Learn about how scientists discovered that Venus flytraps can store short-term “memories,” why you shouldn't use real-time updates when waiting for the bus, and how epigenetics can make your DNA change within your lifetime.
Learn about how scientists discovered that Venus flytraps can store short-term “memories,” why you shouldn't use real-time updates when waiting for the bus, and how epigenetics can make your DNA change within your lifetime.
Venus flytraps store short-term ‘memories’ in their hairs by Grant Currin
Waiting for the bus? Science says you shouldn't use real-time updates by Kelsey Donk
With Epigenetics, Your DNA Can Change Within Your Lifetime by Ashley Hamer
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Find episode transcript here: https://curiosity-daily-4e53644e.simplecast.com/episodes/venus-flytraps-store-short-term-memories
ASHLEY HAMER: Hi. You're about to get smarter in just a few minutes with Curiosity Daily from curiosity.com. I'm Ashley Hamer.
NATALIA REAGAN: And I'm Natalia Reagan. Today, you'll learn about how scientists discovered that Venus flytrap can store short term memories, why you shouldn't use real time updates from waiting for the bus, and how epigenetics can make your DNA function differently within your own lifetime.
ASHLEY HAMER: Let's satisfy some curiosity.
NATALIA REAGAN: if you're in the market for a new favorite plant, let me present the Venus flytrap for your consideration. This charismatic carnivore has it all. An appetite for insects and spiders, super sensitive trigger hairs and a trap that can snap shut in a tenth of a second. If you aren't sold, there's one more standout quality. The Venus flytrap doesn't have a brain. Sorry, plants. But it does have a short term memory, and researchers have finally figured out how it works.
See, those sensitive hairs are what trigger the plant to close its trap. But it wouldn't be smart for a Venus flytrap to chomp down every time one of its trigger hairs is activated. There would just be too many false alarms. That's why the plant has evolved a policy. It only closes if its system of trigger hairs is tripped twice in 30 seconds. The first signal starts the clock. And the second signal, if it comes, tells the jaws to snap.
Researchers have been trying to get to the bottom of this mechanism for a while. But the plant wasn't ready to give up its secrets. The recent breakthrough came after a team used genetic engineering to peer inside the plant's tissues. The researchers started off with the hypothesis that calcium plays an important role in the plant's short term memory. So they inserted a gene that makes the plant cells produce a protein that glows green when exposed to calcium.
That's when the fun started. To conduct the experiments, the researchers just tapped to trigger hair. And instant later, those genetically engineered proteins started lighting up. In a few tenths of a second, calcium had flooded the entire surface of a specialized leaf that acts like the plant's mouth. After a few seconds, the calcium slowly started to fade. And without a second tap, it returned to its resting state. But when the researchers did trigger a hair for a second time, the calcium levels shot through the roof and the trap snapped close.
This trick definitely puts Venus flytrap at the top of the cool plants list. And if this has thinking about buying one as a pet, go for it. But do your research. They're endangered in the wild, but breed just fine in captivity. So make sure you buy yours from a reputable plant nursery. If you don't, they'll remember.
ASHLEY HAMER: In the past few years, public transit in lots of cities has gotten a high tech facelift. Instead of checking a paper schedule, lots of people now check for real time updates on an app. Sounds more efficient, right? Well, not quite. A new study says that if you want to spend less time waiting for the bus, you actually shouldn't use real time updates.
In fact, according to the study, people who use transit apps to time their arrival at the bus stop to meet the bus right on time actually end up missing the bus 75% of the time. Why? Well, save the app tells you your bus is running 5 minutes late. So you take your time finishing up breakfast before walking to the bus stop. While you're putting your cereal Bowl in the dishwasher, the bus driver might make up that lost time. And you end up missing the bus.
To come to this conclusion, researchers spent a full year analyzing bus traffic in Columbus, Ohio. They compared the real time traffic predictions on the transit app to when buses actually showed up at bus stops. Then they calculated how much time riders would spend waiting for the bus depending on the strategies they used to minimize wait time. Riders who end up missing the bus use what they called the greedy tactic.
