Its hunting ground in Jezero Crater is rich in carbonate minerals that are hardy enough to have preserved microscopic fossils for billions of years, meaning that NASA’s new rover might have a shot at finding fossil evidence of alien life.

If Perseverance does find something that looks like it could be a microfossil, scientists on Earth will probably still need to wait for sample return before they can make the final call using more powerful analytical methods available in Earth labs. Determining whether microbe-shaped mineral blobs and filaments are truly microfossils is not always straightforward. Usually, researchers use biogenicity criteria — checklists of characteristics thought to be diagnostic of biological origin — to evaluate potential microfossils. But a recent study published in the journal Gebiology suggests that even with biogenicity criteria, it might not always be possible to distinguish faux fossils from the real deal.

To test the limits of biogenicity criteria, researchers analyzed mineral microfilaments in rocks that formed under Mars-analogue conditions in Earth’s subsurface. They showed that these microfilaments fulfilled many published biogenicity criteria, despite also looking nearly identical to completely inorganic structures formed in microbe-free chemical garden experiments. Given these results, and because the geochemical conditions in which the samples formed could feasibly explain these “dubiofossils,” the researchers argue that we still can’t be sure that they’re microfossils — even though they passed biogenicity criteria. 

Determining the biogenicity of mineral microstructures is hard enough on Earth, where life is a reasonable hypothesis. On Mars, it is the hypothesis of last resort. Every possible abiotic explanation for possible life found on the red planet needs to be eliminated before biology can be considered a reasonable explanation. The search for life beyond Earth will thus rely on our ability to do just that.

Wallabies: they are cute, relatively small, and “exotic” to European audiences. These circumstances led to the introduction of red-necked wallabies, an Australian species, early in the 20th century to countries like England, Ireland, and France. At that time, wallabies were kept in zoos and private collections. Some escaped, especially during World War II when people had more important things to think about than fence maintenance.

In England today, there is little information available about the fate of those introduced wallabies. Two researchers, Holly English and Anthony Caravaggi, wanted to know what happened to those wallabies. They collected information on wallaby sightings by scouring through official records, social media, and newspapers. Thanks to the wallabies’ cuteness and distinctiveness compared to other animals, sightings were often reported in local news.

In their recent article, published in Ecology and Evolution, the researchers found small populations living throughout southern England. It seems wallabies can survive in England and potentially even breed. While some of the wallabies they found are probably escapees from current private collections and zoos, such escapes are unlikely to account for all wallaby sightings in the region.

So, if you are ever in southern England, and think you spot a wallaby, don’t be too surprised!

Academic papers used to be locked behind paywalls — many still are. Researchers at universities without large budgets to pay journal subscription fees, as well as members of the public, are often unable to access academic research unless they paid for it themselves. This situation has started to change thanks to a push towards open access publishing, which aims to make all research freely available and accessible to everyone.

But open access publishing comes with its own difficulties and obstacles. Some forms of open access require the author (or the author’s funder or institution) to pay a substantial fee, known as an article processing charge, so that the journal will publish their paper without a paywall. For example, in November of last year, the publisher Nature set the open-access fee for a subset of their journals at a staggering $11,390. Another obstacle is that fully open access journals don’t always have great reputations.

These obstacles to open-access publishing may hit researchers without much funding or job security especially hard. A recent study by a pair of scientists from the Academic Analytics Research Center analyzed which US researchers wrote open access papers from 2014 to 2018.  They found that researchers who are male, have won federal grant funding, are affiliated with prestigious institutions, and/or work in STEM are more likely to have open access papers. In other words, the most privileged researchers in STEM disciplines are over-represented in the open access literature.  

This means that important research by less privileged researchers is less likely to be freely available to all and, given the citation advantage of open access work, this means it is more likely to be ignored or overlooked. Despite its admirable intentions, the open access movement has work to do to ensure that open access literature better represents the full diversity of academia.

The latest social media challenge trying to go viral is weird — perhaps you have already seen it on TikTok, Twitter, or Instagram. If you haven't, don't be alarmed if you hear friends talking to you about turning your poop blue. 

