Curio Cabinet

Orange you glad they’ve solved this kitty mystery? After years of puzzlement, scientists now know what gives ginger cats their distinct orange coloration, and why so many orange cats are male. Owners of orange cats have long posited that there’s something special about them. They tend to have sillier, more laid-back personalities than average cats, and that temperament has earned them devoted followers. Among them is Professor Hiroyuki Sasaki, a geneticist at Kyushu University in Japan who crowdfunded his effort to unravel the secret behind the cats' unique fur. Scientists knew that there had to be a unique genetic link between their fur color and their sex, since orange cats are overwhelmingly male just as calico cats are overwhelmingly female. Sasaki and his colleagues raised around $70,000 to perform their research, mostly from fellow cat lovers. Their efforts paid off, and the culprit was identified: the ARHGAP36 gene, or rather, a mutation in the X chromosome that deleted a section of it in some cats. The ARHGAP36 gene is responsible for pheomelanin, the type of melanin responsible for red, orange, and yellow pigments in mammals, as opposed to eumelanin, which controls brown to black pigment. In cats with the mutation, the ARHGAP36 gene goes haywire, producing much more than it normally would. That it only occurs in the X chromosome also explains the skewed sex ratio. Since male cats only have one X chromosome, the mutation goes uncorrected. Meanwhile, female cats require the mutation to exist in both of their two X chromosomes. If only one is affected, they end up as calicos. But there might be more to the gene than meets the eye. The ARHGAP36 gene might also play a role in orange cats’ personalities. The gene is responsible for other functions in the brain and hormonal glands, so it’s possible that it produces unique inclinations and behaviors. Now if only we knew why we love cats even when they’re indifferent to us.

 
[Image description: An orange tabby cat lying on gray carpet.] Credit & copyright: Brian Adler, Wikimedia Commons.

You might be chill, but are you capybara-level chill? Capybaras are famous for two things: being the world’s largest rodents and having one of the most relaxed dispositions in the entire animal kingdom. Their penchant for getting along with other creatures, from birds to caimens, has made them internet darlings. It’s also helped them survive for millions of years without having to change much.
 
Capybaras are the largest rodents on Earth, standing around two feet tall and four feet long while weighing up to 146 pounds. That’s awfully big considering that most rodents, like mice and squirrels, are some of the world's smallest mammals. No one knows for certain why capybaras evolved to be so huge. It could be that they grew to their current size during a time when food was particularly plentiful in their South American habitat. Or it could simply be genetic luck. Capybaras evolved from a much smaller ancestor around the same size as a guinea pig. A mutation might have caused gigantism to become more common in capybaras, making them grow large. Normally, species with such mutations have higher rates of cancer, but research has shown that capybaras also evolved cancer-resistant genes, even as their main growth hormone, called IGF-II, increased.
 
Whatever caused it, there’s no doubt that capybaras’ large size serves them well. Once capybaras are adults, few animals bother to prey on them (though some, like jaguars and caimans, still occasionally do.) Capybaras are most vulnerable to predation when they’re young, but since capybaras have up to eight babies at a time with a relatively short gestation period of five months, their populations have managed to remain stable. Capybaras are semi-aquatic, spending much of their time swimming and soaking in water. After a good swim, a capybara herd, which can consist of up to 30 capybaras, will lie along a river to dry their fur. They don’t mind much when birds land on their backs or even when predators like caimans come to rest beside them. Part of capybaras’ laid back attitude is due to their slow metabolism. They mostly eat grass, which takes time to break down. This means that they spend much of their energy on digestion and can’t expend too much on anything else. They also don’t have much reason to be wary, due to their size and the fact that their herds help keep them safe. There’s power in numbers, including the power to take it easy.

 
[Image description: Two capybaras in a zoo enclosure, one sitting and one standing.] Credit & copyright: Adrian Pingstone (Arpingstone), Wikimedia Commons. This work has been released into the public domain by its author, Arpingstone. This applies worldwide.

When it comes to the end date of the universe, what's a few orders of magnitude? Scientists at Radboud University in Nijmegen, Netherlands, have found that the universe might end much earlier than expected—but it's still a very, very long way away.
 