Here's how it works. Commuters use the real time app to figure out exactly when the bus will arrive and then they timed their own arrival to match. According to the study, greedy bus riders end up waiting about 12 minutes for the bus on average. That's because the apps don't regularly update the buses location data and bus drivers are incentivized to make up for lost time. So you can easily end up behind schedule.
Luckily for bus riders, the researchers figured out the best strategy for catching the bus on time and minimizing wait time. The best strategy, just follow the schedule. People who just turn up according to the bus schedule weighed about three times less than greedy riders. But if you really want to use the real time app, just make sure to add some buffer time. You might still have to wait a few minutes, but you probably won't miss the bus altogether.
NATALIA REAGAN: Everybody knows that you inherit DNA from your parents and pass it down to your kids. That DNA doesn't change. The genes you had as a baby are basically the same genes you have when you kick the bucket. But it turns out the way your DNA operates can change in your lifetime. That's through something called epigenetics. And it sounds almost too wild to be true.
So when you think about DNA, you probably imagine that classic double helix structure that looks like a twisted ladder. What you may not imagine is how that structure exists in your body. Those ladders are wound around marshmallow shaped complexes of proteins called histones. And how tightly their wound affects how easily the genes and that part of the DNA can turn on or be expressed.
Epigenetic markers on the histones influence that winding, and therefore influence gene expression. At its very basic level, epigenetics is how the exact same DNA that codes for a liver cell can also code for a brain, heart or blood cell. It turns off a few genes here and turns on a few genes there. And all of a sudden, you've got a fully functioning organism made from all sorts of different cells.
But at a more mysterious level, epigenetics may also be the cause of all sorts of changes throughout your life. Exercise for example, may change the epigenetic markers in muscle and fat cells. The plastic additive BPA may have disease causing epigenetic effects. The same goes for childhood trauma, which could explain why abuse victims have a higher risk of disease as adults. Even weirder, there's some evidence that these effects can be passed down.
A study from 2002 found that living through a famine affected the cardiovascular risk of the survivors' grandchildren. And a 2017 paper showed that famine could lead to smaller offspring two generations. Later other research suggests that the risk of obesity, diabetes, and heart disease could also be passed on through epigenetics. But what's not clear is how long these changes last.
One study in roundworms found that epigenetic changes in one generation could last up to seven subsequent generations. But fortunately, humans aren't roundworms. When it comes to the changes scientists have seen in humans, they can't rule out DNA mutations or the effects of gut bacteria. But when it comes to genetic changes in a person's own lifetime, there's no doubt, epigenetics is very real.
ASHLEY HAMER: All right. Well, let's recap what we learned today starting with the fact that the Venus flytrap has a short term memory. It lets them to catch prey when their tiny trigger hairs are activated twice in 30 seconds. What timing. Scientists figured out that these Venus fly traps use calcium to determine when it's really prey that made the terrible mistake of landing on their open jaws and not a raindrop or a piece of dust.
NATALIA REAGAN: I just think this is fascinating and terrifying. I mean, we did an episode recently about growing insects in an oxygen rich environment. Imagine if we did that with Venus flytrap. Will they become giant, and would we have an Audrey too on our hands?
ASHLEY HAMER: Oh, my goodness. Can you imagine instead of worrying about coyotes for your outdoor cats and dogs, worrying about the neighbor's Venus flytrap?
NATALIA REAGAN: Or toddlers.
ASHLEY HAMER: Or toddlers. Yeah.
NATALIA REAGAN: And we learned that when it comes to waiting for the bus, it's better to stick with the paper schedule or the plan schedule and not the real time updates since bus drivers are skilled at making up time. And so you might miss your bus if you don't think they might shave some time off their real time updates. I mean, I'm a driver. I know that you can do that.
ASHLEY HAMER: Yeah, I mean, I'm so guilty of this. And it's been months since I've had to catch a bus. But when I did, every time, every time, I thought I was outsmarting it. Like oh, yeah, it's 3 minutes away, and I'm 3 minutes from the bus stop. This is perfect. And then I get there, and the bus has already left. And I don't know why I don't learn.
