WRFH/Radio Free Hillsdale 101.7 FM - Visible Things: Fly Brains

Episode Date: March 19, 2025

Fly brains are the size of a poppy seed yet contain an enormous amount of complexity and evidence for design. This week Eleanor discusses last fall’s release of a fly brain map and how it displays its Creator. Also, Eleanor geeks out about tardigrades, Mars, and glass brains.

Hello and welcome to Visible Things, the science news show that investigates the biggest mysteries in our visible world while honoring our invisible creator. I'm your host, Eleanor Whitaker. And today's Visible Thing will make you pause before you pull out your fly swatter to smack that annoying fly in your room. Last week, we took a look at complexity in something big, the universe. And today, we're shifting to challenge the assumptions that small things are less complex by taking a look at a fruit. fruit flies brain. Yeah, that's right. Last year, one of the biggest news stories of the year was scientists unveiled a map of a fruit flies brain and every single neuron had a name, a category, and a structure to it. Today, we're going to talk about why this map is significant, how it shows

the amazing creativity of our creator, and what it means for humans as we study our own brains. That's coming up on visible things. But first, let's dive into the news stories for the week. The key to fighting the side effects of cancer might lie in a tiny microscopic organism called a tardigrade. Radiation therapy sucks for a lot of people who undergo cancer treatment because radiation is designed to try to kill the tumor inside of a body. Radiation is extremely effective at killing cells. In the process, it ends up killing human cells as well, causing radiation sickness, other problems, even sometimes more cancer itself.

But scientists are looking to tardigrades as a solution to this problem. Tartagrades are one of my favorite animals. You might also know them as water bears or my favorite name, moss piglets. They're less than a millimeter in length, only seen under a microscope. They can be found almost anywhere, including moss in your backyard. But they're known to withstand extremely high temperatures, pressures, radiation, dehydration, and outer space. They're the superheroes of the animal world. throw anything at them and they can probably handle it.

Because of their resilience to radiation, scientists are like, well, maybe whatever is in the genes of the tardigrades can help humans withstand radiation themselves. So scientists took out of a tardigrade a molecule called a messenger RNA, which if DNA is the ingredients list and ingredients instructions for how to create proteins, RNA is kind of like the baker that reads the instructions and ingredients and then goes and tells other molecules how to put them together and goes and helps create the proteins. So they took this piece of RNA that has instructions and coding how to make proteins on it from the tardigrade, especially the RNA that makes the radiation resilience part of the tardigrade and put it inside a mouse. When they did this, they found that the mouse was able to withstand 50% more of the radiation poison.

So we measure this radiation poisoning by seeing like, oh, how much DNA does this radiation destroy? Because when radiation destroys the DNA, that's when we have real sickness problems. They found a 50% reduction in the amount of DNA breaks caused by radiation. And then what was even better about it is this RNA can be very targeted to specific parts of the body. but not the cancer cell. So the radiation could easily get to the cancer cell and destroy the cancer tumor, but not the flesh around the mouse. This might help prevent radiation from chemotherapy

for people going through cancer treatments, but it could even help prevent radiation poisoning from astronauts in outer space. Why is Mars red? We know that Mars is red because of iron oxide, a chemical that has a very distinctly red color. Same thing that gets on your car or on a piece of metal that's been sitting out for a long time. But we know that there are actually at least two different types of rust.

There's a rust that forms under very dry conditions called hematite. And then there's a rust that forms under wetter conditions and that actually has the water molecules in it called ferahydrate. For a long time, scientists thought that Mars was consisted of hematite or the dry condition rust. but a recent study published in nature communications on February 25th found that Mars actually is probably consisted of ferahydrate or the wet version of rust. This means that Mars rusted a lot earlier than previously thought. We know that Mars did have a period when it did have a lot of water on it,

but then this water eventually dried up. Scientists thought that the Mars rusted or became red in this period of dry conditions, but now they think that Mars actually rusted during this period of wet conditions. The scientists discovered this because they simulated the Mars dust using their own grinder and using their own chemical composition and comparing that with photos from Mars. So they took ferrohydrate and hematite. They ground them up into the same consistency of Mars dust, and they looked at the coloring of that and then compared the coloring to that of the satellites.

from the ferahydrate is actually a better match than the hematite. This has implications for how we know that Mars formed and how what its history was. We will be awaiting the return of samples of Mars dust from Perseverance Rover in the years to come, which NASA has projected a return of samples in about the early 2030s. Archaeologists have discovered the first glass brain. In 79 AD, Mount Vesuvius erupted and destroyed several Roman cities, including the famous city of Pompeii. But Mount Vesuvius destroyed other cities too, including one called Herculaneum. Archaeologists were investigating the ruins of this city, and they found a man who just didn't get out of bed in time to avoid the volcano.

