Speaker 1: Welcome to Stuff from the Science Lab from how stuff
Speaker 1: works dot com. Wow, hey guys, and welcome to the podcast.
Speaker 1: This is also and I don't know, the science editor
Speaker 1: how stuff works dot com. And this is Robert Lamb,
Speaker 1: science writer at how stuff works dot com. Uh, tell
Speaker 1: me something else. And have you ever stared in the
Speaker 1: mirror and tried to watch yourself aging? Um? Not really
Speaker 1: because aging is kind of hard to detect, and you know,
Speaker 1: apart from rooting around and seeing if there are any
Speaker 1: gray hairs or whatever. Yeah, I know there's that one.
Speaker 1: Um no because it sounds kind of boring, you know, Um,
Speaker 1: But but no, But I mean there's there's like a
Speaker 1: YouTube video that the guy who like took a picture
Speaker 1: of himself like regular increments and then like put them
Speaker 1: all together in like a like a slide show, you know,
Speaker 1: and like like that's an example where you could you
Speaker 1: could actually watch yourself age a little. But but but
Speaker 1: not by just looking into the mirror, right right, It's
Speaker 1: hard to detect, but we know what's going on. I
Speaker 1: remember going to an exhibit at the Moment in New
Speaker 1: York City a while back, and I got this book
Speaker 1: and it was a photography exhibit and the photographer took
Speaker 1: pictures every year of these four sisters, and so flipping
Speaker 1: through the book, um, you could see these women aging,
Speaker 1: you know, just as you've flipped. And it was so
Speaker 1: cool and it was so interesting. I really, I really
Speaker 1: dug that. But yeah, aging is definitely hard to to
Speaker 1: notice unless you've had a couple of gray hairs poking
Speaker 1: out over Now, how do you know people were actually aging?
Speaker 1: How do you you know you're actually aging? Let's see
Speaker 1: the proof of it. I don't see aging right now? Right,
Speaker 1: you look like you're getting a little older doing this podcast.
Speaker 1: It wasn't that makes it sound like your hair sprouting
Speaker 1: out of those earphones. Yeah, well that just means I
Speaker 1: need a haircut. But but the point I'm trying to
Speaker 1: make here is that another area that is very difficult
Speaker 1: to observe, and one of the criticisms often thrown at
Speaker 1: it is how do you know there's evolution? Like like
Speaker 1: we can see it. Yeah, we're let's see some evolution.
Speaker 1: I don't. I don't believe in evolution. Puts some on
Speaker 1: the table, dish out some evolution. Let's yeah, get put
Speaker 1: in a bag. You can't do it, you know, because
Speaker 1: it's uh, because evolution occurs at increments over a very
Speaker 1: long period of time from generation to generation, right, And
Speaker 1: if you consider that Darwin's origin is species hasn't even
Speaker 1: been in print a mere hundred fifty one years, which is,
Speaker 1: you know, kind of a trap in the bucket. Yeah,
Speaker 1: that's nothing on on an evolutionary scale, right, So consider
Speaker 1: you know, how short of a time period we've been looking.
Speaker 1: And that's not to discount the fossil record, because of
Speaker 1: course the fossil record does in fact provide us a
Speaker 1: good understanding of what's gone on in the past for organisms. Yeah,
Speaker 1: but one of the things with with looking back at
Speaker 1: fossils as you have like definite frozen moments in time,
Speaker 1: you know, in these different forms. But but it's it's
Speaker 1: much harder to see the movement, to see like the
Speaker 1: change from one form to the next, you know. Yeah,
Speaker 1: So we thought we'd cover a couple of evolution in
Speaker 1: action studies today. Yeah. Yeah, these are examples of evolution
Speaker 1: in action and they're they're just great examples to really,
Speaker 1: you know, make evolution come alive to a certain extent,
Speaker 1: and they're occurring today. Yeah, So let's talk about the lizards.
Speaker 1: I feel like we always talk about lizards. Yeah, well
Speaker 1: lizards are great, pretty great, and uh yeah, we have
Speaker 1: a couple of studies. The first one is really cool.