Estimating the universe’s remaining days might seem like an unfathomably impossible task, but physicists have come up with a few ways to figure it out. One method involves calculating how long it takes for stars to die. Larger stars collapse in on themselves, cause supernovas, and become black holes. Smaller stars will leave a nebula when they die, as well as a hot, dense core called a white dwarf. Most stars in the universe will become white dwarves in about 17 trillion years, but the story doesn't end there. Both white dwarves and black holes decay over time, and they do so at an astronomically glacial pace. Their decay releases Hawking radiation, named after the late astrophysicist Stephen Hawking, who first predicted the process.
 
Hawking only ever posited that black holes would decay in this way, but the scientists at Radboud University believe that white dwarves can also decay similarly. Since white dwarves were believed to linger on much longer, it was believed that it would take around 10 to the power of 1,100 years for the last remaining stars to die out for good. However, if they decay similarly to black holes, that number comes way down. That's not to say that it will happen anytime soon. It will still be another 10 to the power of 78 years, or one quinvigintillion years. By then, there certainly won't be anyone left to say, "Lights out!"

 
[Image description: A starry sky above a line of dark trees] Credit & copyright: tommy haugsveen, Pexels

There's something in the air nowadays…or less of something. Researchers at Tianjin University and Peking University have found that mercury levels in the atmosphere have been dropping steadily over the past few decades, according to a study published in ACS ES&T Air. It's difficult to overstate the dangers of mercury, and much of the heavy metal in the atmosphere is anthropogenic, meaning that it originates from mad-made pollution. Whether it's elemental mercury or methylmercury, the latter of which is present in certain types of fish and shellfish, mercury has neurotoxic effects that can range from debilitating to deadly. Fortunately, anthropogenic mercury appears to be on the decline. Researchers pored over data from the past four decades and found that more of the mercury in the atmosphere appears to be from the re-emission of terrestrial mercury in the soil. In the last 20 years, atmospheric mercury levels plummeted by 70 percent, and it might be the result of the Minamata Convention on Mercury, an international treaty that regulates sources of mercury pollution. Much of this data was found by examining Androsace tapete, a plant that grows on Mount Everest and sprouts a new layer of leaves each year. The leaves from each layer contain varying levels of mercury depending on the year. Thus, researchers were able to track the declining presence of the toxin over the decades. It seems that plants are surprisingly good record-keepers.

[Image description: A white cloud against a blue sky.] Credit & copyright: Wikimedia Commons, Dinkum. This file is made available under the Creative Commons CC0 1.0 Universal Public Domain Dedication.
 

It's time for this conductor to face the music—and lead the orchestra! A conductor in Ohio who was diagnosed with Parkinson's disease 11 years ago was recently given a cutting-edge implant that some are calling a "pacemaker for the brain”, allowing him to conduct without shaking. While more invasive than previous treatments, it might give hope to those with difficult-to-manage symptoms.
 
For nearly 50 years, Rand Laycock has been living his dream of conducting a symphony orchestra in Parma, Ohio. But for the past decade, he's also been struggling with Parkinson's, which threatened his passion and livelihood. What started as a minor twitch in his thumb developed into worsening tremors in his right hand, and the very medications used to treat him also gave him dyskinesias—erratic, involuntary movements that are, unfortunately, a common side effect.
 
The symptoms of Parkinson's can vary widely, but can include changes in speech, rigid muscles, difficulty moving, and balance issues. Less noticeable are the psychological symptoms like depression and anxiety. Parkinson's is also a degenerative disease that gets worse over time and can lead to death, even with treatment. Fortunately, Laycock was able to be treated with deep brain stimulation (DBS), which uses implanted leads that deliver therapeutic amounts of electric currents to curb the worst of the symptoms. However, Laycock's symptoms were particularly difficult to treat because they tended to fluctuate in severity. That meant that they could flare up in the middle of a performance. Now, he's being treated with adaptive deep brain stimulation (aDBS), which can vary the electric currents to meet the changing needs of Laycock's condition. Thanks to the aDBS implant, Laycock can continue to perform his duties at concerts reliably. Even Parkinson’s is no match for advanced medical engineering.

 
[Image description: A digital illustration of a gray human brain against a black background.] Credit & copyright: KATRIN BOLOVTSOVA, Pexels