But most interestingly, they found shards of this black material that upon further investigation, they found that this was this man's brain. This is the first evidence of a human brain or any type of brain tissue being turned into glass. This has huge implications on what we know happened during this Mount the Sufus eruption. In order for glass to form, a substance has to heat up really rapidly to extremely high temperatures and then cool extremely rapidly. A glass brain is evidence that this man was blasted with heat and then the heat was gone. So now archaeologists are hypothesizing that instead of a slow heating up,

like that was previously thought, like an ash cloud comes down from the volcano that came down and slowly heated up its environment and kind of stuck around for a while, they're now hypothesizing that an ash cloud came from the volcano and whooshed through the town of Herculaneum at least once, heating up this man's brain and then cooling it down rapidly

and turning it into this beautiful glass work of art. And under a microscope, you can see the neurons in the glass. It's a beautiful discovery and a great example of how physics and science can actually tell you a lot about human history. I'm not a huge fan of flies. They get in the way, they get on your food, and black biting flies are the worst. It's really easy to ask God and say, hey, why did you make flies? Like, why couldn't you have made more bumblebees that pollinate the flowers that actually give us honey? Flies seem to be pretty useless. But those are the things. type of questions when God calls us to look closer at his creation. He answers those questions for us

if we just look. And it turns out that flies have an incredible level of complexity hidden within them. And that is very evident in their brain. This amount of complexity came to light last year when scientists unveiled the first ever map of the fly brain. They mapped every single neuron, they labeled all of them, and you can look at this map. and say, wow, that is an actual fly brain. This is the second time ever that they've mapped a brain. The first time was when they mapped one of a worm, a round worm, which only had about 300 neurons in it.

When that map came out, it was amazing. It was like, whoa, we can actually map a brain and we can map the neurons. But scientists were stunned at how they could ever get to a more complex brain. Using the power of citizen science, a little bit of AI, scientists have mapped the fruit fly brain, which has about 140,000 different neurons, all packed within a brain the size of a poppy seed. So today we're going to talk about why this finding is important, why it's interesting, how it shows the incredible complexity, but also how it brings up a couple of challenges to the Christian faith and how scientists might be using it to say something that's not true about the universe. But first, let's talk about why we'd even want to study flies in the first place. Why not human brains? Well, flies have been used for a ton of genetic research. They've been used since the early 20th century in the discovery of chromosomes, genes, RNA. They've been influential in showing that, oh, if you change this gene, you actually can change this behavior in an animal and create these mutations.

But additionally, flies are actually incredibly complex. They actually show long-term memory processes. For instance, there is a study that showed that when presented with two different smells, and then with one smell, a fly was zapped and had pain. That fly was actually able to remember and of long-term memory about which odor had pain and which one didn't, showing complex decision-making and memory skills, which humans have, but it's amazing to see in something as simple as a fly-brain. I find it fascinating how, although fly-brains and human brains are very,

different. By studying brains such as fly brains, we can actually know a lot more about human brains, which we hardly understand at all. The brain is probably one of the most complex aspects of God creation. We're hardly close to understanding the entire thing. Even if we studies are coming out all the time and saying, oh, we know this about the brain, we know this, there are so many things we still don't know. But we have come a long way since the 17th century when scientists and philosophers like Renee Descartes believe that the brain's primary function was to control the animal spirits that run through the body to control muscle movement. Descartes wasn't that far off.

Instead of animal spirits running through our body, we have neurons and nerves that control our body. So neurons are tiny cells within the brains that send electrical signals to other brains, and it's these electrical signals that allow us to think, move, have memories, and see when the neuron was discovered as revolutionized neuroscience. People realize that you can look at the brain

and say, oh, this part of the brain is thinking this, or this part of the brain does this, and this part of the brain does this. We now know that different parts of the brain generally have different functions. Like the brain stem is at the bottom of your brain. It controls breathing movements, heartbeats, things that you do involuntarily. And then the frontal lobe deals with planning, problem solving, decision making, even parts of personality. And there are lots of different parts of the brain that are really cool. But there are also things that we are still discovering more and more.

Like scientists recently, I believe in the past month, found out the part of the brain that controls the immune system that tells when the body to go attack something. We didn't know what part of the brain controlled the immune system for all this time of human history. We just recently discovered it, which is super cool. But the brain provides so many questions about can everything we do be mapped to a certain part of the brain? And one of the end goals of neuroscience is to eventually predict or be able to say with absolute certainty, if you do this, this part of the brain will light up and react and then possibly be able to control that aspect. Because if our brain is just electrical signals, maybe we could send electrical signals ourselves artificially through certain parts of the brain and get people to do this. This has been shown to be successful through projects like NeurLink, which Elon Musk has done.

You can use brain electrical signals to control people's movements and their thoughts, which is kind of scary sometimes. But ultimately, neuroscience actually doesn't go as far as people think to explain things. And you actually kind of see that with this new map of the brain that comes out. When this new map of the brain was unveiled, a lot of the scientific community are like, no way, this is amazing, it's huge. We're going to discover about everything that the fly does and this map will be able to do. explain everything it does. Actually, turns out it doesn't. But to understand that, we have to explain a little bit more about the history behind this paper. So, several papers were published in October that revealed the first neuronal map of the fruit fly. The project was called flywire. And this map of a

fly is called a connectome, which is maps of brains. We've mapped parts of brains before, like we've even mapped parts of human brains. We haven't mapped the entire human brain because there are over 86 billion neurons in the human brain when there are only 140,000 neurons in the fly brain. So easy, piece of cake. The scientists did this by taking electron microscopy, which is a way of sending electrons at something and then watching how the electrons bounce off of them to take images. They took this fly brain and they sliced it up.