Believe it or not, your poo provides you with a lot of important health information. A company called ZOE is looking to help you understand how. If you are interested, you can turn your own poo blue for free and receive health insights.

A recent paper from microbiome scientists, including researchers affiliated with ZOE, used a blue dye to help assess gut transit time, the amount of time for the food you eat to travel through your body, in 863 individuals. Gut transit time is associated with specific components of the microbiome. So, long with dietary information, gut transit time provides clues to the identity of microbes in your gut. The researchers found that longer gut transit time was associated with specific species of microbes: Akkermansia muciniphila, Bacteroides spp and Alistipes spp. Gut transit time was a better indicator of gut health than frequency or consistency. 

You can now follow the recipes provided by ZOE to bake muffins with blue dye, track how long it takes for your poop to come out blue, and use this time to determine if your gut is currently in a healthy state. If you try it, join the #BluePoopChallenge on Twitter, Instagram, and TikTok.

As the pandemic persists, more information about the SaRS-CoV-2 virus and its effects emerges from labs across the world. Now, a team of researchers from Yale University has found that COVID-19 patients show increased amounts of autoantibodies, antibodies which can attack human tissues and cells. The study, conducted on 194 people diagnosed with COVID-19, used a novel screening tool to determine the proteins that were affected by these autoantibodies. 

The discovered that more autoantibodies that target immune-related cells were present in people with COVID-19 compared to uninfected people. Since these autoantibodies interfere with and attack cells involved in the immune response, this can cause people with COVID-19 to have fewer immune cells than people without the disease. This can then lead to longer recovery time for those people, as their immune systems are less able to effectively remove the virus from their bodies. 

The study also showed that mice injected with autoantibodies were more susceptible to COVID-19 infection, and this effect may occur in humans who already have these autoantibodies. However, more research on this topic needs to be conducted before conclusions about this effect can be drawn. 

Walking takes little brain power, but it does require energy. In fact, it is the most energy-intensive activity that we do as part of our daily lives. What if we could put on an exoskeleton that worked with our muscles to ease some of the metabolic burdens of walking? Such a suit could assist in accident rehabilitation, help outdoor adventurers or on-foot search parties hike longer with ease, and even make day-to-day activities like running errands less taxing. 

In a study recently published in the journal Science, a team of engineers from Queen's University in Canada developed a backpack-mounted exoskeleton that reduces the metabolic cost of walking by 2.5 percent. At the same time, the device harnesses energy produced by walking and converts it to 0.25 watts of electricity (for reference, cell phone chargers generally use about 2-6 watts of electrical power). 

Weighing approximately two pounds, the exoskeleton consists of cables that run parallel to a user’s hamstrings and attach to their ankles. The cables feed into pulleys on the user’s back, which connect to a generator. The system works by helping slow the leg down during the late "swing phase" of the walking cycle, after the leg has extended forward and the foot is about to touch the ground. Essentially, the device helps the hamstrings "put on the brakes". The generator powered through this resistance converts the energy into electricity. This electrical power could then be used to supply people with electricity or powered, assisted movement.

This study, among others, illustrates that exoskeletons are not a futuristic fantasy, but a real possibility. It points to practical implications for exoskeletons beyond assisting mobility,. As exoskeletons become more wearable, intuitive, and optimized, they have a greater chance of entering the mainstream market. Some day, we may all have an exoskeleton in our closets.

This is part of Stoned Science — science that makes you go "whoa." Or is it woah?

If lighting up makes you want to snuggle up, then it's good thing you're not bacteria — otherwise those innocent post-brownie cuddle puddles might end up leaving you with some extra DNA you didn't ask for. When they get close enough, certain bacteria share packets of DNA with each other in what essentially looks like a super intimate handshake or hug. 

This process is called bacterial conjugation, and it's about as close as bacteria get to sex. But unlike sex, conjugation isn't a reproductive process. Instead of leading to new bacteria, it transfers genes from one existing bacterium to another. 