Speaker 1: This was a two thousand nine Pin State study and
Speaker 1: it dealt with these little fence lizards, you know, kind
Speaker 1: of like these little dudes you see running around, you know, everywhere. Yeah,
Speaker 1: and they're suffering from an invasion from the south fire
Speaker 1: ants guys. Yeah. And and they're they're in an area
Speaker 1: where they've just over the several decades have suddenly had
Speaker 1: to deal with fire ants and they've never had to
Speaker 1: deal with them before. Um, and so this is this
Speaker 1: is a hallmark of evolution. You know, you have a
Speaker 1: species and suddenly the game has changed. You know, we
Speaker 1: have new food, we have new enemies, we have conflict. Yeah,
Speaker 1: because the the food thing is key, because it's not
Speaker 1: what you think the fire ants can eat the lizards.
Speaker 1: I was surprised by that. I mean you would think,
Speaker 1: obviously the lizards are going to come out on top here,
Speaker 1: but they're not, at least not the ones that are
Speaker 1: newly exposed to the fire ants. So let's get into
Speaker 1: the details of the study. Yeah, so what what they
Speaker 1: decided to do was was to look at these like,
Speaker 1: not all the lizards are have encountered fire ants, yet
Speaker 1: some have been dealing with them for as long as
Speaker 1: like sixty eight years. Yeah. So they had four different groups, right,
Speaker 1: and they were looking at four different groups of lizards
Speaker 1: that had been exposed to fire ants in different increments.
Speaker 1: One group had never encountered fire ants, and then like
Speaker 1: one had encountered them for like twenty three years, another
Speaker 1: encountered them for somewhere they were like forty something years,
Speaker 1: and then the fire extrain. There's the group that had
Speaker 1: been dealing with them for sixty eight years. They were
Speaker 1: sixty eight long years of fire ants veterans of the
Speaker 1: Great Lizard fire ant War right there. So the researchers
Speaker 1: were trying to figure out, with time as a factor,
Speaker 1: how yeah, how they've adapted to this this new stimuli,
Speaker 1: you know, and which ones are going to be better
Speaker 1: situated to deal with it. And apparently like the main
Speaker 1: defense against fire ants is too is to basically move
Speaker 1: your butt because because in the in the group that
Speaker 1: it like never encountered them before, like they will just
Speaker 1: sit there apparently, and the fire ants will crawl over
Speaker 1: them and the lizards defense is like, oh, I'm just
Speaker 1: gonna be real still still and shut my eyes. Yeah.
Speaker 1: And they took it. Yeah, and then they just get
Speaker 1: them Yeah. Whereas the ones that are used to it,
Speaker 1: they'll know, hey, I need to move and or they
Speaker 1: flick them off. They flick them off or the leap away,
Speaker 1: you know, et cetera. Um, they have learned to deal
Speaker 1: with it. So they the researchers observed this behavior whether
Speaker 1: the lizards could you know, take it or get the
Speaker 1: heck out of there, But they also were interested in
Speaker 1: looking at the hind leg lengths of all the lizards.
Speaker 1: Would they find Roberts Well, they found that lizards living
Speaker 1: near fire ants are they're developing behaviors to increase their
Speaker 1: survival and and evolving longer hind legs in response to
Speaker 1: the attacks from the fire ants. Okay, and so that
Speaker 1: was that was their exposure. It was the exposure the
Speaker 1: length of exposure that correlated. Yeah, And I should also
Speaker 1: mention that I believe one of the details in the
Speaker 1: study was that they didn't like kill a whole lot
Speaker 1: of lizards in this like I think they were. They
Speaker 1: were like saving the lizards before they could be stung
Speaker 1: to death. That's nice. Yeah, but so as cool as
Speaker 1: the study is, it's not quite speciation now. It's more
Speaker 1: like these are the movements though that that can lead
Speaker 1: to it. But yeah, this is not These lizards aren't
Speaker 1: becoming a new breed of lizard, a new species of lizard. Um.