NATALIA REAGAN: It's tough though. So I grew up in Los Angeles where I took the bus as a kid. But when I got older and I finally drove, I didn't really take the bus very often. The bus system wasn't as good as it is now honestly. But when I moved to New York, I rely on the bus. And I live in an area of New York where there are no subways. There is just the bus or a bike. And so I have been schooled harshly by this real time update, harshly.
And I don't know about you, but I've done the bus chase where I like cry, run down the street usually in the wrong, the most sensible shoes possible.
ASHLEY HAMER: Yep. I'm extra proud when I can catch a bus that I'm running down in really girly shoes. It's an extra challenge. And I feel very proud and vindicated. And finally, we learned that while your DNA doesn't change in your lifetime, the way your DNA is expressed can be altered by everything that happens to you in your lifetime from trauma to nutrition to exercise to environmental factors.
This principle is known as epigenetics. And it refers to the way that your DNA can switch on and off certain genes based on your life experiences, including maybe the life experiences of your grandparents. How wild is that.
NATALIA REAGAN: Epigenetics is one of my favorite new fields of study honestly. And I love talking about it because it's just this idea that it's this epigenome that sits above-- epi. Sits above your DNA, your genome. So I think of your genome is your hardware. It doesn't change. It is what it is. The epigenome is that software. And when you get new software updates, it turns on and off genes.
And so that's why things like stress or terrible things like institutional poverty or racism can actually make you sick. And I have friends anthropologists who are doing really interesting and also heartbreaking research about these certain institutional poverty or racism that is actually leading to higher risks of heart disease and diabetes and things of that sort. And it's something that can be mitigated when you cut down those sort of social issues.
ASHLEY HAMER: It really is. Natalia, I feel like you would know. How is epigenetics different than Lamarckism, which is where Lamarck said that giraffes have long necks because they reach for leaves on taller trees? How is that different? Because we know that's wrong.
NATALIA REAGAN: I mean, the difference is obviously the hardware is always there, and how these genes are expressed. So it might be things that can be eventually cured, like for instance, height in the case of the giraffe, had a longer neck and became taller. That gene for height is not going to get turned on and off because height for instance, is influenced by multiple genes and the environment.
So it's a little bit more complex than just like, oh, a gene is turned on or off. You'd have multiple genes turn on and off and the environment playing a role. Whereas in this particular case, if it's like insulin production for diabetics or heart disease or things like that, it might be a little bit more simplistic of the turning on and off genes versus something as big as is height. A species becoming--
Because in that case, we're talking about speciation or massive mutations that would lead to some sort of potentially new species of giraffe.
ASHLEY HAMER: Totally. It sounds like maybe Lamarckism is a little too simplistic. He's probably right about the fact that things can change based on your environment and you can pass those things down. But he was wrong about how.
NATALIA REAGAN: Yeah, I mean, it wasn't even what traits. It's about how it happens. It doesn't happen in one's lifetime. And so and that's why it's so interesting that it's not necessarily exciting-- I talk about this a lot like how everything that you do in your lifetime starting in utero, and even before that when we talk about grandparents and how your grandparents stress might affect you or your parents stress might affect you and in your own lifetime. It's interesting.
And again, this is still a field that's getting a lot of development. So I think still is more research is needed. But we are seeing that things can change within your lifetime. But I think you can change them back. It's not necessarily like you're stuck in one spot, which I think is really interesting.
And I think for me as somebody who's constantly stressed out and has a lot of anxiety, I'm trying to do things like meditate and find ways to mitigate the stress only because I feel like if I do have children, I'm doing a disservice to them.
Today's stories were written by Grant Curran, Ashley Hamer and Kelsey Donk, and edited by Ashley Hamer who's the managing editor for Curiosity Daily.
ASHLEY HAMER: Scriptwriting was by Natalia Reagan and Sonia Hodgson. Today's episode was edited by Jonathan McMichael and our producer is Cody Goff.
NATALIA REAGAN: Beware the Venus fly traps and join us again tomorrow to learn something new in just a few minutes.
ASHLEY HAMER: And until then stay curious.