One partner, called the donor, builds a little appendage called a pilus out of protein and uses it to connect with the recipient cell, reeling it in for a close embrace. The two temporarily fuse a small section of their cell membranes, allowing the donor to transfer a bit of DNA to the recipient. Usually, the two bacteria simply exchange DNA and then go on their merry ways. But certain bacteria can end up scrambling their genomes so thoroughly that they emerge from their liaison as hybrid mixtures of each other. 

But conjugation isn't all innocent hugs and good vibes. It has a dark side. Gene transfer via conjugation is so important for spreading antibiotic resistance that some scientists have even proposed developing drugs that target conjugation systems as a way to gain the upper hand in the antibiotics arms race. 

Talk about a mood killer. 

Anyone with a cat (or internet access) has likely observed their tendency to seek out and sit in boxes, bags, baskets, and even a simple square drawn on the ground, as demonstrated by Twitter’s #CatSquare trend.

A team of psychologists decided to use this feline behavior to investigate whether cats are susceptible to a well-known visual illusion: the Kanizsa square. A Kanizsa square is made of four small solid-colored circles, each with a right angle cut out so that only ¾ of the circle remains. These circles are arranged in a large square shape and rotated so that the missing parts face inwards, creating the illusion of an actual square sitting above them.

A 1988 study provided some evidence that cats perceive the Kanizsa square the same way that humans do, but that study only included two cats trained in a lab. Scientists behind a recent study, published in Applied Animal Behaviour Science, wanted to test a wider range of cats and capture their natural behavior at home. To do this, they turned to social media to recruit participants.

They asked cat owners to cut out three different stimuli: a real square, a Kanizsa square, and a rotated Kanizsa in which the circles were turned outwards, causing the illusion to fail. Each day, the cat owners placed two of these stimuli on the floor and then watched their cat for five minutes.

Thirty cats were tested over six days, and among them, they sat within the real square eight times, the Kanizsa square seven times, and in the rotated Kanizsa only once. In the trials where the cats had a choice between the real square and the Kanizsa square, they showed no preference between them. This indicates that cats may perceive illusory squares to be as valid, and as comforting, as real squares.

So, in addition to showing that cats really do like sitting in two-dimensional squares, the researchers also demonstrated that cats perceive some of the same visual illusions that humans do. Despite the many differences in the eyes and brains of humans and cats, we may see and interpret our environment in strikingly similar ways.

Half the cells in our body aren't human. Don't worry, these non-human cells aren't harmful. In fact, they're crucial to your health and make you, you. Trillions of bacteria, viruses and fungi flourish within us. We co-evolved with the microbial community living in our guts. Microbial signaling plays a crucial role in maintaining our health. 

As our society became industrialized, we lost many microbes that once lived within us. Could any of these missing microbes help us develop new treatments? 

Often, scientists look at modern hunter gatherer societies to study microbiome industrialization. Instead of relying on these humans as a proxy, scientists extracted DNA from ancient poop. It dated back between 1000 and 2000 years old, found in rock shelters in Utah and Mexico. They published their glimpse into the ancient gut microbiome in Nature in May.

In analyzing eight ancient poop samples, the researchers travelled back in time. They found overlap between modern hunter gatherer societies and the ancient poop.  Roughly two of every five bacterial genomes extracted from the ancient poop were new. These never-before seen microbial species likely went extinct as we became more industrialized. 

Diet is only one of many factors that changed our microbiomes. As we sequence more ancient poop, we will zero-in on the factors shaping the modern microbiome. 

Scientists found so many new species in only eight samples. Of course, these samples are precious and limited. It is rare that we find these well-preserved specimens. But as out sequencing technology improves, we might be able to extract more information from ancient poop.

Homo sapiens emerged around 300,000 years ago in Africa, and traces of modern use of symbols in our species date back around 160,000 years . Today, humans are considered unique in the natural world for the universality with which we symbolically commemorate the deceased. Despite this, the oldest known burial in Africa was only 74,000 years old — until now.