Speaker 1: But let's talk about where speciation may be occurring, in
Speaker 1: fact in White Sands, New Mexico. Yeah, this is another
Speaker 1: lizard study. This is a two thousand ten University of
Speaker 1: Idaho study. And I actually talked to one of the
Speaker 1: people tied up in the research for this for this
Speaker 1: a story for Discovery News January UM. And this one
Speaker 1: deals with these brown lizards. Traditionally brown lizards. Uh that
Speaker 1: they but they live in an area called White Sands,
Speaker 1: New Mexico. And why do you think it's called White Sands,
Speaker 1: New Mexico because there's white sand everywhere. Sounds kind they're
Speaker 1: a brown lizard though, Yeah, And what is a lizard
Speaker 1: and what is a lizard? One of the lizards traditional
Speaker 1: defense mechanisms camouflage, camouflage, so the the but they, of course,
Speaker 1: these lizards have changed over time over the course of
Speaker 1: say two to five thousand years, right, since they arrived
Speaker 1: there a couple of thousand years ago. Yeah, so so
Speaker 1: they were they were exploring how they've they've changed pigment
Speaker 1: during this time. They've they've become these like white lizards
Speaker 1: and white sands. Yeah and uh. Anyway, they made the
Speaker 1: argument that that this is really one of the they're
Speaker 1: hit they've hit several of the road stops on the
Speaker 1: way to speciation. Um and uh. And you know, they've
Speaker 1: they've changed their color, that's a big one. But also
Speaker 1: they've started, uh having a preference for light colored lizards
Speaker 1: when it comes to breeding. Really. Yeah, so it's like there,
Speaker 1: you know, it's sort of like imagine you know, it's
Speaker 1: like a line, you know, and one line is diverging
Speaker 1: slowly from the other. So you know, have you know,
Speaker 1: another ten thousand years, you know, you might have the white,
Speaker 1: the whitelizard, and the brown lizard of separate species entirely.
Speaker 1: So that's pretty cool, but not as cool as the
Speaker 1: equal I. Yeah, this this is a fantastic study and
Speaker 1: you guys may have heard it. It goes back to
Speaker 1: what we were talking about with the generations. You know,
Speaker 1: it's like human generations. Um, it's hard, it's hard to
Speaker 1: really you know, we can't really watch it spread from
Speaker 1: generation generation. There haven't been that many generations since origin
Speaker 1: of species, you know, et cetera. But if you can
Speaker 1: find a species that has really small generations, a short
Speaker 1: life cycle, short lived, it's like pushing the fast forward
Speaker 1: button right right, And a lot of times that the
Speaker 1: choice organisms might be drosophilia, your fruit flies, or or
Speaker 1: planel bacteria. And in this case in back in it
Speaker 1: was equally a single equally bacterium that in Michigan State
Speaker 1: University biologists used and he started twelve laboratory populations with it. Yeah,
Speaker 1: this is Professor Richard Lynsky. Twenty years time. Lensky had
Speaker 1: generations on his hands. So if we were studying humans,
Speaker 1: this would be a phenomenal amount of time. Yeah, we'd
Speaker 1: be talking something in the neighborhood of like three million
Speaker 1: years of human evolution. So Lensky observed the bacteria as
Speaker 1: they grew larger and faster in response to the lab diets.
Speaker 1: Then what happened, Well, you hit around the thirty one
Speaker 1: five generations, something special happens. Suddenly they're able to this
Speaker 1: one population of them are able to consume citrate, which
Speaker 1: is as nutrient that they've they've been surrounded by the
Speaker 1: whole time as as part of their medium. Yeah, their medium. Um,
Speaker 1: it's kind of like like imagine if you were like,
Speaker 1: it's like that they're gonna bring up the cats. That
Speaker 1: was one of my more way too complicated metaphor. Probert
Speaker 1: has to find a way to work in cats into
Speaker 1: every podcast. It was just kind of like the buffet
Speaker 1: bar was there and they were eating most of it,
Speaker 1: and then one day suddenly they were able to eat
Speaker 1: the seafood portion of the buffet. Good. Good for them.
Speaker 1: But in this case it was the sit rate. So
Speaker 1: suddenly you had situate plus E. Coli. Yeah, so you
Speaker 1: went up with the population of mutated sitrate consuming bacteria
Speaker 1: and as you can imagine, that was a pretty handy
Speaker 1: ability to have, and so the population of that bacteria skyrocketed.
Speaker 1: And now they call these sitrate plus equally. So here's
Speaker 1: also something very interesting about this experiment. You know, somebody's
Speaker 1: going to dismiss it as a one time thing, oh,
Speaker 1: as a fluke or whatever it as well, Lensky had
Speaker 1: a solution for this. So the whole time he and
Speaker 1: his team had been freezing samples every five hundred generations,
Speaker 1: so he was able to do a rewind and he
Speaker 1: was actually able to go back and replace some of
Speaker 1: the experiment and see if they could catch it again.