They used electron microscopy to analyze every single slice. And then they took those slices and they sent that slices off to Google and its AI team. An AI was able to take these images and map every single neuron and create this 3D map of the connection. But we can't entirely trust AI. So using a citizen science platform,

they had volunteers and researchers from around the world proofread each neuron connections, which is super cool, and say, okay, this neuron does actually connect to this. This AI was right. And so the pictures were taken in about 2018, and then it's taken about seven years in order to get from these pictures to finally this map that we can officially say like this is the fruit fly brain.

And this map has some interesting findings. Like for instance, it showed that the brain mostly has left-right symmetry, as in the left side of the brain is pretty similar to the right side of the brain fly. But they did find some asymmetries. They found some parts that actually weren't same. Additionally, it improved scientist's knowledge of how the neurons are connected. to each other. One researcher used this map of the brain to identify the circuits that cause the flies to stop walking. And then another researcher kind of tested this method, this map, to see if it actually worked using taste processing. So they found the neurons that simulate taste. Researchers

tested this model by doing a few simulations on it. For instance, they know that, okay, this is the part of the brain that simulates taste. And if a fly tastes something, it should stick out its tongue. And so using a simulation, they took this map of the neuron, and they said, okay, we're going to stimulate this part, the taste part, they made the simulation taste something, and then the simulation outputted the electrical signals that put out the tongue, showing that the map is pretty accurate. Now why is this useful?

When scientists created the worm diagram of 340 neurons, it allowed them to discover very specific behaviors in real time. They discovered that neuron, the neurons that responded to light, this worm lives underground and is usually not in contact with light. And so it's kind of interesting that it would have neurons that respond to light. But using this map, researchers, they will say, whoa, no way, this does respond to light. So that's an example of something that could be discovered with the fly brain. We know so much about fly behaviors and how they work and reproductive activity because flies have been used for maybe since like the beginning of genetics to do tests on if we change this gene, if we change this neuron, what happens?

Almost, it's been one of the most influential animals on scientific research. And this map of the fly brain will only help further that research. This is a remarkable achievement. But it brings up a big question. Does this mean we can eventually simulate an entire brain? If we can map every single neuron of a fly brain, why can't we then predict every single behavior? behavior that a fly is going to have, is it possible to contain this complexity in a simulation? And then could human brains eventually be uploaded to a simulation?

I have consciousness like that? This brings up some big questions. However, this map of a fly brain actually shows that there are so many things that we can't understand about a fly brain. Even though we can map every single neuron, there are still big limitations. One of those is that this brain cannot describe neural. function in real time. You can't see how the electrical signals travel as just a static picture. For this one type of fly, too, what about different fly brains and how they vary as well?

It would require more mapping of other flies to see how different brains are different from each other. You can't see how the brain moves in time. Additionally, the map does not show synaptic weights, which is the strength of connections between neurons. Every time we learn something new or learn a new skill. We're actually strengthening the connections between neurons. And that tells a lot about who we are, like our personalities and our memories are formed by these synaptic weight connections. But a map of the brain doesn't have that between them. It only shows the connections as they exist. Now, not as their ability to be strengthened or which neurons are used more than others. Additionally, there are other chemicals that exist in the brain fluid that influence how

flies think and how we think. And the map loses information. from that too. Our brains are constantly learning, constantly changing, and a static map can't capture that. If anything, this map shows the limitations of what might be possible. It's taken seven years to get only 140,000 fly neurons, and even then we don't know everything about how the fly works or how it can possibly think. We'll be discovering new neurons and new parts of it. We won't know everything about the fly brain, but we have learned so much just. by this map. And this map shows the incredible complexity of the creator all packed into the fly brain. And then the even more amazing part is that there's so relatively few neurons for such complexity.

The fly shows interesting mating behaviors. It actually has memory. Its eyes can see over 180 degrees in its range of vision. Even though we spent over 100 years studying the fly, its genetics, and its brain, there stills a lot we don't know about this tiny organism. If we can't understand how a simple fly works, how can we understand how a human brain works or how humans work? Part of worship is continually pursuing how we can know God more through his creation. There will always be limitations to what we can know, but that shouldn't stop us from pursuing curiosity. And every time we uncover something like a map of the fly brain that Jamaica's go, wow, our God is amazing that he's packed so much design and beauty into this tiny little creature. So the next time you look at a fly,

before you swat it, pause and remember that the fly has 140,000 neurons in it that are processing its spatial orientation, where you are, and making decisions. It's not an animal, but it is a part of God's amazing creation. Thanks for listening to Visible Things with your host, Eleanor Whitaker on Radio Free Hills, though, at 101.7 FM.