In a new study, a team of researchers described the oldest burial in Africa to date, containing the nearly 80,000 year old skeleton of a 2.5 to 3 year old child in a cave off the coast of South Africa. Several features of the burial, including the change in soil color and texture, indicate that the pit was created intentionally, rather than an existing natural feature.

According to their analysis, the child was placed in the pit shortly after death, before the tissues could deteriorate, which would displace the bones. However, some bones in the upper body were rotated, suggesting that the child had been partially wrapped in and supported by a perishable material. Interestingly, though the researchers identified the child as belonging to Homo sapiens, they note that some dental features differ from those seen in humans today — those differences resemble dental patterns found in Neanderthals.

Older human and Neanderthal burials dating to the same archaeological period have been previously found in the Levant. This new find highlights the biological and cultural diversity of different hominin populations during this period, and showcases the care with which individuals were buried tens of thousands of years ago.

Textile dyes are one of the leading causes of water pollution. The dyeing process uses lots of water, and much of this water ends up in nearby rivers and streams. And dye wastewater, such as the effluent from denim production, contains dangerous chemicals. Toxic chemicals are also sometimes left behind in your clothes after the dyeing process.

Bioengineering bacteria and fungi is one way to reduce the environmental impact of dye production, since it can reduce the amounts of dangerous chemicals needed in the process. In a recent study published in ACS Sustainable Chemistry & Engineering, biomolecular chemists injected DNA into a type of bacterium, Corynebacterium glutamicum, that already produces the building blocks of the blue dye, indigoidine. The specific segment of DNA, a "blue-pigment indigoidine synthetase" gene, allowed the bacteria to put those building blocks together. The bacteria produced large amounts of the dye, which the scientists then used to color white cotton.  

If scientists can engineer bacteria that produce dye at a level comparable to industry, we could see a shift towards the use of these greener methods in the textile industry. This will lead to greater sustainability in an unsustainable industry. 

Yesterday scientists and photographers took to Twitter to celebrate International Invertebrate Butt Day, or #invertebuttfest. Some of them are fuzzy. Some are wet and slimy. Many are literal hard-asses, strengthened by one of nature's toughest materials called chitin. The niche trend is also taking place in honor of biologist Maureen Berg's birthday. (Berg has previously given talks about invertebrate butts, and has previously called for June 9th to be Invert Butt day.)

"The whole idea is that, we love butts, especially invert butts, and decided that there should be a dedicated day to celebrating them," Berg says. "Invert butts should be celebrated because they have a wide diversity in form and function, and because they bring us all joy."

We at Massive have a soft spot for butts. We, in fact, dedicated a whole month to them. That's because butts are fascinating. Humans have evolved anatomically interesting ones, and we use their deposits to track disease. Other animals evolved to literally be a butt's output, to escape predators. And butts can be important tools for animal scent-based communication. 

Invertebrate butts are of course, nothing like ours. Spiders aren't fleshy and bees don't have anuses. But there's no reason to identify part of their anatomy as a butt in any case. The precise definition of a butt is a bit arbitrary. In an interview last year, ecologist and butt science author Dani Rabaiotti told Massive: "I usually just refer to any end of an animal that’s opposite its head as a butt." So there you have it, scientific validation for the ubiquity of butts. Here are some of our favorites invertebutts:

Astronomers have just released three newly processed images of Jupiter at three different wavelengths, a combination of photos from the Hubble Space Telescope and the Gemini North telescope in Hawai’i that were taken in January 2017. By observing the planet at infrared, visible, and ultraviolet wavelengths of light and comparing the images to radio signal detections by the Juno spacecraft, scientists can better understand Jupiter's atmospheric phenomena such as wind patterns and cyclones. The radio signals detected by Juno correspond to blasts of lightning in Jupiter’s atmosphere. The location of these signals can be mapped to the images to see which types of clouds are present and how they move over time. More information about the science behind these images was published last year in The Astrophysical Journal.