Speaker 1: I mean, this is so cool. Yeah. Yeah, And and
Speaker 1: apparently they were like when they went back and they
Speaker 1: like replayed it, they were they found it like something
Speaker 1: was occurring in this in this one population at like
Speaker 1: the at the twenty thousand or so generation, like some
Speaker 1: small changes that were leading up to this ability to
Speaker 1: metabolize sits. Right. Yeah, and they're still working to figure
Speaker 1: out exactly what. Okay, so that's the question. Yeah, you know,
Speaker 1: what is the mechanism way? I mean, if they could
Speaker 1: pinpoint it just a little bit more, that would be great. Yeah,
Speaker 1: I just get down to the we have the fine
Speaker 1: changes that are occurring. It reminds me a lot. I
Speaker 1: think there was like a Twilight Zone where like like
Speaker 1: the humans were observing the evolution of like a micro
Speaker 1: biological so it wasn't it was more than micro biological.
Speaker 1: It's like a tiny little civilization and like they watched
Speaker 1: them grow, you know, developed like spaceships and stuff. And
Speaker 1: I think the Simpsons, so on a more sobering note, um,
Speaker 1: the ability of bacteria to evolve, or any organism to
Speaker 1: evolve has pretty important implications, as you guys know. Um,
Speaker 1: you know, especially when you're talking about our fifty plus
Speaker 1: year war against harmful bacteria, when you're talking about things
Speaker 1: like extensively drug res stant tuberculosis UM, and then there
Speaker 1: are other So that's that's definitely yeah, in the in
Speaker 1: the same way that these citrate plus a cool I
Speaker 1: were suddenly able to deal with something in their environment
Speaker 1: that they hadn't you been around for too terribly long.
Speaker 1: You know, we're having having some very harmful microbes out
Speaker 1: there that are you know, figuring how to out how
Speaker 1: to deal with the situations that we're throwing at them.
Speaker 1: I will tell you as a parent, it's sometimes terrifying
Speaker 1: to give your kid antibiotics. You know, I wonder, you know,
Speaker 1: is my kid going to evolve resistance to this? You know,
Speaker 1: I it's it's just a little terrifying. And and then
Speaker 1: there's a there's a whole side with insects and pesticides
Speaker 1: as well, you know, where insects developing a resistance to
Speaker 1: certain pesticides over time. We you know, we throw out
Speaker 1: these solutions and we don't really realize that that nature
Speaker 1: is pretty good at evolving. It's pretty much all it does,
Speaker 1: you know, So given enough time, you know, it's it's
Speaker 1: remarkable what people think, you know, especially micro organisms will
Speaker 1: be able to do. Like I was reading something of
Speaker 1: the day researching stuff about plastics, and there are some
Speaker 1: some predictions that like you know, you know, like tens
Speaker 1: and thousands of years, like you know, you'll you'll eventually
Speaker 1: have microbes that can can really break down plastics in
Speaker 1: a way that we can't. We don't see today because
Speaker 1: it's some new material. But give him enough time, they'll
Speaker 1: figure it out. Yeah. In the meantime, maybe just bring
Speaker 1: your bags off to use plastic. Yeah, yeah, that's always
Speaker 1: always a good idea. So, speaking of plastic bags, we've
Speaker 1: got a plastic bag here full of reader mail. Let
Speaker 1: me grab when happen. They didn't really readers, some of
Speaker 1: them are readers, but listeners primarily listeners, I guess. Um. Yeah,
Speaker 1: so we got one here from Alicia. Oh. Alicia, she
Speaker 1: was the one who wrote into for to share her
Speaker 1: favorite bit of cosmos. Yeah. Yeah, she's one of She's
Speaker 1: a fan of some of our more cosmic entries in
Speaker 1: the podcast series. Here and she says, Hey, Alison and Robert,
Speaker 1: this is a little something that I remembered after listening
Speaker 1: to your podcasts about the birth of stars and planets.
Speaker 1: Though this one this is more relevant to the death
Speaker 1: of stars. I just wanted to share my favorite factoid
Speaker 1: ever from cosmology. It was on casts the quote plasma
Speaker 1: soup unquote that resulted from the Big Bang consisted of
Speaker 1: only very small particles like protons, electrons, et cetera. But
Speaker 1: there weren't any heavier elements that would have higher atomic numbers.
