Learn about why mRNA vaccines are older than you think; and the scientific theories about why animals have white bellies. mRNA vaccines are older than you think by Grant Currin Dolgin, E. (2021). The tangled history of mRNA vaccines. Nature, 597(7876), 318–324. https://doi.org/10.1038/d41586-021-02483-w Lewis, T. (2021, September 15). An mRNA Pioneer Discusses How Her Work Led to the COVID Vaccines. Scientific American. https://www.scientificamerican.com/article/an-mrna-pioneer-discusses-how-her-work-led-to-the-COVID-vaccines/ Harvard University. (2021). How mRNA vaccines work [YouTube Video]. In YouTube. https://www.youtube.com/watch?v=TbaCxIJ_VP4 Why do so many animals have white bellies? Here are the theories by Cameron Duke Exhibit Galleries Blog. (2016). Neaq.org. http://galleries.neaq.org/2014/09/countershading-camouflage.html Harris, J., & Olivier Penacchio. (2015, October 7). Sunscreen or camouflage? Why so many animals have dark backs and pale bellies. The Conversation. https://theconversation.com/sunscreen-or-camouflage-why-so-many-animals-have-dark-backs-and-pale-bellies-48603 Penacchio, O., Cuthill, I. C., Lovell, P. G., Ruxton, G. D., & Harris, J. M. (2015). Orientation to the sun by animals and its interaction with crypsis. Functional Ecology, 29(9), 1165–1177. https://doi.org/10.1111/1365-2435.12481 Penacchio, O., Lovell, P. G., Cuthill, I. C., Ruxton, G. D., & Harris, J. M. (2015). Three-Dimensional Camouflage: Exploiting Photons to Conceal Form. The American Naturalist, 186(4), 553–563. https://doi.org/10.1086/682570 Follow Curiosity Daily on your favorite podcast app to learn something new every day withCody Gough andAshley Hamer. Still curious? Get exclusive science shows, nature documentaries, and more real-life entertainment on discovery+! Go to https://discoveryplus.com/curiosity to start your 7-day free trial. discovery+ is currently only available for US subscribers.
Learn about why mRNA vaccines are older than you think; and the scientific theories about why animals have white bellies.
mRNA vaccines are older than you think by Grant Currin
Why do so many animals have white bellies? Here are the theories by Cameron Duke
Follow Curiosity Daily on your favorite podcast app to learn something new every day with Cody Gough and Ashley Hamer. Still curious? Get exclusive science shows, nature documentaries, and more real-life entertainment on discovery+! Go to https://discoveryplus.com/curiosity to start your 7-day free trial. discovery+ is currently only available for US subscribers.
Find episode transcript here: https://curiosity-daily-4e53644e.simplecast.com/episodes/mrna-vaccines-are-decades-old-and-why-white-animal-bellies
CODY: Hi! You’re about to get smarter in just a few minutes with Curiosity Daily from curiosity-dot-com. I’m Cody Gough.
ASHLEY: And I’m Ashley Hamer. Today, you’ll learn about why mRNA vaccines are older than you think and why so many animals have white bellies.
CODY: Let’s satisfy some curiosity.
The COVID-19 vaccines were produced in record time. In less than a year, researchers and engineers who’d never seen the SARS-CoV-2 virus managed to develop an innovative vaccine, test it, and start the long process of manufacturing enough of the stuff to protect billions of people from dying from the virus.
Does that mean the vaccine was invented in less than a year? Well, not exactly.
The Pfizer and Moderna vaccines have been hailed as biomedical breakthroughs because they work differently from most vaccines that have been used in the past. The shots use a molecule called messenger ribonucleic acid — that’s mRNA for short. mRNA is what your body uses anyway to produce the millions of proteins it needs to do what it does. When the tiny mRNA molecules of the COVID vaccine are injected into someone’s arm, they direct some of that person’s cells to make off-brand versions of a protein found on the real coronavirus. The immune system studies the harmless knock-offs to prepare for future encounters with the real thing.