Image diversity is important because each wavelength “sees” through different layers of the atmosphere. For example, the Great Red Spot is clearly visible in both the ultraviolet and visible images, but appears as a bright crescent in the infrared image. This glowing semicircle represents a gap in the clouds, a feature distinguishable with longer wavelength infrared light that can penetrate the upper atmospheric layers of thin haze. However, the gap is hard to detect with visible light since that haze is almost the same color as the thicker storm clouds surrounding it. In the ultraviolet image, the Great Red Spot appears larger and more uniform since the shorter wavelength ultraviolet light mostly captures the haze, obscuring features of the spot in lower layers that can be seen with visible light. In this way, each image is a separate piece of the puzzle, together giving more insight into what’s actually happening on the planet.

Ultimately, the trifecta of the Hubble, Gemini, and Juno will enable scientists to track changes in Jupiter’s atmosphere and perhaps even provide insight into one of the planet’s biggest mysteries: Why is the Great Red Spot shrinking?

Cancer is a disease in which abnormal cells divide uncontrollably. Most cancers start due to gene mutations which accumulate over the course of an animal’s life. Each time a cell divides, there is chance that the genes within the cell will mutate. If genes which control the normal growth, division, and death of cells become mutated, the cell can become cancerous. Theoretically, the longer an animal lives and the more cells within its body, the higher the chances are that enough mutations will accumulate for cancer to develop — but not always.

Whales, dolphins, and porpoises belong to a group collectively known as cetaceans, containing some of the largest and longest-lived species of mammals on Earth. Yet, cetaceans have some of the lowest cancer rates. This lack of cancer suggests cetaceans must have evolved effective cancer suppression mechanisms which humans and other mammals lack. 

Researchers trying to better understand how cetaceans suppress cancer studied the evolution of over 1000 tumor suppressor genes, or TSGs in 15 mammalian species, including cetaceans. TSGs are known to affect cell division, repair mistakes in DNA, and control when cells die — important processes for keeping cancer at bay. Published in Proceedings of the Royal Society B, their results show that over time cetacean species including orcas and bowhead whales had positively selected TSGs that are linked to a variety of cancers. The team also found that cetacean species gained and lost genes at a rate more than double that of other mammalian species, which may have accelerated evolution of TSGs in cetaceans. 

These findings point to the evolutionary mechanisms that allowed large, long-lived species to overcome the threat of cancer. By studying the genes implicated in cancer suppression and understanding how they might do so, researchers may gain useful insights into how to suppress cancer in humans.

On May 14, China successfully landed a rover on Mars with its Tianwen-1 mission, becoming the second country to land a rover on our neighboring planet. The Zhurong rover now joins the handful of American rovers — Sojourner, Spirit, Opportunity, Curiosity, and the current Perseverance mission — already on the Red Planet. This historic event follows right on the tails of another nation’s first success: the United Arab Emirates’s first interplanetary spacecraft, a Mars orbiter known as Hope, which reached the planet's orbit in February.

The Zhurong rover is about 500 pounds (the weight of a male black bear), much smaller than the newer, heftier NASA rovers. Zhurong is powered by solar panels and expected to operate for only about three months, although other rovers have lasted far longer than their planned missions. It’s accompanied by the Tianwen-1 orbiter, which released its lander down onto the Martian surface and now serves as a communications relay. The orbiter will survey the surface and report to the lander where it should investigate further, while the rover will explore the surface geology and map the distribution of water-ice. 

The Tianwen-1 lander, carrying the Zhurong rover, touched down in Utopia Planitia, a region also visited by the Viking 2 lander. This is a particularly interesting region for the search for life, since previous evidence suggests that water-ice might be lurking under the surface here. The rover is equipped with cameras, ground penetrating radar, a spectrometer, and even a magnetometer — the first on a Martian rover. Measuring the Martian magnetic field might clue scientists in as to why Mars lost its atmosphere billions of years ago, making it the uninhabitable place it is today. 

This successful first for China opens the door for future exploration such as a planned sample return by the 2030s, adding yet another crucial tool to humanity’s search for water and life on the Red Planet.