Speaker 1: But from what I can tell from my simplistic understanding
Speaker 1: of physics, when stars began to coalesce, the force of
Speaker 1: gravity pulling on the outside of the stars would cause
Speaker 1: immense amounts of pressure on the particles in the middle,
Speaker 1: causing the nuclear fusion reactions and creating heavier and heavy elements. Thus,
Speaker 1: large stars will be able to create heavier, large, heavier
Speaker 1: elements closer to their centers. Then, if the star dies
Speaker 1: and becomes a supernova, it sends its particles scattering far
Speaker 1: and wide throughout the galaxy to later clampman become part
Speaker 1: of other stars, planets, and what have you. While I'm
Speaker 1: normally not a romantic. This literally means that we are
Speaker 1: all made of star dust. So yeah, that's that's awesome.
Speaker 1: You know, we're all we're all star stuff. So that's
Speaker 1: that's kind of meat. It kind of you know, builds
Speaker 1: the soul like community of the universe. You know, we
Speaker 1: are the universe and the universe is us. Yeah, thanks
Speaker 1: Felicia and uh oh, and then we have another one
Speaker 1: here from uh oh thoughts from Alison ladder Milk. At first,
Speaker 1: that would really be cheap. You're writing in your own
Speaker 1: fan now sending anything listener will This one's from Natalie. Oh, Natalie,
Speaker 1: we even about right. Oh yeah, this's a long one.
Speaker 1: There we go. Not as long as someone and if
Speaker 1: you just read some of the highlighted carts, okay, um,
Speaker 1: she says, first of all, I just want to say
Speaker 1: I'm a big fan of the show. I'm addicted to
Speaker 1: listening to the podcast just before bed or in the
Speaker 1: quiet moments of my free time. So we should really
Speaker 1: keep the yelling down. You might be trying to get
Speaker 1: to sleep. Um, that's I'll keep paying money. Your topics
Speaker 1: are always very engaging and informative. Whenever I listen, I
Speaker 1: feel like I'm getting a brush up on concepts I
Speaker 1: missed while zoning out in high school science classes. Which
Speaker 1: is great, that's totty much as part of the whole
Speaker 1: mission Here, she says, I just finished listening to your podcast,
Speaker 1: A World Changing Science Experiments, Part two and was very
Speaker 1: interested in section on Pavlov and his experiments with dogs,
Speaker 1: but had to send any meddle. Let you know I side. Now,
Speaker 1: let you know a side of path Law that is
Speaker 1: generally unknown to most. I just graduated in May two
Speaker 1: ten from CVE Denver with a bachelor's degree in psychology,
Speaker 1: and during my history of psychology class, we discussed path
Speaker 1: Law's work in great detail. I was surprised and disturbed
Speaker 1: to find that Pavlov used children orphans in fact, in
Speaker 1: the same manner as dogs and his experiments. I had
Speaker 1: never heard. Yeah, and once he discovered that he could
Speaker 1: condition any unconditioned response, he wanted to see if humans
Speaker 1: humans would react in the same way. She goes on
Speaker 1: to say, much of my surprise, my professor showed a
Speaker 1: video of path Law working with both his children and
Speaker 1: his dogs, or both his dogs and these children. Despite
Speaker 1: this discovery, I'm still a fan of Pavlov's as his
Speaker 1: work was pivotal and understanding learning and behavior in humans
Speaker 1: and other animals. Again, I love the show and that's
Speaker 1: great because that's I mean, that's always my experience with
Speaker 1: finding out more about science and science experiments is that
Speaker 1: it's always a little bit amazing and a little bit creepy,
Speaker 1: depends on which side you look at it, you know. Yeah,
Speaker 1: So share your amazing stories or creepy stories with us,
Speaker 1: whether you're on Facebook, we're at a stuff from the
Speaker 1: science Lab, or Twitter we're on lab stuff, or send
Speaker 1: us an email and science stuff it has stuff first
Speaker 1: dot com. Yeah, let us know what you're up to
Speaker 1: and check out those sites and you'll be able to
Speaker 1: see what we're up to. All right, thanks for listening,
Speaker 1: Guys for more on this and thousands of other topics
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