But here’s the surprising part: using mRNA to our advantage is nothing new. Researchers first discovered the stuff in 1961, and it didn’t take long for them to figure out how to use it to instruct cells to make the proteins they wanted. That was in the lab, but it’s the same principle that’s behind the vaccine currently being delivered to millions of people every day.
Researchers knew about mRNA for nearly 20 years before starting to think about how it could be used as medicine. As recently as 2000, hardly anyone was willing to invest money in attempts to make RNA-based medicine a reality.
That seems silly today, but it’s because there were a lot of hurdles to clear. For instance, in the early 2000s, researchers working on an mRNA vaccine for HIV realized their creation was accidentally setting off an alarm in the immune system. Luckily, in 2005, the scientists working on that vaccine figured out that tweaking a few letters in the genetic code made the problem disappear. They didn’t know it at the time, but those researchers were helping invent the new COVID vaccine!
And it’s looking like their contributions might extend far beyond that one vaccine. Before the pandemic started, labs across the world had already spent years working on mRNA treatments for conditions like cancer and HIV.
It’s still too early to say which diseases mRNA technology will actually be able to prevent, but the pandemic has put us much closer to answers. That’s because COVID didn’t just put the new vaccine technology into the spotlight. It also expedited the clinical trials. That should make it much easier for researchers working on other mRNA vaccines to find out if their creations are safe and useful.
Ok, Cody, how many animals can you name that have a white belly? [AD LIB] There are so many! When an animal has a pattern of having a darker pigment on the upper surfaces of the body than the unilluminated lower areas, scientists call that countershading. But the funny thing is that scientists don’t really know why this pattern exists. Of course, that doesn’t mean there aren’t some pretty good ideas. So let’s talk about some!
The first hypothesis scientists kicked around to explain countershading is that it provides protection against ultraviolet light. More melanin in the skin, fur, or feathers on animals’ backs might act as a type of natural sunscreen that would protect them from the sun’s damaging rays while providing a little extra warmth for the animal too. That’s not as necessary on their undersides, so their bellies stay pale.
Other scientists believe that countershading can act as a universal camouflage. Like, if a shark is swimming above you during the day, you’d usually see a dark shadow against the bright surface. But if the shark has a white belly, it might blend in better against the backdrop of sunlight. Iif you’re above the shark, its dark back might blend in with the murky depths.
This seems plausible, but it’s hard to imagine how the same idea might apply on land, where animals are more often viewed from the side. In this case, a pair of recent studies proposed a third mechanism, and it throws some shade on the other ideas. Essentially, the researchers argue that no matter where an animal lives, more light comes from above than below. A uniformly colored object, in this case, would be brighter on top than on the bottom, which creates a shading pattern that would be very easy to spot. After all, that pattern applies to pretty much all 3D shapes, so animals have evolved to detect it.
But if an object was darker on top than it was on bottom, it might cancel out the pattern and blend in with its surroundings. That could be what’s behind countershading. Maybe it’s an evolutionary attempt to counteract the natural effect of illumination.
The researchers suggest that variations on countershading might have to do with the particular environment the animal lives in. For example, deer that live in open savannas have brown flanks, white bellies, and a dark strip of fur along the spine. Scientists think this may be an optimal pattern for countershading in intense sunlight.
In the end, it’s hard to say for sure why countershading is so common among so many animals. But hopefully, future studies will be able to shed more light on the answer.
CODY: Before we recap what we learned today, [PLUG FOR 1000TH EPISODE LIVESTREAM]
Let’s recap today’s takeaways
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ASHLEY: Today’s writers were Grant Currin and Cameron Duke.
CODY: Our managing editor is Ashley Hamer.
ASHLEY: Our producer and audio editor is Cody Gough.
CODY: [AD LIB SOMETHING FUNNY] Join us again tomorrow to learn something new in just a few minutes.
ASHLEY: And until then, stay curious!